Open MHA Developer Manual

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The Open Master Hearing Aid
(openMHA)
4.5.5

Plugin Developers’ Manual

© 2005-2018 by HörTech gGmbH, Marie-Curie-Str. 2, D–26129 Oldenburg, Germany

The Open Master Hearing Aid (openMHA) – Plugin Developers’ Manual
HörTech gGmbH
Marie-Curie-Str. 2
D–26129 Oldenburg

iii

LICENSE AGREEMENT This file is part of the HörTech Open Master Hearing Aid (openMHA)
Copyright ©2005 2006 2007 2008 2009 2010 2012 2013 2014 2015 2016 2017 2018 HörTech
gGmbH.
openMHA is free software: you can redistribute it and/or modify it under the terms of the GNU
Affero General Public License as published by the Free Software Foundation, version 3 of the
License.
openMHA is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU Affero General Public License, version 3 for more details.
You should have received a copy of the GNU Affero General Public License, version 3 along
with openMHA. If not, see .

© 2005-2018 HörTech gGmbH, Oldenburg

Contents
1 Overview
1.1 Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Platform Services and Conventions . . . . . . . . . . . . . . . . . . . . . . . . .
2 Module Documentation
2.1 Concept of Variables and Data Exchange in the openMHA
2.2 The openMHA Plugins (programming interface) . . . . . .
2.3 Writing openMHA Plugins. A step-by-step tutorial . . . . .
2.4 The MHA Framework interface . . . . . . . . . . . . . . . .
2.5 Communication between algorithms . . . . . . . . . . . . .
2.6 Error handling in the openMHA . . . . . . . . . . . . . . .
2.7 The openMHA configuration language . . . . . . . . . . .
2.8 The openMHA Toolbox library . . . . . . . . . . . . . . . .
2.9 Vector and matrix processing toolbox . . . . . . . . . . . .
2.10 Complex arithmetics in the openMHA . . . . . . . . . . . .
2.11 Fast Fourier Transform functions . . . . . . . . . . . . . . .
3 Namespace Documentation
3.1 AuditoryProfile Namespace Reference . . . . . . . .
3.2 DynComp Namespace Reference . . . . . . . . . . .
3.3 MHA_AC Namespace Reference . . . . . . . . . . .
3.4 MHA_TCP Namespace Reference . . . . . . . . . .
3.5 MHAEvents Namespace Reference . . . . . . . . . .
3.6 MHAFilter Namespace Reference . . . . . . . . . . .
3.7 MHAIOJack Namespace Reference . . . . . . . . . .
3.8 MHAJack Namespace Reference . . . . . . . . . . .
3.9 MHAMultiSrc Namespace Reference . . . . . . . . .
3.10 MHAOvlFilter Namespace Reference . . . . . . . . .
3.11 MHAOvlFilter::FreqScaleFun Namespace Reference
3.12 MHAOvlFilter::ShapeFun Namespace Reference . .
3.13 MHAParser Namespace Reference . . . . . . . . . .
3.14 MHAParser::StrCnv Namespace Reference . . . . .
3.15 MHAPlugin Namespace Reference . . . . . . . . . .
3.16 MHASignal Namespace Reference . . . . . . . . . .
3.17 MHATableLookup Namespace Reference . . . . . .
3.18 MHAWindow Namespace Reference . . . . . . . . .
4 Class Documentation
4.1 algo_comm_t Struct Reference . . . . . . . . . .
4.2 AuditoryProfile::fmap_t Class Reference . . . . .
4.3 AuditoryProfile::parser_t Class Reference . . . .
4.4 AuditoryProfile::profile_t Class Reference . . . . .
4.5 AuditoryProfile::profile_t::ear_t Class Reference .
4.6 comm_var_t Struct Reference . . . . . . . . . . .
4.7 DynComp::dc_afterburn_rt_t Class Reference . .
4.8 DynComp::dc_afterburn_t Class Reference . . . .
4.9 DynComp::dc_afterburn_vars_t Class Reference
4.10 DynComp::gaintable_t Class Reference . . . . . .
4.11 expression_t Class Reference . . . . . . . . . . .
4.12 io_file_t Class Reference . . . . . . . . . . . . . .

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1
1
2

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4
4
6
10
26
27
31
33
34
36
53
58

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64
64
64
66
66
67
68
71
71
73
73
74
75
76
79
80
81
86
87

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88
88
93
94
94
95
95
96
97
97
98
100
100

CONTENTS
4.13
4.14
4.15
4.16
4.17
4.18
4.19
4.20
4.21
4.22
4.23
4.24
4.25
4.26
4.27
4.28
4.29
4.30
4.31
4.32
4.33
4.34
4.35
4.36
4.37
4.38
4.39
4.40
4.41
4.42
4.43
4.44
4.45
4.46
4.47
4.48
4.49
4.50
4.51
4.52
4.53
4.54
4.55
4.56
4.57
4.58
4.59
4.60
4.61
4.62
4.63

v

io_lib_t Class Reference . . . . . . . . . . . . . . . . . . . . . . . . . .
io_parser_t Class Reference . . . . . . . . . . . . . . . . . . . . . . . .
io_tcp_fwcb_t Class Reference . . . . . . . . . . . . . . . . . . . . . .
io_tcp_parser_t Class Reference . . . . . . . . . . . . . . . . . . . . .
io_tcp_sound_t Class Reference . . . . . . . . . . . . . . . . . . . . . .
io_tcp_sound_t::float_union Union Reference . . . . . . . . . . . . . .
io_tcp_t Class Reference . . . . . . . . . . . . . . . . . . . . . . . . . .
MHA_AC::ac2matrix_t Class Reference . . . . . . . . . . . . . . . . . .
MHA_AC::acspace2matrix_t Class Reference . . . . . . . . . . . . . .
MHA_AC::double_t Class Reference . . . . . . . . . . . . . . . . . . .
MHA_AC::float_t Class Reference . . . . . . . . . . . . . . . . . . . . .
MHA_AC::int_t Class Reference . . . . . . . . . . . . . . . . . . . . . .
MHA_AC::spectrum_t Class Reference . . . . . . . . . . . . . . . . . .
MHA_AC::waveform_t Class Reference . . . . . . . . . . . . . . . . . .
mha_audio_descriptor_t Struct Reference . . . . . . . . . . . . . . . .
mha_audio_t Struct Reference . . . . . . . . . . . . . . . . . . . . . . .
mha_channel_info_t Struct Reference . . . . . . . . . . . . . . . . . . .
mha_complex_t Struct Reference . . . . . . . . . . . . . . . . . . . . .
mha_dblbuf_t< FIFO > Class Template Reference . . . . . . . . . . .
mha_direction_t Struct Reference . . . . . . . . . . . . . . . . . . . . .
mha_drifter_fifo_t< T > Class Template Reference . . . . . . . . . . .
MHA_Error Class Reference . . . . . . . . . . . . . . . . . . . . . . . .
mha_fifo_lw_t< T > Class Template Reference . . . . . . . . . . . . .
mha_fifo_t< T > Class Template Reference . . . . . . . . . . . . . . .
mha_fifo_thread_guard_t Class Reference . . . . . . . . . . . . . . . .
mha_fifo_thread_platform_t Class Reference . . . . . . . . . . . . . . .
mha_rt_fifo_element_t< T > Class Template Reference . . . . . . . .
mha_rt_fifo_t< T > Class Template Reference . . . . . . . . . . . . . .
mha_spec_t Struct Reference . . . . . . . . . . . . . . . . . . . . . . .
MHA_TCP::Async_Notify Class Reference . . . . . . . . . . . . . . . .
MHA_TCP::Client Class Reference . . . . . . . . . . . . . . . . . . . .
MHA_TCP::Connection Class Reference . . . . . . . . . . . . . . . . .
MHA_TCP::Event_Watcher Class Reference . . . . . . . . . . . . . . .
MHA_TCP::Sockread_Event Class Reference . . . . . . . . . . . . . .
MHA_TCP::Thread Class Reference . . . . . . . . . . . . . . . . . . .
MHA_TCP::Timeout_Watcher Class Reference . . . . . . . . . . . . .
MHA_TCP::Wakeup_Event Class Reference . . . . . . . . . . . . . . .
mha_wave_t Struct Reference . . . . . . . . . . . . . . . . . . . . . . .
mhaconfig_t Struct Reference . . . . . . . . . . . . . . . . . . . . . . .
MHAEvents::emitter_t Class Reference . . . . . . . . . . . . . . . . . .
MHAEvents::patchbay_t< receiver_t > Class Template Reference . . .
MHAFilter::adapt_filter_t Class Reference . . . . . . . . . . . . . . . .
MHAFilter::blockprocessing_polyphase_resampling_t Class Reference
MHAFilter::complex_bandpass_t Class Reference . . . . . . . . . . . .
MHAFilter::diff_t Class Reference . . . . . . . . . . . . . . . . . . . . .
MHAFilter::fftfilter_t Class Reference . . . . . . . . . . . . . . . . . . .
MHAFilter::fftfilterbank_t Class Reference . . . . . . . . . . . . . . . .
MHAFilter::filter_t Class Reference . . . . . . . . . . . . . . . . . . . .
MHAFilter::gamma_flt_t Class Reference . . . . . . . . . . . . . . . . .
MHAFilter::iir_filter_t Class Reference . . . . . . . . . . . . . . . . . . .
MHAFilter::iir_ord1_real_t Class Reference . . . . . . . . . . . . . . . .

© 2005-2018 HörTech gGmbH, Oldenburg

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101
102
103
105
110
113
113
114
116
118
118
119
119
120
122
122
123
123
124
127
127
132
132
135
137
137
139
140
141
143
143
144
149
150
150
152
153
154
155
156
156
157
157
159
160
160
163
165
167
168
170

vi

CONTENTS

4.64 MHAFilter::o1_ar_filter_t Class Reference . . . . . . . . . . . .
4.65 MHAFilter::o1flt_lowpass_t Class Reference . . . . . . . . . . .
4.66 MHAFilter::o1flt_maxtrack_t Class Reference . . . . . . . . . .
4.67 MHAFilter::o1flt_mintrack_t Class Reference . . . . . . . . . . .
4.68 MHAFilter::partitioned_convolution_t Class Reference . . . . . .
4.69 MHAFilter::partitioned_convolution_t::index_t Struct Reference .
4.70 MHAFilter::polyphase_resampling_t Class Reference . . . . . .
4.71 MHAFilter::resampling_filter_t Class Reference . . . . . . . . .
4.72 MHAFilter::smoothspec_t Class Reference . . . . . . . . . . . .
4.73 MHAFilter::transfer_function_t Struct Reference . . . . . . . . .
4.74 MHAFilter::transfer_matrix_t Struct Reference . . . . . . . . . .
4.75 MHAIOJack::io_jack_t Class Reference . . . . . . . . . . . . . .
4.76 MHAJack::client_avg_t Class Reference . . . . . . . . . . . . .
4.77 MHAJack::client_noncont_t Class Reference . . . . . . . . . . .
4.78 MHAJack::client_t Class Reference . . . . . . . . . . . . . . . .
4.79 MHAJack::port_t Class Reference . . . . . . . . . . . . . . . . .
4.80 MHAMultiSrc::base_t Class Reference . . . . . . . . . . . . . .
4.81 MHAOvlFilter::fftfb_t Class Reference . . . . . . . . . . . . . . .
4.82 MHAOvlFilter::fftfb_vars_t Class Reference . . . . . . . . . . . .
4.83 MHAOvlFilter::fspacing_t Class Reference . . . . . . . . . . . .
4.84 MHAOvlFilter::overlap_save_filterbank_t Class Reference . . .
4.85 MHAParser::base_t Class Reference . . . . . . . . . . . . . . .
4.86 MHAParser::bool_mon_t Class Reference . . . . . . . . . . . .
4.87 MHAParser::bool_t Class Reference . . . . . . . . . . . . . . .
4.88 MHAParser::commit_t< receiver_t > Class Template Reference
4.89 MHAParser::complex_mon_t Class Reference . . . . . . . . . .
4.90 MHAParser::complex_t Class Reference . . . . . . . . . . . . .
4.91 MHAParser::float_mon_t Class Reference . . . . . . . . . . . .
4.92 MHAParser::float_t Class Reference . . . . . . . . . . . . . . .
4.93 MHAParser::int_mon_t Class Reference . . . . . . . . . . . . .
4.94 MHAParser::int_t Class Reference . . . . . . . . . . . . . . . . .
4.95 MHAParser::keyword_list_t Class Reference . . . . . . . . . . .
4.96 MHAParser::kw_t Class Reference . . . . . . . . . . . . . . . .
4.97 MHAParser::mcomplex_mon_t Class Reference . . . . . . . . .
4.98 MHAParser::mcomplex_t Class Reference . . . . . . . . . . . .
4.99 MHAParser::mfloat_mon_t Class Reference . . . . . . . . . . .
4.100 MHAParser::mfloat_t Class Reference . . . . . . . . . . . . . .
4.101 MHAParser::mhapluginloader_t Class Reference . . . . . . . .
4.102 MHAParser::monitor_t Class Reference . . . . . . . . . . . . . .
4.103 MHAParser::parser_t Class Reference . . . . . . . . . . . . . .
4.104 MHAParser::range_var_t Class Reference . . . . . . . . . . . .
4.105 MHAParser::string_mon_t Class Reference . . . . . . . . . . .
4.106 MHAParser::string_t Class Reference . . . . . . . . . . . . . . .
4.107 MHAParser::variable_t Class Reference . . . . . . . . . . . . .
4.108 MHAParser::vcomplex_mon_t Class Reference . . . . . . . . .
4.109 MHAParser::vcomplex_t Class Reference . . . . . . . . . . . .
4.110 MHAParser::vfloat_mon_t Class Reference . . . . . . . . . . . .
4.111 MHAParser::vfloat_t Class Reference . . . . . . . . . . . . . . .
4.112 MHAParser::vint_mon_t Class Reference . . . . . . . . . . . . .
4.113 MHAParser::vint_t Class Reference . . . . . . . . . . . . . . . .
4.114 MHAParser::vstring_mon_t Class Reference . . . . . . . . . . .

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© 2005-2018 HörTech gGmbH, Oldenburg

CONTENTS

vii

4.115 MHAParser::vstring_t Class Reference . . . . . . . . . . . . . . . .
4.116 MHAParser::window_t Class Reference . . . . . . . . . . . . . . . .
4.117 MHAPlugin::config_t< runtime_cfg_t > Class Template Reference .
4.118 MHAPlugin::plugin_t< runtime_cfg_t > Class Template Reference .
4.119 mhaserver_t Class Reference . . . . . . . . . . . . . . . . . . . . .
4.120 MHASignal::async_rmslevel_t Class Reference . . . . . . . . . . .
4.121 MHASignal::delay_t Class Reference . . . . . . . . . . . . . . . . .
4.122 MHASignal::delay_wave_t Class Reference . . . . . . . . . . . . .
4.123 MHASignal::doublebuffer_t Class Reference . . . . . . . . . . . . .
4.124 MHASignal::hilbert_t Class Reference . . . . . . . . . . . . . . . .
4.125 MHASignal::loop_wavefragment_t Class Reference . . . . . . . . .
4.126 MHASignal::matrix_t Class Reference . . . . . . . . . . . . . . . . .
4.127 MHASignal::minphase_t Class Reference . . . . . . . . . . . . . .
4.128 MHASignal::quantizer_t Class Reference . . . . . . . . . . . . . . .
4.129 MHASignal::ringbuffer_t Class Reference . . . . . . . . . . . . . . .
4.130 MHASignal::schroeder_t Class Reference . . . . . . . . . . . . . .
4.131 MHASignal::spectrum_t Class Reference . . . . . . . . . . . . . . .
4.132 MHASignal::subsample_delay_t Class Reference . . . . . . . . . .
4.133 MHASignal::uint_vector_t Class Reference . . . . . . . . . . . . . .
4.134 MHASignal::waveform_t Class Reference . . . . . . . . . . . . . . .
4.135 MHATableLookup::xy_table_t Class Reference . . . . . . . . . . . .
4.136 MHAWindow::bartlett_t Class Reference . . . . . . . . . . . . . . .
4.137 MHAWindow::base_t Class Reference . . . . . . . . . . . . . . . .
4.138 MHAWindow::blackman_t Class Reference . . . . . . . . . . . . . .
4.139 MHAWindow::fun_t Class Reference . . . . . . . . . . . . . . . . .
4.140 MHAWindow::hamming_t Class Reference . . . . . . . . . . . . . .
4.141 MHAWindow::hanning_t Class Reference . . . . . . . . . . . . . .
4.142 MHAWindow::rect_t Class Reference . . . . . . . . . . . . . . . . .
4.143 MHAWindow::user_t Class Reference . . . . . . . . . . . . . . . . .
4.144 PluginLoader::fourway_processor_t Class Reference . . . . . . . .
5 File Documentation
5.1 mha.h File Reference . . . . . . . .
5.2 mha_algo_comm.h File Reference
5.3 mha_defs.h File Reference . . . . .
5.4 mha_error.cpp File Reference . . .
5.5 mha_filter.hh File Reference . . . .
5.6 mha_parser.hh File Reference . . .
5.7 mha_plugin.hh File Reference . . .
5.8 mha_signal.hh File Reference . . .
5.9 mha_tablelookup.hh File Reference
Index

© 2005-2018 HörTech gGmbH, Oldenburg

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1 Overview

1

1

Overview

The HörTech Open Master Hearing Aid (openMHA), is a development and evaluation software
platform that is able to execute hearing aid signal processing in real-time on standard computing
hardware with a low delay between sound input and output.

1.1

Structure

The openMHA can be split into four major components :
• The openMHA command line application (MHA) (p. 33)
• Signal processing plugins (p. 6)
• Audio input-output (IO) plugins (see io_file_t (p. 100), MHAIOJack (p. 71), io_parser_t
(p. 102), io_tcp_parser_t (p. 105))
• The openMHA toolbox library (p. 34)

control applications
(e.g., Octave)
openMHA
libopenmha

plugins

MHA

IO

audio backend
(Jack, File, TCP)

Figure 1 openMHA structure

The openMHA command line application (MHA) (p. 33) acts as a plugin host. It can load
signal processing plugins as well as audio input-output (IO) plugins. Additionally, it provides
the command line configuration interface and a TCP/IP based configuration interface. Several
IO plugins exist: For real-time signal processing, commonly the openMHA MHAIOJack (p. 71)
plugin (see plugins' manual) is used, which provides an interface to the Jack Audio Connection
Kit (JACK). Other IO plugins provide audio file access or TCP/IP-based processing.
openMHA plugins (p. 6) provide the audio signal processing capabilities and audio signal handling. Typically, one openMHA plugin implements one specific algorithm. The complete virtual
hearing aid signal processing can be achieved by a combination of several openMHA plugins.
© 2005-2018 HörTech gGmbH, Oldenburg

2

1.2

CONTENTS

Platform Services and Conventions

The openMHA platform offers some services and conventions to algorithms implemented in
plugins, that make it especially well suited to develop hearing aid algorithms, while still supporting general-purpose signal processing.

1.2.1

Audio Signal Domains

As in most other plugin hosts, the audio signal in the openMHA is processed in audio chunks.
However, plugins are not restricted to propagate audio signal as blocks of audio samples in the
time domain another option is to propagate the audio signal in the short time Fourier transform
(STFT) domain, i.e. as spectra of blocks of audio signal, so that not every plugin has to perform
its own STFT analysis and synthesis. Since STFT analysis and re-synthesis of acceptable
audio quality always introduces an algorithmic delay, sharing STFT data is a necessity for a
hearing aid signal processing platform, because the overall delay of the complete processing
has to be as short as possible.
Similar to some other platforms, the openMHA allows also arbitrary data to be exchanged
between plugins through a mechanism called algorithm communication variables (p. 27) or
short "AC vars". This mechanism is commonly used to share data such as filter coefficients or
filter states.

1.2.2

Real-Time Safe Complex Configuration Changes

Hearing aid algorithms in the openMHA can export configuration settings that may be changed
by the user at run time.
To ensure real-time safe signal processing, the audio processing will normally be done in a
signal processing thread with real-time priority, while user interaction with configuration parameters would be performed in a configuration thread with normal priority, so that the audio
processing does not get interrupted by configuration tasks. Two types of problems may occur
when the user is changing parameters in such a setup:
• The change of a simple parameter exposed to the user may cause an involved recalculation of internal runtime parameters that the algorithm actually uses in processing. The
duration required to perform this recalculation may be a significant portion of (or take even
longer than) the time available to process one block of audio signal. In hearing aid usage,
it is not acceptable to halt audio processing for the duration that the recalculation may
require.
• If the user needs to change multiple parameters to reach a desired configuration state
of an algorithm from the original configuration state, then it may not be acceptable that
processing is performed while some of the parameters have already been changed while
others still retain their original values. It is also not acceptable to interrupt signal processing until all pending configuration changes have been performed.
© 2005-2018 HörTech gGmbH, Oldenburg

1.2

Platform Services and Conventions

3

The openMHA provides a mechanism in its toolbox library to enable real-time safe configuration
changes in openMHA plugins:
Basically, existing runtime configurations are used in the processing thread until the work of
creating an updated runtime configuration has been completed in the configuration thread.
In hearing aids, it is more acceptable to continue to use an outdated configuration for a few
more milliseconds than blocking all processing.
The openMHA toolbox library provides an easy-to-use mechanism to integrate real-time safe
runtime configuration updates into every plugin.

1.2.3

Plugins can Themselves Host Other Plugins

An openMHA plugin can itself act as a plugin host. This allows to combine analysis and resynthesis methods in a single plugin. We call plugins that can themselves load other plugins
“bridge plugins'' in the openMHA.
When such a bridge plugin is then called by the openMHA to process one block of signal, it
will first perform its analysis, then invoke (as a function call) the signal processing in the loaded
plugin to process the block of signal in the analysis domain, wait to receive a processed block of
signal in the analysis domain back from the loaded plugin when the signal processing function
call to that plugin returns, then perform the re-synthesis transform, and finally return the block
of processed signal in the original domain back to the caller of the bridge plugin.

1.2.4

Central Calibration

The purpose of hearing aid signal processing is to enhance the sound for hearing impaired
listeners. Hearing impairment generally means that people suffering from it have increased
hearing thresholds, i.e. soft sounds that are audible for normal hearing listeners may be imperceptible for hearing impaired listeners. To provide accurate signal enhancement for hearing
impaired people, hearing aid signal processing algorithms have to be able to determine the
absolute physical sound pressure level corresponding to a digital signal given to any openM←HA plugin for processing. Inside the openMHA, we achieve this with the following convention:
The single-precision floating point time-domain sound signal samples, that are processed inside the openMHA plugins in blocks of short durations, have the physical pressure unit Pascal
( 1Pa = 1N/m2 ). With this convention in place, all plugins can determine the absolute physical sound pressure level from the sound samples that they process. A derived convention is
employed in the spectral domain for STFT signals. Due to the dependency of the calibration
on the hardware used, it is the responsibility of the user of the openMHA to perform calibration
measurements and adapt the openMHA settings to make sure that this calibration convention is
met. We provide the plugin transducers which can be configured to perform the necessary
signal adjustments.
© 2005-2018 HörTech gGmbH, Oldenburg

4

2
2.1

CONTENTS

Module Documentation
Concept of Variables and Data Exchange in the openMHA

Accessibility of configuration variables and data exchange between plugins (processing blocks)
are an important issue in the openMHA.
In general, variable types in the openMHA are distinguished by their different access methods.
The variable types in the openMHA are:
• Configuration variables : Read and write accesses are possible through the openM←HA configuration language interface. Configuration variables are implemented as C++
classes with a public data member of the underlying C type. Configuration variables
can be read and modified from “outside'' using the configuration language. The plugin
which provides the configuration variable can use the exposed data member directly. All
accesses through the openMHA configuration language are checked for data type, valid
range, and access restrictions.
• Monitor variables : Read access is possible through the openMHA configuration language. Write access is only possible from the C++ code. Internally, monitor variables
have a similar C++ class interface as configuration variables.
• AC variables (algorithm communication variables (p. 27)): Any C or C++ data structure can be shared within an openMHA chain. Access management and name space
is realised in openMHA chain plugin ('mhachain'). AC variables are not available to the
openMHA configuration language interface, although a read-only converter plugin acmon
is available.
• Runtime configuration : Algorithms usually derive more parameters (runtime configuration) from the openMHA configuration language variables. When a configuration variable
changes through configuration language write access, then the runtime configuration has
to be recomputed. Plugin developers are encouraged to encapsulate the runtime configuration in a C++ class, which recomputes the runtime configuration from configuration
variables in the constructor. The openMHA supports lock-free and thread-safe replacement of the runtime configuration instance (see example5.cpp (p. 20) and references
therein).
Configuration language

Plugin specific

Chain specific

variables

runtime configuation
(e.g. C++ class)

algorithm communication
(AC variables)

monitors

Figure 2 Variable types in the openMHA

The C++ data types are shown in the figure below. These variables can be accessed via the
openMHA host application using the openMHA configuration language. For more details see
'Application engineers' manual'.
© 2005-2018 HörTech gGmbH, Oldenburg

2.1

Concept of Variables and Data Exchange in the openMHA

5

MHAParser elements
Monitors

Variables

Numeric monitors

Numeric variables

int_mon_t

int_t

vint_mon_t

vint_t

float_mon_t

float_t

vfloat_mon_t

vfloat_t

mfloat_mon_t

mfloat_t

complex_mon_t

complex_t

vcomplex_mon_t

vcompelx_t

string_mon_t

string_t

vstring_mon_t

vstring_t
kw_t
bool_t

Figure 3 MHAParser elements

© 2005-2018 HörTech gGmbH, Oldenburg

parser_t

6

2.2

CONTENTS

The openMHA Plugins (programming interface)

An openMHA plugin is the signal processing unit, usually an algorithm.

Classes
• class MHAPlugin::plugin_t< runtime_cfg_t >
The template class for C++ openMHA plugins.

Macros
• #define MHAPLUGIN_CALLBACKS_PREFIX(prefix, classname, indom, outdom)
C++ wrapper macro for the plugin interface.

• #define MHAPLUGIN_CALLBACKS(plugname, classname, indom, outdom) MHAPLU←GIN_CALLBACKS_PREFIX(MHA_STATIC_ ## plugname ## _,classname,indom,outdom)
C++ wrapper macro for the plugin interface.

• #define MHAPLUGIN_DOCUMENTATION(plugname, cat, doc) MHAPLUGIN_DOCU←MENTATION_PREFIX(MHA_STATIC_ ## plugname ## _,cat,doc)
Wrapper macro for the plugin documentation interface.

2.2.1

Detailed Description

openMHA plugins can be combined into processing chains. One of the configured chains can
be selected for output which allows direct comparison of single algorithms or complex signal
processing configurations. Algorithms within one chain can communicate with each other by
sharing some of their variables, see section Communication between algorithms (p. 27).
The openMHA plugins can use the openMHA configuration language for their configuration.
If they do so, the configuration can be changed through the framework even at run time. A
description of this language can be found in section The openMHA configuration language
(p. 33). If the algorithms should make use of the openMHA configuration language, they need
to be written in C++ rather than pure C.
In the openMHA package a set of example plugins is included. These examples are the base
of a step by step tutorial on how to write an openMHA plugin. See section Writing openMHA
Plugins. A step-by-step tutorial (p. 10) for detailes.
openMHA plugins communicate with the openMHA using a simple ANSI-C interface. This
way it is easy to mix plugins compiled with different C++ compilers. For convenience, we
provide C++ classes which can be connected to the C++ interface. We strongly recommend
the usage of these C++ wrappers. They include out-of-the box support exporting variables to
the configuration interface and for thread safe configuration update.
The openMHA C++ plugin interface consists of a few number of method prototypes:
The output domain (spectrum or waveform) of an openMHA plugin will typically be the same as
the input domain:
© 2005-2018 HörTech gGmbH, Oldenburg

2.2

The openMHA Plugins (programming interface)

7

• mha_wave_t (p. 154) ∗ process(mha_wave_t (p. 154) ∗): pure waveform processing
• mha_spec_t (p. 141) ∗ process(mha_spec_t (p. 141) ∗): pure spectral processing

But it is also possible to implement domain transformations (from the time domain into spectrum
or vice versa). The corresponding method signatures are:

• mha_spec_t (p. 141) ∗ process(mha_wave_t (p. 154) ∗): Domain transformation from
waveform to spectrum
• mha_wave_t (p. 154) ∗ process(mha_spec_t (p. 141) ∗): Domain transformation from
spectrum to waveform

For preparation and release of a plugin, the methods

• void prepare(mhaconfig_t (p. 155) &) and
• void release(void)

have to be implemented. The openMHA will call the process() method only ater the prepare method has returned and before release() is invoked. It is guarantteed by the open←MHA framework that signal processing is performed only between calls of prepare() and
release(). Each call of prepare() is followed by a call of release() (after some optional
signal processing).
For configuration purposes, the plugin class has to export a method called parse() which
implements the openMHA configuration language. We strongly recommend that you do not
implement this method yourself, but by inheriting from the class MHAParser::parser_t (p. 220)
from the openMHA toolbox, directly or indirectly (inheriting from a class that itself inherits from
MHAParser::parser_t (p. 220)).

2.2.2

Connecting the C++ class with the C Interface

A C++ class which provides the appropriate methods can be used as an openMHA Plugin by
connecting it to the C interface using the MHAPLUGIN_CALLBACKS (p. 8) macro.
The openMHA Toolbox library provides a base class MHAPlugin::plugin_t (p. 238) (a
template class) which can be used as the base class for a plugin class. This base class implements some necessary features for openMHA plugin developers like integration into the
openMHA configuration language environment (it inherits from MHAParser::parser_t (p. 220))
and thread-safe runtime configuration update.
© 2005-2018 HörTech gGmbH, Oldenburg

8

2.2.3

CONTENTS

Error reporting

When your plugin detects a situation that it cannot handle, like input signal of the wrong signal
domain at preparation time, unsupported number of input channels at preparation time, unsupported combinations of values in the plugin's variables during configuration, it should throw a
C++ exception. The exception should be of type MHAError. Exceptions of this type are caught
by the MHAPLUGIN_CALLBACKS (p. 8) macro for further error Reporting.
Throwing exceptions in response to unsupported configuration changes does not stop the signal processing. The openMHA configuration language parser will restore the previous value
of that variable and report an error to the configurator, while the signal processing continues.
Throwing exceptions from the signal processing thread will terminate the signal processing.
Therefore, you should generally avoid throwing exceptions from the process method. Only do
this if you detected a defect in your plugin, and then you should include enough information in
the error message to be able to fix the defect.

2.2.4

Contents of the openMHA Plugin programming interface

2.2.5

Macro Definition Documentation

2.2.5.1

#define MHAPLUGIN_CALLBACKS_PREFIX( prefix, classname, indom, outdom )

Parameters
classname

The name of the plugin class

indom

Input domain (wave or spec)

outdom

Output domain (wave or spec)

This macro defines all required openMHA Plugin interface functions and passes calls of these
functions to the corresponding member functions of the class ‘classname'. The parameters
‘indom' and ‘outdom' specify the input and output domain of the processing method. The
MHAInit() and MHADestroy() functions will create or destroy an instance of the class. The
approriate member functions have to be defined in the class. It is suggested to make usage of
the MHAPlugin::plugin_t (p. 238) template class. Exceptions of type MHA_Error (p. 132) are
caught and transformed into apropriate error codes with their corresponding error messages.
2.2.5.2

#define MHAPLUGIN_CALLBACKS( plugname, classname, indom, outdom
) MHAPLUGIN_CALLBACKS_PREFIX(MHA_STATIC_ ## plugname ##
_,classname,indom,outdom)

Parameters
plugname

The file name of the plugin without the .so or .dll extension

classname

The name of the plugin class

indom

Input domain (wave or spec)

outdom

Output domain (wave or spec)
© 2005-2018 HörTech gGmbH, Oldenburg

2.2

The openMHA Plugins (programming interface)

9

This macro defines all required openMHA Plugin interface functions and passes calls of these
functions to the corresponding member functions of the class ‘classname'. The parameters
‘indom' and ‘outdom' specify the input and output domain of the processing method. The MHA←Init() and MHADestroy() functions will create or destroy an instance of the class. The approriate
member functions have to be defined in the class. It is suggested to make usage of the MH←APlugin::plugin_t (p. 238) template class. Exceptions of type MHA_Error (p. 132) are caught
and transformed into apropriate error codes with their corresponding error messages.
2.2.5.3

#define MHAPLUGIN_DOCUMENTATION( plugname, cat, doc
) MHAPLUGIN_DOCUMENTATION_PREFIX(MHA_STATIC_ ## plugname ## _,cat,doc)

Parameters
plugin

The file name of the plugin without the .so or .dll extension

cat

Space separated list of categories to which belong the plugin (as const char∗)

doc

Documentation of the plugin (as const char∗)

This macro defines the openMHA Plugin interface function for the documentation. The categories can be any space seperated list of category names. An empty string will categorize the
plugin in the category 'other'.
The documentation should contain a description of the plugin including a description of the
underlying models, and a paragraph containing hints for usage. The text should be LaTeX
compatible (e.g., avoid or quote underscores in the text part); equations should be formatted
as LaTeX.

© 2005-2018 HörTech gGmbH, Oldenburg

10

2.3

CONTENTS

Writing openMHA Plugins. A step-by-step tutorial

A step-by-step tutorial on writing openMHA plugins.
openMHA contains a small number of example plugins as C++ source code. They are meant to
help developers in understanding the concepts of openMHA plugin programming starting from
the simplest example and increasing in complexity. This tutorial explains the basic parts of the
example files.

2.3.1

example1.cpp

The example plugin file example1.cpp demonstrates the easiest way to implement an open←MHA Plugin. It attenuates the sound signal in the first channel by multiplying the sound samples
with a factor. The plugin class MHAPlugin::plugin_t (p. 238) exports several methods, but only
two of them need a non-empty implementation: prepare() method is a pure virtual function
and process() is called when signal processing starts.
#include "mha_plugin.hh"
class example1_t : public MHAPlugin::plugin_t {
public:
example1_t(algo_comm_t & ac,
const std::string & chain_name,
const std::string & algo_name)
: MHAPlugin::plugin_t("",ac)
{/* Do nothing in constructor */}
void release(void)
{/* Do nothing in release */}

Every plugin implementation should include the 'mha_plugin.hh (p. 296)' header file. C++
helper classes for plugin development are declared in this header file, and most header files
needed for plugin development are included by mha_plugin.hh (p. 296).
The class plugin1_t inherits from the class MHAPlugin::plugin_t (p. 238), which then inherits from MHAParser::parser_t (p. 220) – the configuration language interface in the method
"parse". Our plugin class therefore exports the working "parse" method inherited from MHA←Parser::parser_t (p. 220), and the plugin is visible in the openMHA configuration tree.
The constructor has to accept 3 parameters of correct types. In this simple example, we do not
make use of them.
The release() method is used to free resources after signal processing. In this simple example, we do not allocate resources, so there is no need to free them.
2.3.1.1

The prepare method

void prepare(mhaconfig_t & signal_info)
{
if (signal_info.domain != MHA_WAVEFORM)
throw MHA_Error(__FILE__, __LINE__,
"This plugin can only process waveform signals.");
if (signal_info.channels < 1)
throw MHA_Error(__FILE__,__LINE__,
"This plugin requires at least one input channel.");
}

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Parameters
signal_info

Contains information about the input signal's parameters, see mhaconfig_t
(p. 155).

The prepare() method of the plugin is called before the signal processing starts, when the
input signal parameters like domain, number of channels, frames per block, and sampling rate
are known. The prepare() method can check these values and raise an exception if the
plugin cannot cope with them, as is done here. The plugin can also change these values if the
signal processing performed in the plugin results in an output signal with different parameters.
This plugin does not change the signal's parameters, therefore they are not modified here.
2.3.1.2

The signal processing method

mha_wave_t * process(mha_wave_t * signal)
{
unsigned int channel = 0; // channels and frames counting starts with 0
float factor = 0.1f;
unsigned int frame;
// Scale channel number "channel" by "factor":
for(frame = 0; frame < signal->num_frames; frame++) {
// Waveform channels are stored interleaved.
signal->buf[signal->num_channels * frame + channel] *= factor;
}
// Algorithms may process data in-place and return the input signal
// structure as their output signal:
return signal;
}
};

Parameters
signal

Pointer to the input signal structure mha_wave_t (p. 154).

Returns
Pointer to the output signal structure. The input signal structure may be reused if the
signal has the same domain and dimensions.
The plugin works with time domain input signal (indicated by the data type mha_wave_t (p. 154)
of the process method's parameter). It scales the first channel by a factor of 0.1. The output
signal reuses the structure that previously contained the input signal (in-place processing).
2.3.1.3

Connecting the C++ class with the C plugin interface

Plugins have to export C functions as their interface (to avoid C++ name-mangling issues and
other incompatibilities when mixing plugins compiled with different C++ compilers).
MHAPLUGIN_CALLBACKS(example1,example1_t,wave,wave)

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This macro takes care of accessing the C++ class from the C functions required as the plugin's
interface. It implements the C funtions and calls the corresponding C++ instance methods.
Plugin classes should be derived from the template class MHAPlugin::plugin_t (p. 238) to be
compatible with the C interface wrapper.
This macro also catches C++ exceptions of type MHA_Error (p. 132), when raised in the methods of the plugin class, and reports the error using an error flag as the return value of the
underlying C function. It is therefore important to note that only C++ exceptions of type MH←A_Error (p. 132) may be raised by your plugin. If your code uses different Exception classes,
you will have to catch them yourself before control leaves your plugin class, and maybe report
the error by throwing an instance of MHA_Error (p. 132). This is important, because: (1) C++
exceptions cannot cross the plugin interface, which is in C, and (2) there is no error handling
code for your exception classes in the openMHA framework anyways.

2.3.2

example2.cpp

This is another simple example of openMHA plugin written in C++. This plugin also scales one
channel of the input signal, working in the time domain. The scale factor and which channel to
scale (index number) are made accessible to the configuration language.
The algorithm is again implemented as a C++ class.

class example2_t : public MHAPlugin::plugin_t {
MHAParser::int_t scale_ch;
MHAParser::float_t factor;
public:
example2_t(algo_comm_t & ac,
const std::string & chain_name,
const std::string & algo_name);
void prepare(mhaconfig_t & signal_info);
void release(void);
mha_wave_t * process(mha_wave_t * signal);
};

Parameters
scale_ch
factor

– the channel number to be scaled
– the scale factor of the scaling.

This class again inherits from the template class MHAPlugin::plugin_t (p. 238) for intergration
with the openMHA configuration language. The two data members serve as externally visible
configuration variables. All methods of this class have a non-empty implementation.
2.3.2.1

Constructor

example2_t::example2_t(algo_comm_t & ac,
const std::string & chain_name,

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const std::string & algo_name)
: MHAPlugin::plugin_t("This plugin multiplies the sound signal"
" in one audio channel by a factor",ac),
scale_ch("Index of audio channel to scale. Indices start from 0.",
"0",
"[0,["),
factor("The scaling factor that is applied to the selected channel.",
"0.1",
"[0,[")
{
insert_item("channel", &scale_ch);
insert_item("factor", &factor);
}

The constructor invokes the superclass constructor with a string parameter. This string parameter serves as the help text that describes the functionality of the plugin. The constructor
registers configuration variables with the openMHA configuration tree and sets their default values and permitted ranges. The minimum permitted value for both variables is zero, and there is
no maximum limit (apart from the limitations of the underlying C data type). The configuration
variables have to be registered with the parser node instance using the MHAParser::parser←_t::insert_item (p. 222) method.
2.3.2.2

The prepare method

void example2_t::prepare(mhaconfig_t & signal_info)
{
if (signal_info.domain != MHA_WAVEFORM)
throw MHA_Error(__FILE__, __LINE__,
"This plugin can only process waveform signals.");
// The user may have configured scale_ch before prepare is called.
// Check that the configured channel is present in the input signal.
if (signal_info.channels <= unsigned(scale_ch.data))
throw MHA_Error(__FILE__,__LINE__,
"This plugin requires at least %d input channels.",
scale_ch.data + 1);
// Adjust the range of the channel configuration variable so that it
// cannot be set to an out-of-range value during processing.
using MHAParser::StrCnv::val2str;
scale_ch.set_range("[0," + val2str(int(signal_info.channels)) + "[");
}

Parameters
signal_info

– contains information about the input signal's parameters, see mhaconfig_t
(p. 155).

The user may have changed the configuration variables before preparing the openMHA plugin.
A consequence of this is that it is not sufficient any more to check if the input signal has at least
1 audio channel.
Instead, this prepare method checks that the input signal has enough channels so that the current value of scale_ch.data is a valid channel index, i.e. 0 ≤ scale_ch.data < signal←_info.channels. The prepare method does not have to check that 0 ≤ scale_ch.data,
since this is guaranteed by the valid range setting of the configuration variable.
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The prepare method then modifies the valid range of the scale_ch variable, it modifies the upper bound so that the user cannot set the variable to a channel index higher than the available
channels. Setting the range is done using a string parameter. The prepare method contatenates a string of the form "[0,n[". n is the number of channels in the input signal, and is used
here as an exclusive upper boundary. To convert the number of channels into a string, a helper
function for string conversion from the openMHA Toolbox is used. This function is overloaded
and works for several data types.
It is safe to assume that the value of configuration variables does not change while the prepare method executes, since openMHA preparation is triggered from a configuration language
command, and the openMHA configuration language parser is busy and cannot accept other
commands until all openMHA plugins are prepared (or one of them stops the process by raising
an exception). As we will see later in this tutorial, the same assumption cannot be made for the
process method.
2.3.2.3

The release method

void example2_t::release(void)
{
scale_ch.set_range("[0,[");
}

The release method should undo the state changes that were performed by the prepare
method. In this example, the prepare method has reduced the valid range of the scale_←ch, so that only valid channels could be selected during signal processing.
The release method reverts this change by setting the valid range back to its original value,
"[0,[".
2.3.2.4

The signal processing method

mha_wave_t * example2_t::process(mha_wave_t * signal)
{
unsigned int frame;
for(frame = 0; frame < signal->num_frames; frame++)
value(signal,frame,scale_ch.data) *= factor.data;
return signal;
}

The processing function uses the current values of the configuration variables to scale every
frame in the selected audio channel.
Note that the value of each configuration variable can change while the processing method
executes, since the process method usually executes in a different thread than the configuration
interface.
For this simple plugin, this is not a problem, but for more advanced plugins, it has to be taken
into consideration. The next section takes a closer look at the problem.
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Consistency
Assume that one thread reads the value stored in a variable while another thread writes a new
value to that variable concurrently. In this case, you may have a consistency problem. You
would perhaps expect that the value retrieved from the variable either (a) the old value, or (b)
the new value, but not (c) something else. Yet generally case (c) is a possibility.
Fortunately, for some data types on PC systems, case (c) cannot happen. These are 32bit
wide data types with a 4-byte alignment. Therefore, the values in MHAParser::int_t (p. 211)
and MHAParser::float_t (p. 208) are always consistent, but this is not the case for vectors,
strings, or complex values. With these, you can get a mixture of the bit patterns of old and new
values, or you can even cause a memory access violation in case a vector or string grows and
has to be reallocated to a different memory address.
There is also a consistency problem if you take the combination of two "safe" datatypes. The
openMHA provides a mechanism that can cope with these types of problems. This thread-safe
runtime configuration update mechanism is introduced in example 5.
2.3.3

example3.cpp

This example introduces the openMHA Event mechanism. Plugins that provide configuration
variable can receive a callback from the parser base class when a configuration variable is
accessed through the configuration language interface.
The third example performes the same processing as before, but now only even channel indices
are permitted when selecting the audio channel to scale. This restriction cannot be ensured by
setting the range of the channel index configuration variable. Instead, the event mechanism of
openMHA configuration variables is used. Configuration variables emit 4 different events, and
your plugin can connect callback methods that are called when the events are triggered. These
events are:
writeaccess
• triggered on write access to a configuration variable.
valuechanged
• triggered when write access to a configuration variable actually changes the value of this
variable.
readaccess
• triggered after the value of the configuration variable has been read.
prereadaccess
• triggered before the value of a configuration variable is read, i.e. the value of the requested variable can be changed by the callback to implement computation on demand.
All of these callbacks are executed in the configuration thread. Therefore, the callback implementation does not have to be realtime-safe. No other updates of configuration language variables through the configuration language can happen in parallel, but your processing method
can execute in parallel and may change values.
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2.3.3.1

CONTENTS

Data member declarations

class example3_t : public MHAPlugin::plugin_t {
MHAParser::int_t scale_ch;
MHAParser::float_t factor;
MHAParser::int_mon_t prepared;
MHAEvents::patchbay_t patchbay;

This plugin exposes another configuration variable, "prepared", that keeps track of the prepared state of the plugin. This is a read-only (monitor) integer variable, i.e. its value can only
be changed by your plugin's C++ code. When using the configuration language interface, the
value of this variable can only be read, but not changed.
The patchbay member is an instance of a connector class that connects event sources with
callbacks.

2.3.3.2

Method declarations

/* Callbacks triggered by Events */
void on_scale_ch_writeaccess();
void on_scale_ch_valuechanged();
void on_scale_ch_readaccess();
void on_prereadaccess();
public:
example3_t(algo_comm_t & ac,
const std::string & chain_name,
const std::string & algo_name);
void prepare(mhaconfig_t & signal_info);
void release(void);
mha_wave_t * process(mha_wave_t * signal);
};

This plugin exposes 4 callback methods that are triggered by events. Multiple events (from the
same or different configuration variables) can be connected to the same callback method, if
desired.
This example plugin uses the valuechanged event to check that the scale_ch configuration
variable is only set to valid values.
The other callbacks only cause log messages to stdout, but the comments in the logging callbacks give a hint when listening on the events would be useful.
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2.3.3.3

17

Example 3 constructor

example3_t::example3_t(algo_comm_t & ac,
const std::string & chain_name,
const std::string & algo_name)
: MHAPlugin::plugin_t("This plugin multiplies the sound signal"
" in one audio channel by a factor",ac),
scale_ch("Index of audio channel to scale. Indices start from 0."
" Only channels with even indices may be scaled.",
"0",
"[0,["),
factor("The scaling factor that is applied to the selected channel.",
"0.1",
"[0,["),
prepared("State of this plugin: 0 = unprepared, 1 = prepared")
{
insert_item("channel", &scale_ch);
insert_item("factor", &factor);
prepared.data = 0;
insert_item("prepared", &prepared);
patchbay.connect(&scale_ch.writeaccess, this,
&example3_t::on_scale_ch_writeaccess);
patchbay.connect(&scale_ch.valuechanged, this,
&example3_t::on_scale_ch_valuechanged);
patchbay.connect(&scale_ch.readaccess, this,
&example3_t::on_scale_ch_readaccess);
patchbay.connect(&scale_ch.prereadaccess, this,
&example3_t::on_prereadaccess);
patchbay.connect(&factor.prereadaccess, this,
&example3_t::on_prereadaccess);
patchbay.connect(&prepared.prereadaccess, this,
&example3_t::on_prereadaccess);
}

The constructor of monitor variables does not take a parameter for setting the initial value.
The single parameter here is the help text describing the contents of the read-only variable.
If the initial value should differ from 0, then the .data member of the configuration variable
has to be set to the initial value in the plugin constructor's body explicitly, as is done here for
demonstration although the initial value of this monitor variable is 0.
Events and callback methods are then connected using the patchbay member variable.
2.3.3.4

The prepare method

void example3_t::prepare(mhaconfig_t & signal_info)
{
if (signal_info.domain != MHA_WAVEFORM)
throw MHA_Error(__FILE__, __LINE__,
"This plugin can only process waveform signals.");
// The user may have configured scale_ch before prepare is called.
// Check that the configured channel is present in the input signal.
if (signal_info.channels <= unsigned(scale_ch.data))
throw MHA_Error(__FILE__,__LINE__,
"This plugin requires at least %d input channels.",
scale_ch.data + 1);
// bookkeeping
prepared.data = 1;
}

The prepare method checks wether the current setting of the scale_ch variable is possible with
the input signal dimension. It does not adjust the range of the variable, since the range alone
is not sufficient to ensure all future settings are also valid: The scale channel index has to be
even.
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2.3.3.5

CONTENTS

The release method

void example3_t::release(void)
{
prepared.data = 0;
}

The release method is needed for tracking the prepared state only in this example.
2.3.3.6

The signal processing method

mha_wave_t * example3_t::process(mha_wave_t * signal)
{
unsigned int frame;
for(frame = 0; frame < signal->num_frames; frame++)
value(signal,frame,scale_ch.data) *= factor.data;
return signal;
}

The signal processing member function is the same as in example 2.
2.3.3.7

The callback methods

void example3_t::on_scale_ch_writeaccess()
{
printf("Write access: Attempt to set scale_ch=%d.\n", scale_ch.data);
// Can be used to track any writeaccess to the configuration, even
// if it does not change the value. E.g. setting the name of the
// sound file in a string configuration variable can cause a sound
// file player plugin to start playing the sound file from the
// beginning.
}
void example3_t::on_scale_ch_valuechanged()
{
if (scale_ch.data & 1)
throw MHA_Error(__FILE__,__LINE__,
"Attempt to set scale_ch to non-even value %d",
scale_ch.data);
// Can be used to recompute a runtime configuration only if some
// configuration variable actually changed.
}
void example3_t::on_scale_ch_readaccess()
{
printf("scale_ch has been read.\n");
// A configuration variable used as an accumulator can be reset
// after it has been read.
}
void example3_t::on_prereadaccess()
{
printf("A configuration language variable is about to be read.\n");
// Can be used to compute the value on demand.
}
MHAPLUGIN_CALLBACKS(example3,example3_t,wave,wave)

When the writeaccess or valuechanged callbacks throw an MHAError exception, then the
change made to the value of the configuration variable is reverted.
If multiple event sources are connected to a single callback method, then it is not possible
to determine which event has caused the callback to execute. Often, this information is not
crucial, i.e. when the answer to a change of any variable in a set of variables is the same, e.g.
the recomputation of a new runtime configuration that takes all variables of this set as input.
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2.3.4

19

example4.cpp

This plugin is the same as example 3 except that it works on the spectral domain (STFT).
2.3.4.1

The Prepare method

void example4_t::prepare(mhaconfig_t & signal_info)
{
if (signal_info.domain != MHA_SPECTRUM)
throw MHA_Error(__FILE__, __LINE__,
"This plugin can only process spectrum signals.");
// The user may have configured scale_ch before prepare is called.
// Check that the configured channel is present in the input signal.
if (signal_info.channels <= unsigned(scale_ch.data))
throw MHA_Error(__FILE__,__LINE__,
"This plugin requires at least %d input channels.",
scale_ch.data + 1);
// bookkeeping
prepared.data = 1;
}

The prepare method now checks that the signal domain is MHA_SPECTRUM.
2.3.4.2

The signal processing method

mha_spec_t * example4_t::process(mha_spec_t * signal)
{
unsigned int bin;
// spectral signal is stored non-interleaved.
mha_complex_t * channeldata =
signal->buf + signal->num_frames * scale_ch.data;
for(bin = 0; bin < signal->num_frames; bin++)
channeldata[bin] *= factor.data;
return signal;
}

The signal processing member function works on the spectral signal instead of the wave signal
as before.
The mha_spec_t (p. 141) instance stores the complex (mha_complex_t (p. 123)) spectral signal for positive frequences only (since the waveform signal is always real). The num_frames
member of mha_spec_t (p. 141) actually denotes the number of STFT bins.
Please note that different from mha_wave_t (p. 154), a multichannel signal in mha_spec_t
(p. 141) is stored non-interleaved in the signal buffer.
Some arithmetic operations are defined on struct mha_complex_t (p. 123) to facilitate efficient
complex computations. The ∗= operator used here (defined for real and for complex arguments)
is one of them.
2.3.4.3

Connecting the C++ class with the C plugin interface

MHAPLUGIN_CALLBACKS(example4,example4_t,spec,spec)

When connecting a class that performs spectral processing with the C interface, use spec
instead of wave as the domain indicator.
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2.3.5

CONTENTS

example5.cpp

Many algorithms use complex operations to transform the user space variables into run time
configurations. If this takes a noticeable time (e.g. more than 100-500 µ sec), the update of
the runtime configuration can not take place in the real time processing thread. Furthermore,
the parallel access to complex structures may cause unpredictable results if variables are read
while only parts of them are written to memory (cf. section Consistency (p. 15)). To handle
these situations, a special C++ template class MHAPlugin::plugin_t (p. 238) was designed.
This class helps keeping all access to the configuration language variables in the configuration
thread rather than in the processing thread.
The runtime configuration class example5_t is the parameter of the template class MHA←Plugin::plugin_t (p. 238). Its constructor converts the user variables into a runtime configuration. Because the constructor executes in the configuration thread, there is no harm if the
constructor takes a long time. All other member functions and data members of the runtime
configurations are accessed only from the signal processing thread (real-time thread).

class example5_t {
public:
example5_t(unsigned int,unsigned int,mha_real_t);
mha_spec_t* process(mha_spec_t*);
private:
unsigned int channel;
mha_real_t scale;
};

The plugin interface class inherits from the plugin template class MHAPlugin::plugin_←t (p. 238), parameterised by the runtime configuration. Configuration changes (write access
to the variables) will emit a write access event of the changed variables. These events can be
connected to member functions of the interface class by the help of a MHAEvents::patchbay←_t (p. 156) instance.

class plugin_interface_t : public MHAPlugin::plugin_t {
public:
plugin_interface_t(const algo_comm_t&,const std::string&,const std::string&);
mha_spec_t* process(mha_spec_t*);
void prepare(mhaconfig_t&);
private:
void update_cfg();
/* integer variable of MHA-parser: */
MHAParser::int_t scale_ch;
/* float variable of MHA-parser: */
MHAParser::float_t factor;
/* patch bay for connecting configuration parser
events with local member functions: */
MHAEvents::patchbay_t patchbay;
};

The constructor of the runtime configuration analyses and validates the user variables. If the
configuration is invalid, an exception of type MHA_Error (p. 132) is thrown. This will cause
the openMHA configuration language command which caused the change to fail: The modified
configuration language variable is then reset to its original value, and the error message will
contain the message string of the MHA_Error (p. 132) exception.
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example5_t::example5_t(unsigned int ichannel,
unsigned int numchannels,
mha_real_t iscale)
: channel(ichannel),scale(iscale)
{
if( channel >= numchannels )
throw MHA_Error(__FILE__,__LINE__,
"Invalid channel number %d (only %d channels configured).",
channel,numchannels);
}

In this example, the run time configuration class example5_t has a signal processing member
function. In this function, the selected channel is scaled by the given scaling factor.
mha_spec_t* example5_t::process(mha_spec_t* spec)
{
/* Scale channel number "scale_ch" by "factor": */
for(unsigned int fr = 0; fr < spec->num_frames; fr++){
spec->buf[fr + channel * spec->num_frames].re *= scale;
spec->buf[fr + channel * spec->num_frames].im *= scale;
}
return spec;
}

The constructor of the example plugin class is similar to the previous examples. A callback
triggered on write access to the variables is registered using the MHAEvents::patchbay_t
(p. 156) instance.
plugin_interface_t::plugin_interface_t(
const algo_comm_t& iac,
const std::string&,const std::string&)
: MHAPlugin::plugin_t("example plugin configuration structure",iac),
/* initialzing variable 'scale_ch' with MHAParser::int_t(char* name, .... ) */
scale_ch("channel number to be scaled","0","[0,["),
/* initialzing variable 'factor' with MHAParser::float_t(char* name, .... ) */
factor("scale factor","1.0","[0,2]")
{
/* Register variables to the configuration parser: */
insert_item("channel",&scale_ch);
insert_item("factor",&factor);
/*
* On write access to the parser variables a notify callback of
* this class will be called. That funtion will update the runtime
* configuration.
*/
patchbay.connect(&scale_ch.writeaccess,this,&plugin_interface_t::update_cfg);
patchbay.connect(&factor.writeaccess,this,&plugin_interface_t::update_cfg);
}

The processing function can gather the latest valid runtime configuration by a call of poll_←config. On success, the class member cfg points to this configuration. On error, if there is
no usable runtime configuration instance, an exception is thrown. In this example, the prepare
method ensures that there is a valid runtime configuration, so that in this example, no error can
be raised at this point. The prepare method is always executed before the process method is
called. The runtime configuration class in this example provides a signal processing method.
The process method of the plugin interface calls the process method of this instance to perform
the actual signal processing.
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mha_spec_t* plugin_interface_t::process(mha_spec_t* spec)
{
poll_config();
return cfg->process(spec);
}

The prepare method ensures that a valid runtime configuration exists by creating a new runtime
configuration from the current configuration language variables. If the configuraion is invalid,
then an exception of type MHA_Error (p. 132) is raised and the preparation of the openMHA
fails with an error message.

void plugin_interface_t::prepare(mhaconfig_t& tfcfg)
{
if( tfcfg.domain != MHA_SPECTRUM )
throw MHA_Error(__FILE__,__LINE__,
"Example5: Only spectral processing is supported.");
/* remember the transform configuration (i.e. channel numbers): */
tftype = tfcfg;
/* make sure that a valid runtime configuration exists: */
update_cfg();
}

The update_cfg member function is called when the value of a configuration language variable
changes, or from the prepare method. It allocates a new runtime configuration and registers it
for later access from the real time processing thread. The function push_config (p. 238) stores
the configuration in a FiFo queue of runtime configurations. Once they are inserted in the FiFo,
the MHAPlugin::plugin_t (p. 238) template is responsible for deleting runtime configuration
instances stored in the FiFo. You don't need to keep track of the created instances, and you
must not delete them yourself.

void plugin_interface_t::update_cfg()
{
if( tftype.channels )
push_config(new example5_t(scale_ch.data,tftype.channels,factor.data));
}

In the end of the example code file, the macro MHAPLUGIN_CALLBACKS (p. 8) defines all
ANSI-C interface functions and passes them to the corresponding C++ class member functions (partly defined by the MHAPlugin::plugin_t (p. 238) template class). All exceptions of
type MHA_Error (p. 132) are caught and transformed into an appropriate error code and error
message.

MHAPLUGIN_CALLBACKS(example5,plugin_interface_t,spec,spec)

© 2005-2018 HörTech gGmbH, Oldenburg

2.3

2.3.6

Writing openMHA Plugins. A step-by-step tutorial

23

example6.cpp

This last example is the same as the previous one, but it additionally creates an 'Algorithm
Communication Variable' (AC variable). It calculates the RMS level of a given channel and
stores it into this variable. The variable can be accessed by any other algorithm in the same
chain. To store the data onto disk, the 'acsave' plugin can be used. 'acmon' is a plugin which
converts AC variables into parsable monitor variables.
In the constructor of the plugin class the variable rmsdb is registered under the name
example6_rmslev as a one-dimensional AC variable of type float. For registration of other
types, read access and other detailed informations please see Communication between algorithms (p. 27).

example6_t::example6_t(const algo_comm_t& iac,
const std::string&,const std::string&)
: MHAPlugin::plugin_t("example plugin configuration structure",iac),
/* initialzing variable 'channel_no' with MHAParser::int_t(char* name, .... ) */
channel_no("channel in which the RMS level is measured","0","[0,[")
{
/* Register variables to the configuration parser: */
insert_item("channel",&channel_no);
/*
* On write access to the parser variables a notify callback of
* this class will be called. That funtion will update the runtime
* configuration.
*/
patchbay.connect(&channel_no.writeaccess,this,&example6_t::update_cfg);
/*
* Propagate the level variable to all algorithms in the
* processing chain. If multiple instances of this algorithm are
* required, than it is necessary to use different names for this
* variable (i.e. prefixing the name with the algorithm name
* passed to MHAInit).
*/
ac.insert_var_float( ac.handle, "example6_rmslev", &rmsdb );
}

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24

2.3.7

CONTENTS

Debugging openMHA plugins

Suppose you would want to step through the code of your openMHA plugin with a debugger. This example details how to use the linux gdb debugger to inspect the example6_←t::prepare() and example6_t::process() routines of example6.cpp (p. 23) example
6.
First, make sure that your plugin is compiled with the compiler option to include debugging
symbols: Apply the -ggdb switch to all gcc, g++ invocations.
Once the plugin is compiled, with debugging symbols, create a test configuration. For example
6, assuming there is an audio file named input.wav in your working directory, you could create
a configuration file named ‘debugexample6.cfg', with the following content:
# debugexample6.cfg
fragsize = 64
srate = 44100
nchannels_in = 2
iolib = MHAIOFile
io.in = input.wav
io.out = output.wav
mhalib = example6
mha.channel = 1
cmd=start

Assuming all your binaries and shared-object libraries are in your ‘bin' directory (see READ←ME.md), you could start gdb using
$ export MHA_LIBRARY_PATH=$PWD/bin
$ gdb $MHA_LIBRARY_PATH/mha

Set breakpoints in prepare and process methods, and start execution. Note that specifying
the breakpoint by symbol (example6_t::prepare) does not yet work, as the symbol lives in
the openMHA plugin that has not yet been loaded. Specifying by line number works, however.
Specifying the breakpoint by symbol also works once the plugin is loaded (i.e. when the debugger stops in the first break point). You can set the breakpoints like this (example shown here is
run in gdb version 7.11.1):
(gdb) run ?read:debugexample6.cfg
Starting program: {openMHA_directory}/bin/mha ?read:debugexample6.cfg
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
The Open Master Hearing Aid (openMHA) server
Copyright (c) 2005-2017 HoerTech gGmbH, D-26129 Oldenburg, Germany
This program comes with ABSOLUTELY NO WARRANTY; for details see file COPYING.
This is free software, and you are welcome to redistribute it
under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE, Version 3;
for details see file COPYING.

Breakpoint 1, example6_t::prepare (this=0x6478b0, tfcfg=...)
at example6.cpp:192
192
if( tfcfg.domain != MHA_WAVEFORM )
(gdb) b example6.cpp:162
Breakpoint 2 at 0x7ffff589744a: file example6.cpp, line 162.
(gdb) c
Continuing.

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2.3

Writing openMHA Plugins. A step-by-step tutorial

25

Where ‘{openMHA_directory}' is the directory where openMHA is located (which should also
be your working directory in this case). Next stop is the process() method. You can now
examine and change the variables, step through the program as needed (using, for example ‘n'
to step in the next line):

Breakpoint 2, example6_t::process (this=0x7ffff6a06c0d, wave=0x10a8b550)
at example6.cpp:162
162
{
(gdb) n
163
poll_config();
(gdb)

© 2005-2018 HörTech gGmbH, Oldenburg

26

2.4

CONTENTS

The MHA Framework interface

© 2005-2018 HörTech gGmbH, Oldenburg

2.5

Communication between algorithms

2.5

Communication between algorithms

27

Algorithms within one chain can share variables for communication with other algorithms.
Collaboration diagram for Communication between algorithms:

Communication between
algorithms

mha_algo_comm.h

The openMHA Toolbox
library

Files
• file mha_algo_comm.h
Header file for Algorithm Communication.

Namespaces
• MHA_AC
Functions and classes for Algorithm Communication (AC) support.

Classes
• class MHA_AC::spectrum_t
Insert a MHASignal::spectrum_t ( p. 261) class into the AC space.

• class MHA_AC::waveform_t
Insert a MHASignal::waveform_t ( p. 268) class into the AC space.

• class MHA_AC::int_t
Insert a integer variable into the AC space.

• class MHA_AC::float_t
Insert a float point variable into the AC space.

• class MHA_AC::double_t
Insert a double precision floating point variable into the AC space.

• class MHA_AC::ac2matrix_t
Copy AC variable to a matrix.

• class MHA_AC::acspace2matrix_t
Copy all or a subset of all numeric AC variables into an array of matrixes.

• struct algo_comm_t
A reference handle for algorithm communication variables.

• struct comm_var_t
Algorithm communication variable structure.
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CONTENTS

Functions
• mha_spec_t MHA_AC::get_var_spectrum (algo_comm_t ac, const std::string &name)
Convert an AC variable into a spectrum.

• mha_wave_t MHA_AC::get_var_waveform (algo_comm_t ac,
&name)

const std::string

Convert an AC variable into a waveform.

• int MHA_AC::get_var_int (algo_comm_t ac, const std::string &name)
Return value of an integer scalar AC variable.

• float MHA_AC::get_var_float (algo_comm_t ac, const std::string &name)
Return value of an floating point scalar AC variable.

• std::vector< float > MHA_AC::get_var_vfloat (algo_comm_t ac, const std::string
&name)
Return value of an floating point vector AC variable as standard vector of floats.

2.5.1

Detailed Description

This mechanism allows interaction between algorithms (i.e. separation of noise estimation
and noise reduction algorithms, combination of dynamic compression and noise estimation).
Through a set of simple C functions, algorithms can propagate variables of any type, even C++
classes, to other algorithms.
An algorithm communication handle (algo_comm_t (p. 88)) is passed at initialisation time to the
constructor of each plugin class constructor (p. 238). This handle contains a reference handle,
algo_comm_t::handle (p. 88), and a number of function pointers, algo_comm_t::insert_var
(p. 88) etc.. An algorithm communication variable is an object of type comm_var_t (p. 95).
For AC variables of numeric types, openMHA Plugins for conversion into parsable monitor
variables, acmon, and storage into Matlab or text files, acsave, are available.

2.5.2

Function Documentation

2.5.2.1 mha_spec_t MHA_AC::get_var_spectrum ( algo_comm_t ac, const std::string & name )
This function reads an AC variable and tries to convert it into a valid spectrum. The Spectrum
variable is granted to be valid only for one call of the processing function.
Parameters
ac
name

AC handle
Name of the variable

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2.5

Communication between algorithms

29

Returns
Spectrum structure

2.5.2.2 mha_wave_t MHA_AC::get_var_waveform ( algo_comm_t ac, const std::string & name )
This function reads an AC variable and tries to convert it into a valid waveform. The waveform
variable is granted to be valid only for one call of the processing function.
Parameters
ac
name

AC handle
Name of the variable

Returns
waveform structure

2.5.2.3

int MHA_AC::get_var_int ( algo_comm_t ac, const std::string & name )

Parameters
ac
name

AC handle
Name of the variable

Returns
Variable value

2.5.2.4

float MHA_AC::get_var_float ( algo_comm_t ac, const std::string & name )

Parameters
ac
name

AC handle
Name of the variable

Returns
Variable value

2.5.2.5

std::vector< float > MHA_AC::get_var_vfloat ( algo_comm_t ac, const std::string & name )

© 2005-2018 HörTech gGmbH, Oldenburg

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CONTENTS

Parameters
ac
name

AC handle
Name of the variable

Returns
Variable value

© 2005-2018 HörTech gGmbH, Oldenburg

2.6

Error handling in the openMHA

2.6

Error handling in the openMHA

31

Errors are reported to the user via the MHA_Error (p. 132) exception.
Collaboration diagram for Error handling in the openMHA:

The openMHA Toolbox
library

Error handling in the
openMHA

Classes
• class MHA_Error
Error reporting exception class.

Macros
• #define MHA_ErrorMsg(x) MHA_Error(__FILE__,__LINE__,"%s",x)
Throw an openMHA error with a text message.

• #define MHA_assert(x)
false.",#x)

if(!(x))

throw

MHA_Error(__FILE__,__LINE__,"\"%s\"

is

Assertion macro, which throws an MHA_Error ( p. 132).

• #define MHA_assert_equal(a, b) if( a != b ) throw MHA_Error(__FILE__,__LINE__←,"\"%s == %s\" is false (%s = %g, %s = %g).",#a,#b,#a,(double)(a),#b,(double)(b))
Equality assertion macro, which throws an MHA_Error ( p. 132) with the values.

Functions
• void mha_debug (const char ∗fmt,...)
Print an info message (stderr on Linux, OutputDebugString in Windows).

2.6.1

Detailed Description

2.6.2

Macro Definition Documentation

2.6.2.1

#define MHA_ErrorMsg( x ) MHA_Error(__FILE__,__LINE__,"%s",x)

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CONTENTS

Parameters
x

Text message.

2.6.2.2

#define MHA_assert( x ) if(!(x)) throw MHA_Error(__FILE__,__LINE__,"\"%s\" is false.",#x)

Parameters
x

Boolean expression which should be true.

2.6.2.3

#define MHA_assert_equal( a, b ) if( a != b ) throw MHA_Error(__FILE__,__LINE__,"\"%s ==
%s\" is false (%s = %g, %s = %g).",#a,#b,#a,(double)(a),#b,(double)(b))

Parameters
a
b

Numeric expression which can be converted to double (for printing).
Numeric expression which should be equal to a

© 2005-2018 HörTech gGmbH, Oldenburg

2.7

The openMHA configuration language

2.7

The openMHA configuration language

33

openMHA Plugins that should use the openMHA configuration language for their configuration
have to be implemented in C++ and need to include mha_parser.hh (p. 293).
All required classes and functions for parser access are declared in the namespace MH←AParser (p. 76). The plugin class should be derived from the class MHAParser::parser_t
(p. 220) (or MHAPlugin::plugin_t (p. 238)), which symbolises a sub-parser node in the open←MHA script hierarchy. Variables of many types can be registered to the sub-parser node by
calling the member function insert_item (p. 222).
The openMHA Plugin template class MHAPlugin::plugin_t (p. 238) together with the Plugin
macro MHAPLUGIN_CALLBACKS (p. 8) provide the callback mappings and correct inheritance. If your plugin is based on that template class, you simply have to use the insert_item
command to give access to your variables, everything else is managed internally.
A complete list of all openMHA script items is given in the description of the MHAParser (p. 76)
namespace.

© 2005-2018 HörTech gGmbH, Oldenburg

34

2.8

CONTENTS

The openMHA Toolbox library

The openMHA toolbox is a static C++ library which makes it more comfortable to develop
openMHA plugins.
Collaboration diagram for The openMHA Toolbox library:

Vector and matrix processing
toolbox
MHASignal
Complex arithmetics
in the openMHA
The openMHA Toolbox
library

Error handling in the
openMHA
mha_algo_comm.h

Fast Fourier Transform
functions

Communication between
algorithms

Modules
• Error handling in the openMHA
Errors are reported to the user via the MHA_Error ( p. 132) exception.

• Vector and matrix processing toolbox
The vector and matrix processing toolbox consists of a number of classes defined in the
namespace MHASignal ( p. 81), and many functions and operators for use with the structures
mha_wave_t ( p. 154) and mha_spec_t ( p. 141).

• Complex arithmetics in the openMHA
• Fast Fourier Transform functions

Files
• file mha_algo_comm.h
Header file for Algorithm Communication.

• file mha_filter.hh
Header file for IIR filter classes.

• file mha_signal.hh
Header file for audio signal handling and processing classes.

• file mha_tablelookup.hh
Header file for table lookup classes.
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2.8

The openMHA Toolbox library

35

Namespaces
• MHAOvlFilter
Namespace for overlapping FFT based filter bank classes and functions.

• MHAFilter
Namespace for IIR and FIR filter classes.

• MHAParser
Name space for the openMHA-Parser configuration language.

• MHASignal
Namespace for audio signal handling and processing classes.

• MHATableLookup
Namespace for table lookup classes.

2.8.1

Detailed Description

It contains the openMHA script language classes.

© 2005-2018 HörTech gGmbH, Oldenburg

36

2.9

CONTENTS

Vector and matrix processing toolbox

The vector and matrix processing toolbox consists of a number of classes defined in the namespace MHASignal (p. 81), and many functions and operators for use with the structures mha←_wave_t (p. 154) and mha_spec_t (p. 141).
Collaboration diagram for Vector and matrix processing toolbox:

Vector and matrix processing
toolbox

MHASignal

The openMHA Toolbox
library

Namespaces
• MHASignal
Namespace for audio signal handling and processing classes.

• MHAWindow
Collection of Window types.

Classes
• struct mha_wave_t
Waveform signal structure.

• struct mha_spec_t
Spectrum signal structure.

• struct mha_audio_descriptor_t
Description of an audio fragment (planned as a replacement of mhaconfig_t ( p. 155)).

• struct mha_audio_t
An audio fragment in the openMHA (planned as a replacement of mha_wave_t ( p. 154) and
mha_spec_t ( p. 141)).

• class MHASignal::spectrum_t
a signal processing class for spectral data (based on mha_spec_t ( p. 141))

• class MHASignal::waveform_t
signal processing class for waveform data (based on mha_wave_t ( p. 154))

• class MHASignal::doublebuffer_t
Double-buffering class.

• class MHASignal::hilbert_t
Hilbert transformation of a waveform segment.

• class MHASignal::minphase_t
Minimal phase function.

• class MHASignal::uint_vector_t
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2.9

Vector and matrix processing toolbox

37

Vector of unsigned values, used for size and index description of n-dimensional matrixes.

• class MHASignal::matrix_t
n-dimensional matrix with real or complex floating point values.

• class MHAParser::window_t
MHA configuration interface for a window function generator.

• class MHASignal::delay_wave_t
Delayline containing wave fragments.

• class MHASignal::async_rmslevel_t
Class for asynchronous level metering.

Typedefs
• typedef float mha_real_t
openMHA type for real numbers

Functions
• mha_wave_t range (mha_wave_t s, unsigned int k0, unsigned int len)
Return a time interval from a waveform chunk.

• mha_spec_t channels (mha_spec_t s, unsigned int ch_start, unsigned int nch)
Return a channel interval from a spectrum.

• void MHASignal::for_each (mha_wave_t ∗s, mha_real_t(∗fun)(mha_real_t))
Apply a function to each element of a mha_wave_t ( p. 154).

• mha_real_t MHASignal::lin2db (mha_real_t x)
Conversion from linear scale to dB (no SPL reference)

• mha_real_t MHASignal::db2lin (mha_real_t x)
Conversion from dB scale to linear (no SPL reference)

• mha_real_t MHASignal::pa2dbspl (mha_real_t x)
Conversion from linear Pascal scale to dB SPL.

• mha_real_t MHASignal::pa22dbspl (mha_real_t x, mha_real_t eps=1e-20f)
Conversion from squared Pascal scale to dB SPL.

• mha_real_t MHASignal::dbspl2pa (mha_real_t x)
Conversion from dB SPL to linear Pascal scale.

• mha_real_t MHASignal::smp2sec (mha_real_t n, mha_real_t srate)
conversion from samples to seconds

• mha_real_t MHASignal::sec2smp (mha_real_t sec, mha_real_t srate)
conversion from seconds to samples

• mha_real_t MHASignal::bin2freq (mha_real_t bin, unsigned fftlen, mha_real_t srate)
conversion from fft bin index to frequency

• mha_real_t MHASignal::freq2bin (mha_real_t freq, unsigned fftlen, mha_real_t srate)
conversion from frequency to fft bin index

• mha_real_t MHASignal::smp2rad (mha_real_t samples, unsigned bin, unsigned fftlen)
conversion from delay in samples to phase shift
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CONTENTS

• mha_real_t MHASignal::rad2smp (mha_real_t phase_shift, unsigned bin, unsigned
fftlen)
conversion from phase shift to delay in samples

• template
std::vector< elem_type > MHASignal::dupvec (std::vector< elem_type > vec, unsigned
n)
Duplicate last vector element to match desired size.

• template
std::vector< elem_type > MHASignal::dupvec_chk (std::vector< elem_type > vec, unsigned n)
Duplicate last vector element to match desired size, check for dimension.

• bool equal_dim (const mha_wave_t &a, const mha_wave_t &b)
Test for equal dimension of waveform structures.

• bool equal_dim (const mha_wave_t &a, const mhaconfig_t &b)
Test for match of waveform dimension with mhaconfig structure.

• bool equal_dim (const mha_spec_t &a, const mha_spec_t &b)
Test for equal dimension of spectrum structures.

• bool equal_dim (const mha_spec_t &a, const mhaconfig_t &b)
Test for match of spectrum dimension with mhaconfig structure.

• bool equal_dim (const mha_wave_t &a, const mha_spec_t &b)
Test for equal dimension of waveform/spectrum structures.

• bool equal_dim (const mha_spec_t &a, const mha_wave_t &b)
Test for equal dimension of waveform/spectrum structures.

• void integrate (mha_wave_t &s)
Numeric integration of a signal vector (real values)

• void integrate (mha_spec_t &s)
Numeric integration of a signal vector (complex values)

• unsigned int size (const mha_wave_t &s)
Return size of a waveform structure.

• unsigned int size (const mha_spec_t &s)
Return size of a spectrum structure.

• unsigned int size (const mha_wave_t ∗s)
Return size of a waveform structure.

• unsigned int size (const mha_spec_t ∗s)
Return size of a spectrum structure.

• void clear (mha_wave_t &s)
Set all values of waveform to zero.

• void clear (mha_wave_t ∗s)
Set all values of waveform to zero.

• void clear (mha_spec_t &s)
Set all values of spectrum to zero.

• void clear (mha_spec_t ∗s)
Set all values of spectrum to zero.

• void assign (mha_wave_t self, mha_real_t val)
Set all values of waveform 'self' to 'val'.
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2.9

Vector and matrix processing toolbox

39

• void assign (mha_wave_t self, const mha_wave_t &val)
Set all values of waveform 'self' to 'val'.

• void assign (mha_spec_t self, const mha_spec_t &val)
Set all values of spectrum 'self' to 'val'.

• void timeshift (mha_wave_t &self, int shift)
Time shift of waveform chunk.

• mha_real_t & value (mha_wave_t ∗s, unsigned int fr, unsigned int ch)
Access an element of a waveform structure.

• const mha_real_t & value (const mha_wave_t ∗s, unsigned int fr, unsigned int ch)
Constant access to an element of a waveform structure.

• mha_complex_t & value (mha_spec_t ∗s, unsigned int fr, unsigned int ch)
Access to an element of a spectrum.

• const mha_complex_t & value (const mha_spec_t ∗s, unsigned int fr, unsigned int ch)
Constant access to an element of a spectrum.

• mha_real_t & value (mha_wave_t &s, unsigned int fr, unsigned int ch)
Access to an element of a waveform structure.

• const mha_real_t & value (const mha_wave_t &s, unsigned int fr, unsigned int ch)
Constant access to an element of a waveform structure.

• mha_complex_t & value (mha_spec_t &s, unsigned int fr, unsigned int ch)
Access to an element of a spectrum.

• const mha_complex_t & value (const mha_spec_t &s, unsigned int fr, unsigned int ch)
Constant access to an element of a spectrum.

• std::vector< float > std_vector_float (const mha_wave_t &)
Converts a mha_wave_t ( p. 154) structure into a std::vector (interleaved order).

• std::vector< std::vector< float > > std_vector_vector_float (const mha_wave_t &)
Converts a mha_wave_t ( p. 154) structure into a std::vector< std::vector > (outer vector represents channels).

• std::vector< std::vector< mha_complex_t > > std_vector_vector_complex (const
mha_spec_t &)
Converts a mha_spec_t ( p. 141) structure into a std::vector< std::vector >
(outer vector represents channels).

• mha_wave_t & operator+= (mha_wave_t &, const mha_real_t &)
Addition operator.

• mha_wave_t & operator+= (mha_wave_t &, const mha_wave_t &)
Addition operator.

• mha_wave_t & operator-= (mha_wave_t &, const mha_wave_t &)
Subtraction operator.

• mha_spec_t & operator-= (mha_spec_t &, const mha_spec_t &)
Subtraction operator.

• mha_wave_t & operator∗= (mha_wave_t &, const mha_real_t &)
Element-wise multiplication operator.

• mha_wave_t & operator∗= (mha_wave_t &, const mha_wave_t &)
Element-wise multiplication operator.

• mha_spec_t & operator∗= (mha_spec_t &, const mha_real_t &)
Element-wise multiplication operator.
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CONTENTS

• mha_spec_t & operator∗= (mha_spec_t &, const mha_wave_t &)
Element-wise multiplication operator.

• mha_spec_t & operator∗= (mha_spec_t &, const mha_spec_t &)
Element-wise multiplication operator.

• mha_spec_t & operator/= (mha_spec_t &, const mha_spec_t &)
Element-wise division operator.

• mha_wave_t & operator/= (mha_wave_t &, const mha_wave_t &)
Element-wise division operator.

• mha_spec_t & operator+= (mha_spec_t &, const mha_spec_t &)
Addition operator.

• mha_spec_t & operator+= (mha_spec_t &, const mha_real_t &)
Addition operator.

• mha_wave_t & operator∧ = (mha_wave_t &self, const mha_real_t &arg)
Exponent operator.

• void MHASignal::copy_channel (mha_spec_t &self, const mha_spec_t &src, unsigned
sch, unsigned dch)
Copy one channel of a source signal.

• void MHASignal::copy_channel (mha_wave_t &self, const mha_wave_t &src, unsigned src_channel, unsigned dest_channel)
Copy one channel of a source signal.

• mha_real_t MHASignal::rmslevel (const mha_spec_t &s, unsigned int channel, unsigned int fftlen)
Return RMS level of a spectrum channel.

• mha_real_t MHASignal::colored_intensity (const mha_spec_t &s, unsigned int channel, unsigned int fftlen, mha_real_t sqfreq_response[ ])
Colored spectrum intensity.

• mha_real_t MHASignal::maxabs (const mha_spec_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t MHASignal::rmslevel (const mha_wave_t &s, unsigned int channel)
Return RMS level of a waveform channel.

• mha_real_t MHASignal::maxabs (const mha_wave_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t MHASignal::maxabs (const mha_wave_t &s)
Find maximal absolute value.

• mha_real_t MHASignal::max (const mha_wave_t &s)
Find maximal value.

• mha_real_t MHASignal::min (const mha_wave_t &s)
Find minimal value.

• mha_real_t MHASignal::sumsqr_channel (const mha_wave_t &s, unsigned int channel)
Calculate sum of squared values in one channel.

• mha_real_t MHASignal::sumsqr_frame (const mha_wave_t &s, unsigned int frame)
Calculate sum over all channels of squared values.

• void conjugate (mha_spec_t &self)
Replace (!) the value of this mha_spec_t ( p. 141) with its conjugate.
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Vector and matrix processing toolbox

2.9.1

Detailed Description

2.9.2

Typedef Documentation

2.9.2.1

41

typedef float mha_real_t

This type is expected to be allways the C-type 'float' (IEEE 754 single).

2.9.3

Function Documentation

2.9.3.1 mha_wave_t range ( mha_wave_t s, unsigned int k0, unsigned int len )
A waveform chunk containing a time intervall of a larger waveform chunk is returned. The
number of channels remains constant. The data of the output waveform structure points to
the data of the input structure, i.e., write access to the output waveform chunk modifies the
corresponding entries in the input chunk.
Parameters
s
k0

Waveform structure
Index of first value in output

len

Number of frames in output

Returns
Waveform structure representing the sub-interval.

2.9.3.2 mha_spec_t channels ( mha_spec_t s, unsigned int ch_start, unsigned int nch )
Parameters
s

Input spectrum

ch_start

Index of first channel in output

nch

Number of channels in output

Returns
Spectrum structure representing the sub-interval.

2.9.3.3

void MHASignal::for_each ( mha_wave_t ∗ s, mha_real_t(∗)(mha_real_t) fun )
[inline]

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CONTENTS

Parameters
s

Pointer to a mha_wave_t (p. 154) structure

fun

Function to be applied (one argument)

2.9.3.4 mha_real_t MHASignal::lin2db ( mha_real_t x ) [inline]
Parameters
x

Linear input.

2.9.3.5 mha_real_t MHASignal::db2lin ( mha_real_t x ) [inline]
Parameters
x

dB input.

2.9.3.6 mha_real_t MHASignal::pa2dbspl ( mha_real_t x ) [inline]
Parameters
x

Linear input.

2.9.3.7 mha_real_t MHASignal::pa22dbspl ( mha_real_t x, mha_real_t eps = 1e-20f )
[inline]
Parameters
squared pascal input
minimum squared-pascal value

x
eps

2.9.3.8 mha_real_t MHASignal::dbspl2pa ( mha_real_t x ) [inline]
Parameters
x

Linear input.

2.9.3.9 mha_real_t MHASignal::smp2sec ( mha_real_t n, mha_real_t srate ) [inline]
Parameters
n

number of samples

srate

sampling rate / Hz
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2.9.3.10 mha_real_t MHASignal::sec2smp ( mha_real_t sec, mha_real_t srate ) [inline]
Parameters
sec
srate

time in seconds
sampling rate / Hz

Returns
number of samples, generally has non-zero fractional part

2.9.3.11 mha_real_t MHASignal::bin2freq ( mha_real_t bin, unsigned fftlen, mha_real_t srate )
[inline]
Parameters
bin
fftlen

index of fft bin, index 0 has dc
FFT length

srate

sampling frequency / Hz

Returns
frequency of fft bin / Hz

2.9.3.12 mha_real_t MHASignal::freq2bin ( mha_real_t freq, unsigned fftlen, mha_real_t srate )
[inline]
Parameters
freq

frequency / Hz

fftlen

FFT length

srate

sampling frequency / Hz

Returns
0-based index of fft bin, generally has non-zero fractional part

2.9.3.13 mha_real_t MHASignal::smp2rad ( mha_real_t samples, unsigned bin, unsigned fftlen )
[inline]
Compute phase shift that needs to be applied to fft spectrum to achieve the desired delay.
Parameters
samples

delay in samples. Positive delay: shift current signal to future.

bin

index of fft bin, index 0 has dc (index 0 and nyqvist bin cannot be delayed)

© fftlen
2005-2018 HörTech
gGmbH, Oldenburg
FFT length

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CONTENTS

Returns
The phase shift in radiant that needs to be applied to fft bin to achieve the desired delay. A
positive delay requires a negative phase shift. If required phase shift is >pi or <-pi, then
the desired delay cannot be applied in the fft domain with given parameters. Required
phase shifts close to pi should not be used. If bin is 0 or nyqvist, returns 0 phase shift.

2.9.3.14 mha_real_t MHASignal::rad2smp ( mha_real_t phase_shift, unsigned bin, unsigned fftlen
) [inline]
Compute delay in samples that is achieved by a phase shift.
Parameters
phase_shift

phase shift in radiant

bin

index of fft bin, index 0 has dc (index 0 and nyqvist bin cannot be delayed)

fftlen

FFT length

Returns
The delay in samples achieved by applying the phase shift. A negative phase shift causes
a positive delay: shifts current signal to future.

2.9.3.15

template std::vector MHASignal::dupvec ( std::vector<
elem_type > vec, unsigned n )

Parameters
vec

Input vector.

n

Target number of elements.

Return values
Resized

2.9.3.16

vector.

template std::vector MHASignal::dupvec_chk ( std::vector<
elem_type > vec, unsigned n )

The input dimension can be either 1 or the target length.
Parameters
vec

Input vector.

n

Target number of elements.

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Return values
Resized

2.9.3.17

vector.

bool equal_dim ( const mha_wave_t & a, const mha_spec_t & b ) [inline]

Warning
Waveform structures mha_wave_t (p. 154) use interleaved data order, while spectrum
structures mha_spec_t (p. 141) use non-interleaved.

2.9.3.18

bool equal_dim ( const mha_spec_t & a, const mha_wave_t & b ) [inline]

Warning
Waveform structures mha_wave_t (p. 154) use interleaved data order, while spectrum
structures mha_spec_t (p. 141) use non-interleaved.

2.9.3.19

void integrate ( mha_wave_t & s )

Parameters
s

Input signal vector

2.9.3.20

void integrate ( mha_spec_t & s )

Parameters
s

Input signal vector

2.9.3.21

void assign ( mha_wave_t self, mha_real_t val ) [inline]

Parameters
self
val

2.9.3.22

Waveform to be modified.
Value to be assigned to all entries of waveform.

void assign ( mha_wave_t self, const mha_wave_t & val )

Parameters
self
val

Waveform to be modified.
Source waveform structure.

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2.9.3.23

CONTENTS

void assign ( mha_spec_t self, const mha_spec_t & val )

Parameters
self

Spectrum to be modified.

val

Source spectrum.

2.9.3.24

void timeshift ( mha_wave_t & self, int shift )

Shifted areas are filled with zeros.
Parameters
Waveform chunk to be shifted
Shift amount, positive values shift to later times

self
shift

2.9.3.25 mha_real_t& value ( mha_wave_t ∗ s, unsigned int fr, unsigned int ch ) [inline]
Parameters
s
fr
ch

Waveform structure
Frame number
Channel number

Returns
Reference to element

2.9.3.26

const mha_real_t& value ( const mha_wave_t ∗ s, unsigned int fr, unsigned int ch )
[inline]

Parameters
s
fr
ch

Waveform structure
Frame number
Channel number

Returns
Reference to element

2.9.3.27 mha_complex_t& value ( mha_spec_t ∗ s, unsigned int fr, unsigned int ch ) [inline]

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Parameters
s

Spectrum structure

fr
ch

Bin number
Channel number

Returns
Reference to element

2.9.3.28

const mha_complex_t& value ( const mha_spec_t ∗ s, unsigned int fr, unsigned int ch )
[inline]

Parameters
s

Spectrum structure

fr
ch

Bin number
Channel number

Returns
Reference to element

2.9.3.29 mha_real_t& value ( mha_wave_t & s, unsigned int fr, unsigned int ch ) [inline]
Parameters
s
fr
ch

Waveform structure
Frame number
Channel number

Returns
Reference to element

2.9.3.30

const mha_real_t& value ( const mha_wave_t & s, unsigned int fr, unsigned int ch )
[inline]

Parameters
s
fr
ch

Waveform structure
Frame number
Channel number

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CONTENTS

Returns
Reference to element

2.9.3.31 mha_complex_t& value ( mha_spec_t & s, unsigned int fr, unsigned int ch )
[inline]
Parameters
s

Spectrum structure

fr
ch

Bin number
Channel number

Returns
Reference to element

2.9.3.32

const mha_complex_t& value ( const mha_spec_t & s, unsigned int fr, unsigned int ch )
[inline]

Parameters
s

Spectrum structure

fr
ch

Bin number
Channel number

Returns
Reference to element
2.9.3.33

std::vector std_vector_float ( const mha_wave_t & )

Warning
This function is not real-time safe. Do not use in signal processing thread.
2.9.3.34

std::vector > std_vector_vector_float ( const mha_wave_t & )

Warning
This function is not real-time safe. Do not use in signal processing thread.
2.9.3.35

std::vector > std_vector_vector_complex ( const
mha_spec_t & )

Warning
This function is not real-time safe. Do not use in signal processing thread.

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2.9.3.36 mha_wave_t& operator∧ = ( mha_wave_t & self, const mha_real_t & arg )
Warning
This overwrites the xor operator!

2.9.3.37

void MHASignal::copy_channel ( mha_spec_t & self, const mha_spec_t & src, unsigned
sch, unsigned dch )

Parameters
Destination.
Source
Source channel number
Destination channel number

self
src
sch
dch

2.9.3.38

void MHASignal::copy_channel ( mha_wave_t & self, const mha_wave_t & src, unsigned
src_channel, unsigned dest_channel )

Parameters
self
src
src_channel
dest_channel

Destination.
Source
Source channel number
Destination channel number

2.9.3.39 mha_real_t MHASignal::rmslevel ( const mha_spec_t & s, unsigned int channel, unsigned
int fftlen )
Parameters
s

Input spectrum

channel
fftlen

Channel number to be tested
FFT length (to correctly count the level of the Nyquist bin)

Returns
RMS level in Pa

2.9.3.40 mha_real_t MHASignal::colored_intensity ( const mha_spec_t & s, unsigned int channel,
unsigned int fftlen, mha_real_t sqfreq_response[ ] )
computes the squared sum of the spectrum after filtering with the frequency response

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CONTENTS

Parameters
s

Input spectrum

channel
fftlen

Channel number to be tested
FFT length (to correctly count the level of the Nyquist bin)

sqfreq_response

A squared weighting factor for every fft bin.

Returns
sum of squares. Root of this is the colored level in Pa

2.9.3.41 mha_real_t MHASignal::maxabs ( const mha_spec_t & s, unsigned int channel )
Parameters
s

Input signal

channel

Channel to be tested

Returns
maximum absolute value

2.9.3.42 mha_real_t MHASignal::rmslevel ( const mha_wave_t & s, unsigned int channel )
Parameters
s

Input waveform signal

channel

Channel number to be tested

Returns
RMS level in Pa

2.9.3.43 mha_real_t MHASignal::maxabs ( const mha_wave_t & s, unsigned int channel )
Parameters
s

Input signal

channel

Channel to be tested

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Returns
maximum absolute value

2.9.3.44 mha_real_t MHASignal::maxabs ( const mha_wave_t & s )
Parameters
s

Input signal

Returns
maximum absolute value

2.9.3.45 mha_real_t MHASignal::max ( const mha_wave_t & s )
Parameters
s

Input signal

Returns
maximum absolute value

2.9.3.46 mha_real_t MHASignal::min ( const mha_wave_t & s )
Parameters
s

Input signal

Returns
maximum absolute value

2.9.3.47 mha_real_t MHASignal::sumsqr_channel ( const mha_wave_t & s, unsigned int channel )
Parameters
s

Input signal

channel

Channel

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52
Returns
P

CONTENTS

x2

2.9.3.48 mha_real_t MHASignal::sumsqr_frame ( const mha_wave_t & s, unsigned int frame )
Parameters
s

Input signal

frame

Frame number

Returns
P

x2

© 2005-2018 HörTech gGmbH, Oldenburg

2.10

Complex arithmetics in the openMHA

2.10

Complex arithmetics in the openMHA

53

Collaboration diagram for Complex arithmetics in the openMHA:

The openMHA Toolbox
library

Complex arithmetics
in the openMHA

Classes
• struct mha_complex_t
Type for complex floating point values.

Functions
• mha_complex_t & set (mha_complex_t &self, mha_real_t real, mha_real_t imag=0)
Assign real and imaginary parts to a mha_complex_t ( p. 123) variable.

• mha_complex_t mha_complex (mha_real_t real, mha_real_t imag=0)
Create a new mha_complex_t ( p. 123) with specified real and imaginary parts.

• mha_complex_t & set (mha_complex_t &self, const std::complex< mha_real_t >
&stdcomplex)
Assign a mha_complex_t ( p. 123) variable from a std::complex.

• std::complex< mha_real_t > stdcomplex (const mha_complex_t &self)
Create a std::complex from mha_complex_t ( p. 123).

• mha_complex_t & expi (mha_complex_t &self, mha_real_t angle)
replaces the value of the given mha_complex_t ( p. 123) with exp(i∗b).

• double angle (const mha_complex_t &self)
Computes the angle of a complex number in the complex plane.

• mha_complex_t & operator+= (mha_complex_t &self, const mha_complex_t &other)
Addition of two complex numbers, overwriting the first.

• mha_complex_t operator+ (const mha_complex_t &self, const mha_complex_←t &other)
Addition of two complex numbers, result is a temporary object.

• mha_complex_t & operator+= (mha_complex_t &self, mha_real_t other_real)
Addition of a complex and a real number, overwriting the complex.

• mha_complex_t operator+ (const mha_complex_t &self, mha_real_t other_real)
Addition of a complex and a real number, result is a temporary object.

• mha_complex_t & operator-= (mha_complex_t &self, const mha_complex_t &other)
Subtraction of two complex numbers, overwriting the first.
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CONTENTS

• mha_complex_t operator- (const mha_complex_t &self, const mha_complex_←t &other)
Subtraction of two complex numbers, result is a temporary object.

• mha_complex_t & operator-= (mha_complex_t &self, mha_real_t other_real)
Subtraction of a complex and a real number, overwriting the complex.

• mha_complex_t operator- (const mha_complex_t &self, mha_real_t other_real)
Subtraction of a complex and a real number, result is a temporary object.

• mha_complex_t & operator∗= (mha_complex_t &self, const mha_complex_t &other)
Multiplication of two complex numbers, overwriting the first.

• mha_complex_t operator∗ (const mha_complex_t &self, const mha_complex_←t &other)
Multiplication of two complex numbers, result is a temporary object.

• mha_complex_t & operator∗= (mha_complex_t &self, mha_real_t other_real)
Multiplication of a complex and a real number, overwriting the complex.

• mha_complex_t & expi (mha_complex_t &self, mha_real_t angle, mha_real_t factor)
replaces (!) the value of the given mha_complex_t ( p. 123) with a ∗ exp(i∗b)

• mha_complex_t operator∗ (const mha_complex_t &self, mha_real_t other_real)
Multiplication of a complex and a real number, result is a temporary object.

• mha_real_t abs2 (const mha_complex_t &self)
Compute the square of the absolute value of a complex value.

• mha_real_t abs (const mha_complex_t &self)
Compute the absolute value of a complex value.

• mha_complex_t & operator/= (mha_complex_t &self, mha_real_t other_real)
Division of a complex and a real number, overwriting the complex.

• mha_complex_t operator/ (const mha_complex_t &self, mha_real_t other_real)
Division of a complex and a real number, result is a temporary object.

• mha_complex_t & safe_div (mha_complex_t &self, const mha_complex_t &other,
mha_real_t eps, mha_real_t eps2)
Safe division of two complex numbers, overwriting the first.

• mha_complex_t & operator/= (mha_complex_t &self, const mha_complex_t &other)
Division of two complex numbers, overwriting the first.

• mha_complex_t operator/ (const mha_complex_t &self, const mha_complex_←t &other)
Division of two complex numbers, result is a temporary object.

• mha_complex_t operator- (const mha_complex_t &self)
Unary minus on a complex results in a negative temporary object.

• bool operator== (const mha_complex_t &x, const mha_complex_t &y)
Compare two complex numbers for equality.

• bool operator!= (const mha_complex_t &x, const mha_complex_t &y)
Compare two complex numbers for inequality.

• void conjugate (mha_complex_t &self)
Replace (!) the value of this mha_complex_t ( p. 123) with its conjugate.

• mha_complex_t _conjugate (const mha_complex_t &self)
Compute the cojugate of this complex value.

• void reciprocal (mha_complex_t &self)
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55

Replace the value of this complex with its reciprocal.

• mha_complex_t _reciprocal (const mha_complex_t &self)
compute the reciprocal of this complex value.

• void normalize (mha_complex_t &self)
Divide a complex by its absolute value, thereby normalizing it (projecting onto the unit circle).

• void normalize (mha_complex_t &self, mha_real_t margin)
Divide a complex by its absolute value, thereby normalizing it (projecting onto the unit circle),
with a safety margin.

• bool almost (const mha_complex_t &self, const mha_complex_t &other, mha_real_t
times_epsilon=1e2)
Compare two complex numbers for equality except for a small relative error.

• bool operator< (const mha_complex_t &x, const mha_complex_t &y)
Compares the absolute values of two complex numbers.

2.10.1

Detailed Description

2.10.2

Function Documentation

2.10.2.1 mha_complex_t& set ( mha_complex_t & self, mha_real_t real, mha_real_t imag =
0 ) [inline]
Parameters
self
real
imag

The mha_complex_t (p. 123) variable whose value is about to change.
The new real part.
The new imaginary part.

Returns
A reference to the changed variable.

2.10.2.2 mha_complex_t mha_complex ( mha_real_t real, mha_real_t imag = 0 ) [inline]
Parameters
real
imag

The real part.
The imaginary part.

Returns
The new value.
2.10.2.3 mha_complex_t& set ( mha_complex_t & self, const std::complex< mha_real_t > &
stdcomplex ) [inline]

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CONTENTS

Parameters
self
stdcomplex

The mha_complex_t (p. 123) variable whose value is about to change.
The new complex value.

Returns
A reference to the changed variable.

2.10.2.4 mha_complex_t& expi ( mha_complex_t & self, mha_real_t angle ) [inline]
Parameters
self
angle

The mha_complex_t (p. 123) variable whose value is about to change.
The angle in the complex plane [rad].

Returns
A reference to the changed variable.

2.10.2.5

double angle ( const mha_complex_t & self ) [inline]

Parameters
The complex number whose angle is needed.

self

Returns
The angle of a complex number in the complex plane.

2.10.2.6 mha_complex_t& expi ( mha_complex_t & self, mha_real_t angle, mha_real_t
factor ) [inline]
Parameters
self
angle

The mha_complex_t (p. 123) variable whose value is about to change.
The imaginary exponent.

factor

The absolute value of the result.

Returns
A reference to the changed variable.

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2.10.2.7 mha_real_t abs2 ( const mha_complex_t & self ) [inline]
Returns
The square of the absolute value of self.

2.10.2.8 mha_real_t abs ( const mha_complex_t & self ) [inline]
Returns
The absolute value of self.

2.10.2.9 mha_complex_t& safe_div ( mha_complex_t & self, const mha_complex_t & other,
mha_real_t eps, mha_real_t eps2 ) [inline]
If abs(divisor) < eps, then divisor is replaced by eps. eps2 = eps∗eps.
2.10.2.10 mha_complex_t _conjugate ( const mha_complex_t & self ) [inline]
Returns
A temporary object holding the conjugate value.

2.10.2.11 mha_complex_t _reciprocal ( const mha_complex_t & self ) [inline]
Returns
A temporary object holding the reciprocal value.

2.10.2.12

bool almost ( const mha_complex_t & self, const mha_complex_t & other,
mha_real_t times_epsilon = 1e2 ) [inline]

Parameters
self
other
times_epsilon

The first complex number.
The second complex number.
Permitted relative error is this number multiplied with the machine accuracy
for this Floating point format (std::numeric_limits::epsilon)

Returns
true if the relative difference is below times_epsilon ∗ std::numeric_limits←::epsilon

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2.11

CONTENTS

Fast Fourier Transform functions

Collaboration diagram for Fast Fourier Transform functions:

The openMHA Toolbox
library

Fast Fourier Transform
functions

Typedefs
• typedef void ∗ mha_fft_t
Handle for an FFT object.

Functions
• mha_fft_t mha_fft_new (unsigned int n)
Create a new FFT handle.

• void mha_fft_free (mha_fft_t h)
Destroy an FFT handle.

• void mha_fft_wave2spec (mha_fft_t h, const mha_wave_t ∗in, mha_spec_t ∗out)
Tranform waveform segment into spectrum.

• void mha_fft_wave2spec (mha_fft_t h, const mha_wave_t ∗in, mha_spec_t ∗out, bool
swaps)
Tranform waveform segment into spectrum.

• void mha_fft_spec2wave (mha_fft_t h, const mha_spec_t ∗in, mha_wave_t ∗out)
Tranform spectrum into waveform segment.

• void mha_fft_spec2wave (mha_fft_t h, const mha_spec_t ∗in, mha_wave_t ∗out, unsigned int offset)
Tranform spectrum into waveform segment.

• void mha_fft_forward (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (forward).

• void mha_fft_backward (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (backward).

• void mha_fft_forward_scale (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (forward).

• void mha_fft_backward_scale (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (backward).

• void mha_fft_wave2spec_scale (mha_fft_t h, const mha_wave_t ∗in, mha_spec_←t ∗out)
Tranform waveform segment into spectrum.

• void mha_fft_spec2wave_scale (mha_fft_t h, const mha_spec_t ∗in, mha_wave_←t ∗out)
Tranform spectrum into waveform segment.
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2.11

Fast Fourier Transform functions

2.11.1

Detailed Description

2.11.2

Typedef Documentation

2.11.2.1

59

typedef void∗ mha_fft_t

This FFT object is used by the functions mha_fft_wave2spec and mha_fft_spec2wave. The F←FT back-end is the FFTW library. The back-end is completely hidden, including external header
files or linking external libraries is not required.

2.11.3

Function Documentation

2.11.3.1 mha_fft_t mha_fft_new ( unsigned int n )
Parameters
n

FFT length.

Create a new FFT handle.
Parameters
n

FFT length

Return values
FFT

2.11.3.2

object

void mha_fft_free ( mha_fft_t h )

Parameters
h

Handle to be destroyed.

Destroy an FFT handle.
Parameters
h

FFT object to be removed

2.11.3.3

void mha_fft_wave2spec ( mha_fft_t h, const mha_wave_t ∗ in, mha_spec_t ∗ out )

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Parameters
h
in

FFT handle.
Input waveform segment.

out

Output spectrum.

Tranform waveform segment into spectrum.
Parameters
h

FFT object handle

in

pointer to input waveform signal

out

pointer to output spectrum signal (has to be allocated)

void mha_fft_wave2spec ( mha_fft_t h, const mha_wave_t ∗ in, mha_spec_t ∗ out, bool
swaps )

2.11.3.4

Like normal wave2spec, but swaps wave buffer halves before transforming if the swaps parameter is true.
Warning: These openMHA FFTs adopt a nonstandard scaling scheme in which the forward
transform scales by 1/N and the backward does not scale. We would recommend using the
'_scale' methods instead.
Parameters
h
in

FFT handle.
Input waveform segment.

out

Output spectrum.

swaps

Function swaps the first and second half of the waveform buffer before the FFT
transform when this parameter is set to true.

2.11.3.5

void mha_fft_spec2wave ( mha_fft_t h, const mha_spec_t ∗ in, mha_wave_t ∗ out )

Warning: These openMHA FFTs adopt a nonstandard scaling scheme in which the forward
transform scales by 1/N and the backward does not scale. We would recommend using the
'_scale' methods instead.
Parameters
h
in

FFT handle.
Input spectrum.

out

Output waveform segment.

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Tranform spectrum into waveform segment.
Parameters
h
in

FFT object handle
pointer to input spectrum

out

pointer to output waveform signal (has to be allocated)

2.11.3.6

void mha_fft_spec2wave ( mha_fft_t h, const mha_spec_t ∗ in, mha_wave_t ∗ out,
unsigned int offset )

out may have fewer number of frames than needed for a complete iFFT. Only as many frames
are written into out as fit, starting with offset offset of the complete iFFT.
Warning: These openMHA FFTs adopt a nonstandard scaling scheme in which the forward
transform scales by 1/N and the backward does not scale. We would recommend using the
'_scale' methods instead.
Parameters
h
in

FFT handle.
Input spectrum.

out

Output waveform segment.

offset

Offset into iFFT wave buffer

Tranform spectrum into waveform segment.
Only part of the iFFT is tranferred into the out buffer.
Out may have fewer number of freames than needed for a complete iFFT. Only as many frames
are written into out as fit, starting with offset offset of the complete iFFT.
Parameters
h
in

FFT object handle
pointer to input spectrum

out

pointer to output waveform signal (has to be allocated)

offset

Offset into complete iFFT buffer.

2.11.3.7

void mha_fft_forward ( mha_fft_t h, mha_spec_t ∗ sIn, mha_spec_t ∗ sOut )

sIn and sOut need to have nfft bins (please note that mha_spec_t (p. 141) typically has nfft/2+1
bins for half-complex representation).
Warning: These openMHA FFTs adopt a nonstandard scaling scheme in which the forward
transform scales by 1/N and the backward does not scale. We would recommend using the
'_scale' methods instead.
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Parameters
h
sIn

FFT handle.
Input spectrum.

sOut

Output spectrum.

2.11.3.8

void mha_fft_backward ( mha_fft_t h, mha_spec_t ∗ sIn, mha_spec_t ∗ sOut )

sIn and sOut need to have nfft bins (please note that mha_spec_t (p. 141) typically has nfft/2+1
bins for half-complex representation).
Warning: These openMHA FFTs adopt a nonstandard scaling scheme in which the forward
transform scales by 1/N and the backward does not scale. We would recommend using the
'_scale' methods instead.
Parameters
h
sIn

FFT handle.
Input spectrum.

sOut

Output spectrum.

2.11.3.9

void mha_fft_forward_scale ( mha_fft_t h, mha_spec_t ∗ sIn, mha_spec_t ∗ sOut )

sIn and sOut need to have nfft bins (please note that mha_spec_t (p. 141) typically has nfft/2+1
bins for half-complex representation).
The _scale methods use standard DFT scaling: There is no scaling in the forward transformation, and 1/N scaling for the backward.
Parameters
h
sIn

FFT handle.
Input spectrum.

sOut

Output spectrum.

2.11.3.10

void mha_fft_backward_scale ( mha_fft_t h, mha_spec_t ∗ sIn, mha_spec_t ∗ sOut )

sIn and sOut need to have nfft bins (please note that mha_spec_t (p. 141) typically has nfft/2+1
bins for half-complex representation).
The _scale methods use standard DFT scaling: There is no scaling in the forward transformation, and 1/N scaling for the backward.

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Parameters
h
sIn

FFT handle.
Input spectrum.

sOut

Output spectrum.

2.11.3.11

void mha_fft_wave2spec_scale ( mha_fft_t h, const mha_wave_t ∗ in, mha_spec_t ∗
out )

The _scale methods use standard DFT scaling: There is no scaling in the forward transformation, and 1/N scaling for the backward.
Parameters
h
in

FFT handle.
Input waveform segment.

out

Output spectrum.

2.11.3.12

void mha_fft_spec2wave_scale ( mha_fft_t h, const mha_spec_t ∗ in, mha_wave_t ∗
out )

The _scale methods use standard DFT scaling: There is no scaling in the forward transformation, and 1/N scaling for the backward.
Parameters
h
in

FFT handle.
Input spectrum.

out

Output waveform segment.

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3

CONTENTS

Namespace Documentation

3.1

AuditoryProfile Namespace Reference

Namespace for classes and functions around the auditory profile (e.g., audiogram handling)

Classes
• class fmap_t
A class to store frequency dependent data (e.g., HTL and UCL).

• class parser_t
Class to make the auditory profile accessible through the parser interface.

• class profile_t
The Auditory Profile class.

3.1.1

Detailed Description

The auditory profile as defined by HearCom or BMBF Modellbasierte Hoergeraete is stored in
the class AuditoryProfile::profile_t (p. 94). Until a complete definition is available, only the
currently needed elements are implemented.

3.2

DynComp Namespace Reference

dynamic compression related classes and functions

Classes
• class dc_afterburn_rt_t
Real-time class for after burn effect.

• class dc_afterburn_t
Afterburn class, to be defined as a member of compressors.

• class dc_afterburn_vars_t
Variables for dc_afterburn_t ( p. 97) class.

• class gaintable_t
Gain table class.
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Functions
• mha_real_t interp1 (const std::vector< mha_real_t > &vX, const std::vector< mha_←real_t > &vY, mha_real_t X)
One-dimensional linear interpolation.

• mha_real_t interp2 (const std::vector< mha_real_t > &vX, const std::vector< mha←_real_t > &vY, const std::vector< std::vector< mha_real_t > > &mZ, mha_real_t X,
mha_real_t Y)
Linear interpolation in a two-dimensional field.

3.2.1

Function Documentation

3.2.1.1 mha_real_t DynComp::interp1 ( const std::vector< mha_real_t > & vX, const std::vector<
mha_real_t > & vY, mha_real_t X )
Parameters
vX
vY
X

Vector with input samples.
Vector with values at input samples.
Input value to be interpolated.

Return values
Interpolated

value Y(X) at position X.

3.2.1.2 mha_real_t DynComp::interp2 ( const std::vector< mha_real_t > & vX, const std::vector<
mha_real_t > & vY, const std::vector< std::vector< mha_real_t > > & mZ, mha_real_t
X, mha_real_t Y )
Parameters
vX
vY
mZ

Vector with input samples, first dimension.
Vector with input samples, second dimension.
Field with values at input samples.

X

First dimension of input value to be interpolated.

Y

Second dimension of input value to be interpolated.

Return values
Interpolated

value Z(X,Y) at position X,Y.

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CONTENTS

MHA_AC Namespace Reference

Functions and classes for Algorithm Communication (AC) support.

Classes
• class ac2matrix_t
Copy AC variable to a matrix.

• class acspace2matrix_t
Copy all or a subset of all numeric AC variables into an array of matrixes.

• class double_t
Insert a double precision floating point variable into the AC space.

• class float_t
Insert a float point variable into the AC space.

• class int_t
Insert a integer variable into the AC space.

• class spectrum_t
Insert a MHASignal::spectrum_t ( p. 261) class into the AC space.

• class waveform_t
Insert a MHASignal::waveform_t ( p. 268) class into the AC space.

Functions
• mha_spec_t get_var_spectrum (algo_comm_t ac, const std::string &name)
Convert an AC variable into a spectrum.

• mha_wave_t get_var_waveform (algo_comm_t ac, const std::string &name)
Convert an AC variable into a waveform.

• int get_var_int (algo_comm_t ac, const std::string &name)
Return value of an integer scalar AC variable.

• float get_var_float (algo_comm_t ac, const std::string &name)
Return value of an floating point scalar AC variable.

• std::vector< float > get_var_vfloat (algo_comm_t ac, const std::string &name)
Return value of an floating point vector AC variable as standard vector of floats.

3.3.1

3.4

Detailed Description

MHA_TCP Namespace Reference

A Namespace for TCP helper classes.
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MHAEvents Namespace Reference

67

Classes
• class Async_Notify
Portable Multiplexable cross-thread notification.

• class Client
A portable class for a tcp client connections.

• class Connection
Connection ( p. 144) handles Communication between client and server, is used on both sides.

• class Event_Watcher
OS-independent event watcher, uses select on Unix and WaitForMultipleObjects on Windows.

• class Sockread_Event
Watch socket for incoming data.

• class Thread
A very simple class for portable threads.

• class Timeout_Watcher
OS-independent event watcher with internal fixed-end-time timeout.

• class Wakeup_Event
A base class for asynchronous wakeup events.

Functions
• std::string STRERROR (int err)
Portable conversion from error number to error string.

• std::string HSTRERROR (int err)
Portable conversion from hostname error number to error string.

• int N_ERRNO ()
Portable access to last network error number.

• int H_ERRNO ()
Portable access to last hostname error number.

• int G_ERRNO ()
Portable access to last non-network error number.

• double dtime ()
Time access function for system's high resolution time, retrieve current time as double.

• double dtime (const struct timeval &tv)
Time access function for unix' high resolution time, converts struct timeval to double.

• struct timeval stime (double d)
Time access function for unix' high resolution time, converts time from double to struct timeval.

3.5

MHAEvents Namespace Reference

Collection of event handling classes.
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Classes
• class emitter_t
Class for emitting openMHA events.

• class patchbay_t
Patchbay which connects any event emitter with any member function of the parameter class.

3.6

MHAFilter Namespace Reference

Namespace for IIR and FIR filter classes.

Classes
• class adapt_filter_t
Adaptive filter.

• class blockprocessing_polyphase_resampling_t
A class that does polyphase resampling and takes into account block processing.

• class complex_bandpass_t
Complex bandpass filter.

• class diff_t
Differentiator class (non-normalized)

• class fftfilter_t
FFT based FIR filter implementation.

• class fftfilterbank_t
FFT based FIR filterbank implementation.

• class filter_t
Generic IIR filter class.

• class gamma_flt_t
Class for gammatone filter.

• class iir_filter_t
IIR filter class wrapper for integration into parser structure.

• class iir_ord1_real_t
First order recursive filter.

• class o1_ar_filter_t
First order attack-release lowpass filter.

• class o1flt_lowpass_t
First order low pass filter.

• class o1flt_maxtrack_t
First order maximum tracker.

• class o1flt_mintrack_t
First order minimum tracker.

• class partitioned_convolution_t
A filter class for partitioned convolution.
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69

• class polyphase_resampling_t
A class that does polyphase resampling.

• class resampling_filter_t
Hann shaped low pass filter for resampling.

• class smoothspec_t
Smooth spectral gains, create a windowed impulse response.

• struct transfer_function_t
a structure containing a source channel number, a target channel number, and an impulse
response.

• struct transfer_matrix_t
A sparse matrix of transfer function partitionss.

Functions
• void o1_lp_coeffs (const mha_real_t tau, const mha_real_t fs, mha_real_t &c1, mha←_real_t &c2)
Set first order filter coefficients from time constant and sampling rate.

• void butter_stop_ord1 (double ∗A, double ∗B, double f1, double f2, double fs)
Setup a first order butterworth band stop filter.

• MHASignal::waveform_t ∗ spec2fir (const mha_spec_t ∗spec, const unsigned int fftlen,
const MHAWindow::base_t &window, const bool minphase)
Create a windowed impulse response/FIR filter coefficients from a spectrum.

• unsigned gcd (unsigned a, unsigned b)
greatest common divisor

• double sinc (double x)
sin(x)/x function, coping with x=0.

• std::pair< unsigned, unsigned > resampling_factors (float source_sampling_rate, float
target_sampling_rate, float factor=1.0f)
Computes rational resampling factor from two sampling rates.

3.6.1
3.6.1.1

Function Documentation
void MHAFilter::o1_lp_coeffs ( const mha_real_t tau, const mha_real_t fs, mha_real_t &
c1, mha_real_t & c2 )

Parameters
tau
fs

Time constant
Sampling rate

Return values
c1
c2

Recursive filter coefficient
Non-recursive filter coefficient

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void MHAFilter::butter_stop_ord1 ( double ∗ A, double ∗ B, double f1, double f2, double fs )

3.6.1.2

This function calculates the filter coefficients of a first order butterworth band stop filter.
Return values
A
B

recursive filter coefficients
non recursive filter coefficients

Parameters
f1

lower frequency

f2

upper frequency

fs

sample frequency

3.6.1.3 MHASignal::waveform_t ∗ MHAFilter::spec2fir ( const mha_spec_t ∗ spec, const
unsigned int fftlen, const MHAWindow::base_t & window, const bool minphase )
Parameters
spec

Input spectrum

fftlen

FFT length of spectrum

window

Window shape (with length, e.g. initialized with MHAWindow::hanning(54)).

minphase

Flag, true if original phase should be discarded and replaced by a minimal
phase function.

3.6.1.4

double MHAFilter::sinc ( double x )

This is the historical sinc function, not the normalized sinc function.
3.6.1.5

std::pair< unsigned, unsigned > MHAFilter::resampling_factors ( float source_sampling_rate,
float target_sampling_rate, float factor = 1.0f )

The function will fail if either sampling_rate ∗ factor is not an integer
Parameters
source_sampling_rate
target_sampling_rate

The original sampling rate
The desired sampling rate

factor

A helper factor to use for non-integer sampling rates

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MHAIOJack Namespace Reference

71

Returns
a pair that contains first the upsampling factor and second the downsampling factor required for the specified resampling.
Exceptions
MHA_Error ( p. 132)

3.7

if no rational resampling factor can be found.

MHAIOJack Namespace Reference

JACK IO.

Classes
• class io_jack_t
Main class for JACK IO.

3.8

MHAJack Namespace Reference

Classes and functions for openMHA and JACK interaction.

Classes
• class client_avg_t
Generic JACK client for averaging a system response across time.

• class client_noncont_t
Generic client for synchronous playback and recording of waveform fragments.

• class client_t
Generic asynchronous JACK client.

• class port_t
Class for one channel/port.
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Functions
• void io (mha_wave_t ∗s_out, mha_wave_t ∗s_in, const std::string &name, const std←::vector< std::string > &p_out, const std::vector< std::string > &p_in, float ∗srate=NULL,
unsigned int ∗fragsize=NULL, bool use_jack_transport=false)
Functional form of generic client for synchronous playback and recording of waveform fragments.

• std::vector< unsigned int > get_port_capture_latency (const std::vector< std::string >
&ports)
Return the JACK port latency of ports.

• std::vector< int > get_port_capture_latency_int (const std::vector< std::string >
&ports)
Return the JACK port latency of ports.

• std::vector< unsigned int > get_port_playback_latency (const std::vector< std::string
> &ports)
Return the JACK port latency of ports.

3.8.1

Function Documentation

3.8.1.1

std::vector< unsigned int > MHAJack::get_port_capture_latency ( const std::vector<
std::string > & ports )

Parameters
ports

Ports to be tested

Returns
Latency vector (one entry for each port)

3.8.1.2

std::vector< int > MHAJack::get_port_capture_latency_int ( const std::vector< std::string > &
ports )

Parameters
ports

Ports to be tested

Returns
Latency vector (one entry for each port)

3.8.1.3

std::vector< unsigned int > MHAJack::get_port_playback_latency ( const std::vector<
std::string > & ports )

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MHAMultiSrc Namespace Reference

73

Parameters
ports

Ports to be tested

Returns
Latency vector (one entry for each port)

3.9

MHAMultiSrc Namespace Reference

Collection of classes for selecting audio chunks from multiple sources.

Classes
• class base_t
Base class for source selection.

3.9.1

Detailed Description

3.10

MHAOvlFilter Namespace Reference

Namespace for overlapping FFT based filter bank classes and functions.

Namespaces
• FreqScaleFun
Transform functions from linear scale in Hz to new frequency scales.

• ShapeFun
Shape functions for overlapping filters.

Classes
• class fftfb_t
FFT based overlapping filter bank.

• class fftfb_vars_t
Set of configuration variables for FFT-based overlapping filters.

• class fspacing_t
Class for frequency spacing, used by filterbank shape generator class.

• class overlap_save_filterbank_t
A time-domain minimal phase filter bank with frequency shapes from MHAOvlFilter::fftfb_t
( p. 196).
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CONTENTS

MHAOvlFilter::FreqScaleFun Namespace Reference

Transform functions from linear scale in Hz to new frequency scales.

Functions
• mha_real_t hz2hz (mha_real_t x)
Dummy scale transformation Hz to Hz.

• mha_real_t hz2bark (mha_real_t x)
Transformation to bark scale.

• mha_real_t hz2log (mha_real_t x)
Third octave frequency scale.

3.11.1

Function Documentation

3.11.1.1 mha_real_t MHAOvlFilter::FreqScaleFun::hz2hz ( mha_real_t x )
This function implements a dummy scale transformation (linear frequency scale).
Parameters
x

Input frequency in Hz

Returns
Frequency in Hz

3.11.1.2 mha_real_t MHAOvlFilter::FreqScaleFun::hz2bark ( mha_real_t x )
This function implements a critical band rate (bark) scale.
Parameters
x

Input frequency in Hz

Returns
Critical band rate in Bark
3.11.1.3 mha_real_t MHAOvlFilter::FreqScaleFun::hz2log ( mha_real_t x )
This function implements a third octave scale. Frequencies below 16 Hz are mapped to 16 Hz.

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MHAOvlFilter::ShapeFun Namespace Reference

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Parameters
Frequency in Hz

x

Returns
Third octaves relative to 1000 Hz

3.12

MHAOvlFilter::ShapeFun Namespace Reference

Shape functions for overlapping filters.

Functions
• mha_real_t rect (mha_real_t x)
Filter shape function for rectangular filters.

• mha_real_t linear (mha_real_t x)
Filter shape function for sawtooth filters.

• mha_real_t hann (mha_real_t x)
Filter shape function for hanning shaped filters.

3.12.1

Function Documentation

3.12.1.1 mha_real_t MHAOvlFilter::ShapeFun::rect ( mha_real_t x )
This function creates rectangular filter shapes. The edge is exactly half way between two center
frequencies (on a given scale).
Parameters
x

Input value in the range [-1,1].

Returns
Weigth function in the range [0,1]
3.12.1.2 mha_real_t MHAOvlFilter::ShapeFun::linear ( mha_real_t x )
This function creates sawtooth filter shapes. They rise linearly form 0 to 1 in the interval from
the lower neighbor center frequency to the band center frequency and from 1 to 0 in the interval
from the band center frequency to the upper neighbour band center frequency. Linear means
linear on a given frequency scale.

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Parameters
Input value in the range [-1,1].

x

Returns
Weigth function in the range [0,1]

3.12.1.3 mha_real_t MHAOvlFilter::ShapeFun::hann ( mha_real_t x )
This function creates hanning window shaped filters.
Parameters
Input value in the range [-1,1].

x

Returns
Weigth function in the range [0,1]

3.13

MHAParser Namespace Reference

Name space for the openMHA-Parser configuration language.

Namespaces
• StrCnv
String converter namespace.

Classes
• class base_t
Base class for all parser items.

• class bool_mon_t
Monitor with string value.

• class bool_t
Variable with a boolean value ("yes"/"no")

• class commit_t
Parser variable with event-emission functionality.

• class complex_mon_t
Monitor with complex value.
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MHAParser Namespace Reference

• class complex_t
Variable with complex value.

• class float_mon_t
Monitor with float value.

• class float_t
Variable with float value.

• class int_mon_t
Monitor variable with int value.

• class int_t
Variable with integer value.

• class keyword_list_t
Keyword list class.

• class kw_t
Variable with keyword list value.

• class mcomplex_mon_t
Matrix of complex numbers monitor.

• class mcomplex_t
Matrix variable with complex value.

• class mfloat_mon_t
Matrix of floats monitor.

• class mfloat_t
Matrix variable with float value.

• class mhapluginloader_t
Class to create a plugin loader in a parser, including the load logic.

• class monitor_t
Base class for monitors and variable nodes.

• class parser_t
Parser node class.

• class range_var_t
Base class for all variables with a numeric value range.

• class string_mon_t
Monitor with string value.

• class string_t
Variable with a string value.

• class variable_t
Base class for variable nodes.

• class vcomplex_mon_t
Monitor with vector of complex values.

• class vcomplex_t
Vector variable with complex value.

• class vfloat_mon_t
Vector of floats monitor.

• class vfloat_t
Vector variable with float value.

• class vint_mon_t
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Vector of ints monitor.

• class vint_t
Variable with vector value.

• class vstring_mon_t
Vector of monitors with string value.

• class vstring_t
Vector variable with string values.

• class window_t
MHA configuration interface for a window function generator.

Functions
• void strreplace (std::string &, const std::string &, const std::string &)
string replace function

3.13.1

Detailed Description

This namespace contains all classes which are needed for the implementation of the open←MHA configuration language. For details on the script language itself please see section The
openMHA configuration language (p. 33).

3.13.2

List of valid MHAParser items

• Sub-parser: parser_t (p. 220)
• Variables:
Numeric variables: int_t (p. 211), vint_t (p. 232), float_t (p. 208), vfloat_t (p. 229),
mfloat_t (p. 218)
Other variables: string_t (p. 225), vstring_t (p. 234), kw_t (p. 214), bool_t (p. 204)
• Monitors:
Numeric monitors: int_mon_t (p. 210), vint_mon_t (p. 231), float_mon_t (p. 207),
vfloat_mon_t (p. 228)
mfloat_mon_t (p. 217)
mcomplex_mon_t (p. 215)
Other monitors: bool_mon_t (p. 203), string_mon_t (p. 224), vstring_mon_t (p. 233)
Members can be inserted into the configuration namespace by using MHAParser::insert_item()
or the insert_member() (p. 296) macro.

3.13.3
3.13.3.1

Function Documentation
void MHAParser::strreplace ( std::string & s, const std::string & arg, const std::string & rep )

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MHAParser::StrCnv Namespace Reference

79

Parameters
s
arg
rep

3.14

target string
search pattern
replace pattern

MHAParser::StrCnv Namespace Reference

String converter namespace.

Functions
• int num_brackets (const std::string &s)
Return number of brackets at beginning and end of string.

• void str2val (const std::string &, bool &)
Convert from string.

• void str2val (const std::string &, float &)
Convert from string.

• void str2val (const std::string &, mha_complex_t &)
Convert from string.

• void str2val (const std::string &, int &)
Convert from string.

• void str2val (const std::string &, keyword_list_t &)
Convert from string.

• void str2val (const std::string &, std::string &)
Convert from string.

• template
void str2val (const std::string &s, std::vector< arg_t > &val)
Converter for vector types.

• template<>
void str2val< mha_real_t > (const std::string &s, std::vector< mha_real_t > &v)
Converter for vector with Matlab-style expansion.

• template
void str2val (const std::string &s, std::vector< std::vector< arg_t > > &val)
Converter for matrix types.

• std::string val2str (const bool &)
Convert to string.

• std::string val2str (const float &)
Convert to string.

• std::string val2str (const mha_complex_t &)
Convert to string.

• std::string val2str (const int &)
Convert to string.

• std::string val2str (const keyword_list_t &)
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Convert to string.

• std::string val2str (const std::string &)
Convert to string.

• std::string val2str (const std::vector< float > &)
Convert to string.

• std::string val2str (const std::vector< mha_complex_t > &)
Convert to string.

• std::string val2str (const std::vector< int > &)
Convert to string.

• std::string val2str (const std::vector< std::string > &)
Convert to string.

• std::string val2str (const std::vector< std::vector< float > > &)
Convert to string.

• std::string val2str (const std::vector< std::vector< mha_complex_t > > &)
Convert to string.

3.14.1

Detailed Description

The functions defined in this namespace manage the conversions from C++ variables to strings
and back. It was tried to keep a matlab compatible string format for vectors and vectors of
vectors.

3.14.2

Function Documentation

3.14.2.1

int MHAParser::StrCnv::num_brackets ( const std::string & s )

Parameters
String

s

Returns
Number of brackets, or -1 for empty string

3.15

MHAPlugin Namespace Reference

Namespace for openMHA plugin class templates and thread-safe runtime configurations.
Classes
• class config_t
Template class for thread safe configuration.

• class plugin_t
The template class for C++ openMHA plugins.
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MHASignal Namespace Reference

3.16

MHASignal Namespace Reference

81

Namespace for audio signal handling and processing classes.

Classes
• class async_rmslevel_t
Class for asynchronous level metering.

• class delay_t
Class to realize a simple delay of waveform streams.

• class delay_wave_t
Delayline containing wave fragments.

• class doublebuffer_t
Double-buffering class.

• class hilbert_t
Hilbert transformation of a waveform segment.

• class loop_wavefragment_t
Copy a fixed waveform fragment to a series of waveform fragments of other size.

• class matrix_t
n-dimensional matrix with real or complex floating point values.

• class minphase_t
Minimal phase function.

• class quantizer_t
Simple simulation of fixpoint quantization.

• class ringbuffer_t
A ringbuffer class for time domain audio signal, which makes no assumptions with respect to
fragment size.

• class schroeder_t
Schroeder tone complex class.

• class spectrum_t
a signal processing class for spectral data (based on mha_spec_t ( p. 141))

• class subsample_delay_t
implements subsample delay in spectral domain.

• class uint_vector_t
Vector of unsigned values, used for size and index description of n-dimensional matrixes.

• class waveform_t
signal processing class for waveform data (based on mha_wave_t ( p. 154))
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Functions
• void for_each (mha_wave_t ∗s, mha_real_t(∗fun)(mha_real_t))
Apply a function to each element of a mha_wave_t ( p. 154).

• mha_real_t lin2db (mha_real_t x)
Conversion from linear scale to dB (no SPL reference)

• mha_real_t db2lin (mha_real_t x)
Conversion from dB scale to linear (no SPL reference)

• mha_real_t pa2dbspl (mha_real_t x)
Conversion from linear Pascal scale to dB SPL.

• mha_real_t pa22dbspl (mha_real_t x, mha_real_t eps=1e-20f)
Conversion from squared Pascal scale to dB SPL.

• mha_real_t dbspl2pa (mha_real_t x)
Conversion from dB SPL to linear Pascal scale.

• mha_real_t smp2sec (mha_real_t n, mha_real_t srate)
conversion from samples to seconds

• mha_real_t sec2smp (mha_real_t sec, mha_real_t srate)
conversion from seconds to samples

• mha_real_t bin2freq (mha_real_t bin, unsigned fftlen, mha_real_t srate)
conversion from fft bin index to frequency

• mha_real_t freq2bin (mha_real_t freq, unsigned fftlen, mha_real_t srate)
conversion from frequency to fft bin index

• mha_real_t smp2rad (mha_real_t samples, unsigned bin, unsigned fftlen)
conversion from delay in samples to phase shift

• mha_real_t rad2smp (mha_real_t phase_shift, unsigned bin, unsigned fftlen)
conversion from phase shift to delay in samples

• template
std::vector< elem_type > dupvec (std::vector< elem_type > vec, unsigned n)
Duplicate last vector element to match desired size.

• template
std::vector< elem_type > dupvec_chk (std::vector< elem_type > vec, unsigned n)
Duplicate last vector element to match desired size, check for dimension.

• void copy_channel (mha_spec_t &self, const mha_spec_t &src, unsigned sch, unsigned dch)
Copy one channel of a source signal.

• void copy_channel (mha_wave_t &self, const mha_wave_t &src, unsigned src_←channel, unsigned dest_channel)
Copy one channel of a source signal.

• mha_real_t rmslevel (const mha_spec_t &s, unsigned int channel, unsigned int fftlen)
Return RMS level of a spectrum channel.

• mha_real_t colored_intensity (const mha_spec_t &s, unsigned int channel, unsigned
int fftlen, mha_real_t sqfreq_response[ ])
Colored spectrum intensity.

• mha_real_t maxabs (const mha_spec_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t rmslevel (const mha_wave_t &s, unsigned int channel)
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Return RMS level of a waveform channel.

• mha_real_t maxabs (const mha_wave_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t maxabs (const mha_wave_t &s)
Find maximal absolute value.

• mha_real_t max (const mha_wave_t &s)
Find maximal value.

• mha_real_t min (const mha_wave_t &s)
Find minimal value.

• mha_real_t sumsqr_channel (const mha_wave_t &s, unsigned int channel)
Calculate sum of squared values in one channel.

• mha_real_t sumsqr_frame (const mha_wave_t &s, unsigned int frame)
Calculate sum over all channels of squared values.

• void limit (mha_wave_t &s, const mha_real_t &min, const mha_real_t &max)
Limit the singal in the waveform buffer to the range [min, max].

• template
elem_type kth_smallest (elem_type array[ ], unsigned n, unsigned k)
Fast search for the kth smallest element of an array.

• template
elem_type median (elem_type array[ ], unsigned n)
Fast median search.

• template
elem_type mean (const std::vector< elem_type > &data, elem_type start_val)
Calculate average of elements in a vector.

• template
std::vector< elem_type > quantile (std::vector< elem_type > data, const std::vector<
elem_type > &p)
Calculate quantile of elements in a vector.

• void saveas_mat4 (const mha_spec_t &data, const std::string &varname, FILE ∗fh)
Save a openMHA spectrum as a variable in a Matlab4 file.

• void saveas_mat4 (const mha_wave_t &data, const std::string &varname, FILE ∗fh)
Save a openMHA waveform as a variable in a Matlab4 file.

• void saveas_mat4 (const std::vector< mha_real_t > &data, const std::string &varname,
FILE ∗fh)
Save a float vector as a variable in a Matlab4 file.

• void copy_permuted (mha_wave_t ∗dest, const mha_wave_t ∗src)
Copy contents of a waveform to a permuted waveform.

Variables
• unsigned long int signal_counter = 0
Signal counter to produce signal ID strings.

3.16.1
3.16.1.1

Function Documentation
void MHASignal::limit ( mha_wave_t & s, const mha_real_t & min, const mha_real_t &
max )

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Parameters
s
min
max

3.16.1.2

The signal to limit. The signal in this wave buffer is modified.
lower limit
upper limit

template elem_type MHASignal::kth_smallest ( elem_type array[ ],
unsigned n, unsigned k )

The order of elements is altered, but not completely sorted. Using the algorithm from N. Wirth,
published in "Algorithms + data structures = programs", Prentice-Hall, 1976
Parameters
array

Element array

Postcondition
The order of elements in the array is altered. array[k] then holds the result.
Parameters
n

number of elements in array

Precondition
n >= 1
Parameters
k

The k'th smalles element is returned: k = 0 returns the minimum, k = (n-1)/2 returns the
median, k=(n-1) returns the maximum

Precondition
k elem_type MHASignal::median ( elem_type array[ ], unsigned n )
[inline]

The order of elements is altered, but not completely sorted.

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85

Parameters
array

Element array

Postcondition
The order of elements in the array is altered. array[(n-1)/2] then holds the median.
Parameters
n

number of elements in array

Precondition
n >= 1

Returns
The median of the array elements

3.16.1.4

template elem_type MHASignal::mean ( const std::vector< elem_type > &
data, elem_type start_val ) [inline]

Parameters
data

Input vector

start_val

Value for initialization of the return value before sum.

Returns
The average of the vector elements

3.16.1.5

template std::vector MHASignal::quantile ( std::vector<
elem_type > data, const std::vector< elem_type > & p ) [inline]

Parameters
data

Input vector

p

Vector of probability values.

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Returns
Vector of quantiles of input data, one entry for each probability value.

3.16.1.6

void MHASignal::saveas_mat4 ( const mha_spec_t & data, const std::string & varname,
FILE ∗ fh )

Parameters
data

openMHA spectrum to be saved.

varname

Matlab variable name (Matlab4 limitations on maximal length are not checked).

fh

File handle to Matlab4 file.

3.16.1.7

void MHASignal::saveas_mat4 ( const mha_wave_t & data, const std::string & varname,
FILE ∗ fh )

Parameters
data

openMHA waveform to be saved.

varname

Matlab variable name (Matlab4 limitations on maximal length are not checked).

fh

File handle to Matlab4 file.

3.16.1.8

void MHASignal::saveas_mat4 ( const std::vector< mha_real_t > & data, const std::string &
varname, FILE ∗ fh )

Parameters
data
varname

Float vector to be saved.
Matlab variable name (Matlab4 limitations on maximal length are not checked).

fh

File handle to Matlab4 file.

3.16.1.9

void MHASignal::copy_permuted ( mha_wave_t ∗ dest, const mha_wave_t ∗ src )

Parameters
dest
src

Destination waveform
Source waveform

The total size of src and dest must be the same, num_frames and num_channels must be
exchanged in dest.

3.17

MHATableLookup Namespace Reference

Namespace for table lookup classes.
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MHAWindow Namespace Reference

Classes
• class xy_table_t
Class for interpolation with non-equidistant x values.

3.18

MHAWindow Namespace Reference

Collection of Window types.

Classes
• class bartlett_t
Bartlett window.

• class base_t
Common base for window types.

• class blackman_t
Blackman window.

• class fun_t
Generic window based on a generator function.

• class hamming_t
Hamming window.

• class hanning_t
von-Hann window

• class rect_t
Rectangular window.

• class user_t
User defined window.

Functions
• float rect (float)
Rectangular window function.

• float bartlett (float)
Bartlett window function.

• float hanning (float)
Hanning window function.

• float hamming (float)
Hamming window function.

• float blackman (float)
Blackman window function.
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CONTENTS

Class Documentation

4.1

algo_comm_t Struct Reference

A reference handle for algorithm communication variables.

Public Attributes
• void ∗ handle
AC variable control handle.

• int(∗ insert_var )(void ∗, const char ∗, comm_var_t)
Register an AC variable.

• int(∗ insert_var_int )(void ∗, const char ∗, int ∗)
Register an int as an AC variable.

• int(∗ insert_var_float )(void ∗, const char ∗, float ∗)
Register a float as an AC variable.

• int(∗ remove_var )(void ∗, const char ∗)
Remove an AC variable.

• int(∗ remove_ref )(void ∗, void ∗)
Remove all AC variable which refer to address.

• int(∗ is_var )(void ∗, const char ∗)
Test if an AC variable exists.

• int(∗ get_var )(void ∗, const char ∗, comm_var_t ∗)
Get the variable handle of an AC variable.

• int(∗ get_var_int )(void ∗, const char ∗, int ∗)
Get the value of an int AC variable.

• int(∗ get_var_float )(void ∗, const char ∗, float ∗)
Get the value of a float AC variable.

• int(∗ get_entries )(void ∗, char ∗, unsigned int)
Return a space separated list of all variable names.

• const char ∗(∗ get_error )(int)
Convert AC error codes into human readable error messages.

4.1.1

Detailed Description

This structure contains a coontrol handle and a set of function pointers for sharing variables
within one processing chain. See also section Communication between algorithms (p. 27).

4.1.2
4.1.2.1

Member Data Documentation
algo_comm_t::insert_var

This function can register a variable to be shared within one chain. If a variable of this name
exists it will be overwritten.

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algo_comm_t Struct Reference

89

Parameters
h
n

AC handle
name of variable. May not be empty. Must not contain space character. The name is
copied, therefore it is allowed that the char array pointed to gets invalid after return.

v

variable handle of type comm_var_t (p. 95)

Returns
Error code or zero on success

4.1.2.2

algo_comm_t::insert_var_int

This function can register an int variable to be shared with other algorithms. It behaves similar
to ac.insert_var.
Parameters
h
n
v

AC handle
name of variable
pointer on the variable

Returns
Error code or zero on success

4.1.2.3

algo_comm_t::insert_var_float

This function can register a float variable to be shared with other algorithms. It behaves similar
to ac.insert_var.
Parameters
h
n
v

AC handle
name of variable
pointer on the variable

Returns
Error code or zero on success
4.1.2.4

algo_comm_t::remove_var

Remove (unregister) an AC variable. After calling this function, the variable is not available to
ac.is_var or ac.get_var. The data pointer is not affected.
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Parameters
h
n

AC handle
name of variable to be removed

Returns
Error code or zero on success

4.1.2.5

algo_comm_t::remove_ref

This function removes all AC variables whos data field points to the given address.
Parameters
h
p

AC handle
address which should not be referred to any more

Returns
Error code or zero on success

4.1.2.6

algo_comm_t::is_var

This function tests if an AC variable of a given name exists. Use ac.get_var to get information
about the variables type and dimension.
Parameters
h
n

AC handle
name of variable

Returns
1 if the variable exists, 0 otherwise

4.1.2.7

algo_comm_t::get_var

This function returns the variable handle comm_var_t (p. 95) of a variable of the given name.
If no variable of that name exists, an error code is returned.

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algo_comm_t Struct Reference

91

Parameters
h
n
v

AC handle
name of variable
pointer to a AC variable object

Returns
Error code or zero on success

4.1.2.8

algo_comm_t::get_var_int

This function returns the value of an int AC variable of the given name. If no variable exists, the
variable type is mismatching or more than one entry is registered, a corresponding error code
is returned. This is a special version of ac.get_var.
Parameters
h
n
v

AC handle
name of variable
pointer on an int variable to store the result

Returns
Error code or zero on success

4.1.2.9

algo_comm_t::get_var_float

This function returns the value of a float AC variable of the given name. If no variable exists, the
variable type is mismatching or more than one entry is registered, a corresponding error code
is returned. This is a special version of ac.get_var.
Parameters
h
n
v

AC handle
name of variable
pointer on a float variable to store the result

Returns
Error code or zero on success

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4.1.2.10

CONTENTS

algo_comm_t::get_entries

This function returns the names of all registered variables, separated by a single space.

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AuditoryProfile::fmap_t Class Reference

93

Parameters
AC handle

h

Return values
ret

Character buffer for return value

Parameters
length of character buffer

len

Returns
Error code or zero on success. -1: invalid ac handle. -3: not enough room in character
buffer to store all variable names.

4.1.2.11

algo_comm_t::get_error

Parameters
e

Error code

Returns
Error message

4.2

AuditoryProfile::fmap_t Class Reference

A class to store frequency dependent data (e.g., HTL and UCL).
Inherits map< mha_real_t, mha_real_t >.

Public Member Functions
• std::vector< mha_real_t > get_frequencies () const
Return configured frequencies.

• std::vector< mha_real_t > get_values () const
Return stored values corresponding to the frequencies.
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4.3

CONTENTS

AuditoryProfile::parser_t Class Reference

Class to make the auditory profile accessible through the parser interface.
Inheritance diagram for AuditoryProfile::parser_t:

MHAParser::base_t

MHAParser::parser_t

AuditoryProfile::parser_t

Additional Inherited Members

4.4

AuditoryProfile::profile_t Class Reference

The Auditory Profile class.

Classes
• class ear_t
Class for ear-dependent parameters, e.g., audiograms or unilateral loudness scaling.

Public Member Functions
• AuditoryProfile::profile_t::ear_t get_ear (unsigned int channel) const
Return ear information of channel number.

Public Attributes
• AuditoryProfile::profile_t::ear_t L
Left ear data.

• AuditoryProfile::profile_t::ear_t R
Right ear data.
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AuditoryProfile::profile_t::ear_t Class Reference

4.4.1

95

Detailed Description

See definition of auditory profile
Currently only the audiogram data is stored.

4.5

AuditoryProfile::profile_t::ear_t Class Reference

Class for ear-dependent parameters, e.g., audiograms or unilateral loudness scaling.

4.6

comm_var_t Struct Reference

Algorithm communication variable structure.

Public Attributes
• unsigned int data_type
Type of data.

• unsigned int num_entries
Number of entries.

• unsigned int stride
length of one row (C interpretation) or of one column (Fortran interpretation)

• void ∗ data
Pointer to variable data.

4.6.1

Detailed Description

Algorithm communication variables (AC variables) are objects of this type. The member data
is a pointer to the variable ‘data'. This pointer has to be valid for the lifetime of this AC variable.
The member ‘data_type' can be one of the predefined types or any user defined type. The
member ‘num_entries' describes the number of elements of this base type stored at the pointer
address.

An AC variable can be registered with the \ref
algo_comm_t::insert_var "insert_var" function.

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4.6.2

CONTENTS

Member Data Documentation

4.6.2.1

comm_var_t::data_type

This can be one of the predefined types
• MHA_AC_CHAR
• MHA_AC_INT
• MHA_AC_MHAREAL
• MHA_AC_FLOAT
• MHA_AC_DOUBLE
• MHA_AC_MHACOMPLEX
• MHA_AC_VEC_FLOAT or any user defined type with a value greater than
• MHA_AC_USER

4.7

DynComp::dc_afterburn_rt_t Class Reference

Real-time class for after burn effect.

Public Member Functions
• void burn (float &Gin, float Lin, unsigned int band, unsigned int channel)
gain modifier method (afterburn).

4.7.1

Detailed Description

The constructor processes the parameters and creates pre-processed variables for efficient
realtime processing.

4.7.2
4.7.2.1

Member Function Documentation
void DynComp::dc_afterburn_rt_t::burn ( float & Gin, float Lin, unsigned int band, unsigned int
channel ) [inline]

Parameters
Gin

Linear gain.

Lin
band
channel

Input level (Pascal).
Filter band number.
Channel number.

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DynComp::dc_afterburn_t Class Reference

97

Output level for MPO is estimated by Gin ∗ Lin.

4.8

DynComp::dc_afterburn_t Class Reference

Afterburn class, to be defined as a member of compressors.

Inheritance diagram for DynComp::dc_afterburn_t:

MHAParser::base_t

MHAParser::parser_t

DynComp::dc_afterburn
_vars_t

MHAPlugin::config_t
< dc_afterburn_rt_t >

DynComp::dc_afterburn_t

Additional Inherited Members

4.9

DynComp::dc_afterburn_vars_t Class Reference

Variables for dc_afterburn_t (p. 97) class.
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Inheritance diagram for DynComp::dc_afterburn_vars_t:

MHAParser::base_t

MHAParser::parser_t

DynComp::dc_afterburn
_vars_t

DynComp::dc_afterburn_t

Additional Inherited Members

4.10

DynComp::gaintable_t Class Reference

Gain table class.
Public Member Functions
• gaintable_t (const std::vector< mha_real_t > &LInput, const std::vector< mha_real_t
> &FCenter, unsigned int channels)
Constructor.

• void update (std::vector< std::vector< std::vector< mha_real_t > > > newGain)
Update gains from an external table.

• mha_real_t get_gain (mha_real_t Lin, mha_real_t Fin, unsigned int channel)
Read Gain from gain table.

• mha_real_t get_gain (mha_real_t Lin, unsigned int band, unsigned int channel)
Read Gain from gain table.

• void get_gain (const mha_wave_t &Lin, mha_wave_t &Gain)
Read Gains from gain table.

• unsigned int nbands () const
Return number of frequency bands.

• unsigned int nchannels () const
Return number of audio channels.

• std::vector< std::vector< mha_real_t > > get_iofun () const
Return current input-output function.
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DynComp::gaintable_t Class Reference

4.10.1

99

Detailed Description

This gain table is intended to efficient table lookup, i.e, interpolation of levels, and optional
interpolation of frequencies. Sample input levels and sample frequencies are given in the constructor. The gain entries can be updated with the update() (p. 99) member function via a gain
prescription rule from an auditory profile.

4.10.2

Constructor & Destructor Documentation

4.10.2.1

gaintable_t::gaintable_t ( const std::vector< mha_real_t > & LInput, const std::vector<
mha_real_t > & FCenter, unsigned int channels )

Parameters
LInput

Input level samples, in equivalent LTASS_combined dB SPL.

FCenter

Frequency samples in Hz (e.g., center frequencies of filterbank).

channels

Number of audio channels (typically 2).

4.10.3
4.10.3.1

Member Function Documentation
void gaintable_t::update ( std::vector< std::vector< std::vector< mha_real_t > > >
newGain )

Parameters
newGain

New gain table entries.

Dimension change is not allowed. The number of entries are checked.
4.10.3.2 mha_real_t gaintable_t::get_gain ( mha_real_t Lin, mha_real_t Fin, unsigned int channel
)
Parameters
Lin

Input level

Fin
channel

Input frequency (no match required)
Audio channel

4.10.3.3 mha_real_t gaintable_t::get_gain ( mha_real_t Lin, unsigned int band, unsigned int
channel )

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Parameters
Lin

Input level

band
channel

Input frequency band
Audio channel

4.10.3.4

void gaintable_t::get_gain ( const mha_wave_t & Lin, mha_wave_t & Gain )

Parameters
Lin

Input levels.

Gain

Output gain.

The number of channels in Lin and Gain must match the number of bands times number of
channels in the gaintable.

4.11

expression_t Class Reference

Class for separating a string into a left hand value and a right hand value.
4.11.1

Detailed Description

A list of valid operators can be provided. After construction, the class members lval, rval and
op contain the apropriate contents.

4.12

io_file_t Class Reference

File IO.
Inheritance diagram for io_file_t:

MHAParser::base_t

MHAParser::parser_t

io_file_t

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io_lib_t Class Reference

101

Public Member Functions
• void prepare (int, int)
Allocate buffers, activate FILE client and install internal ports.

• void release ()
Remove FILE client and deallocate internal ports and buffers.

Additional Inherited Members
4.12.1

Member Function Documentation

4.12.1.1

void io_file_t::prepare ( int nch_in, int nch_out )

4.12.1.2

void io_file_t::release ( )

4.13

io_lib_t Class Reference

Class for loading MHA sound IO module.
Inherits MHAParser::c_ifc_parser_t.

Public Member Functions
• io_lib_t (int fragsize, float samplerate, IOProcessEvent_t proc_event, void ∗proc_handle,
IOStartedEvent_t start_event, void ∗start_handle, IOStoppedEvent_t stop_event, void
∗stop_handle, std::string libname)
load and initialize MHA sound io module.

• ∼io_lib_t ()
Deinitialize and unload this MHA sound io module.

• void prepare (unsigned int inch, unsigned int outch)
Prepare the sound io module.

• void start ()
Tell the sound io module to start sound processing.

4.13.1
4.13.1.1

Member Function Documentation
void io_lib_t::prepare ( unsigned int inch, unsigned int outch )

After preparation, the sound io module may start the sound processing at any time (external
trigger). When the sound processing is started, the sound io module will call the start_event
callback.

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CONTENTS

Parameters
inch

number of input channels

outch

number of output channels

4.13.1.2

void io_lib_t::start ( )

Some io modules need this, for others that wait for external events this method might do nothing.

4.14

io_parser_t Class Reference

Main class for Parser IO.
Inheritance diagram for io_parser_t:

MHAParser::base_t

MHAParser::parser_t

io_parser_t

Public Member Functions
• void prepare (int, int)
Allocate buffers, activate JACK client and install internal ports.

• void release ()
Remove JACK client and deallocate internal ports and buffers.
© 2005-2018 HörTech gGmbH, Oldenburg

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io_tcp_fwcb_t Class Reference

103

Additional Inherited Members
4.14.1

Detailed Description

4.14.2

Member Function Documentation

4.14.2.1

void io_parser_t::prepare ( int nch_in, int nch_out )

4.14.2.2

void io_parser_t::release ( )

4.15

io_tcp_fwcb_t Class Reference

TCP sound-io library's interface to the framework callbacks.

Public Member Functions
• io_tcp_fwcb_t (IOProcessEvent_t proc_event, void ∗proc_handle, IOStartedEvent_←t start_event, void ∗start_handle, IOStoppedEvent_t stop_event, void ∗stop_handle)
Constructor stores framework handles and initializes error numbers to 0.

• virtual ∼io_tcp_fwcb_t ()
Do-nothing destructor.

• virtual void start ()
Call the framework's start callback.

• virtual int process (mha_wave_t ∗sIn, mha_wave_t ∗&sOut)
Call the frameworks processing callback.

• virtual void set_errnos (int proc_err, int io_err)
Save error numbers to use during.

• virtual void stop ()
Call the frameworks stop callback.

Private Attributes
• IOProcessEvent_t proc_event
Pointer to signal processing callback function.

• IOStartedEvent_t start_event
Pointer to start notification callback function.

• IOStoppedEvent_t stop_event
Pointer to stop notification callback function.

• void ∗ proc_handle
Handles belonging to framework.

• int proc_err
Errors from the processing callback and from the TCP IO itself are stored here before closing
Network handles.
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4.15.1

Detailed Description

4.15.2

Constructor & Destructor Documentation

CONTENTS

4.15.2.1

io_tcp_fwcb_t::io_tcp_fwcb_t ( IOProcessEvent_t proc_event, void ∗ proc_handle,
IOStartedEvent_t start_event, void ∗ start_handle, IOStoppedEvent_t stop_event, void ∗
stop_handle )

4.15.2.2

virtual io_tcp_fwcb_t::∼io_tcp_fwcb_t ( ) [inline], [virtual]

4.15.3

Member Function Documentation

4.15.3.1

void io_tcp_fwcb_t::start ( ) [virtual]

4.15.3.2

int io_tcp_fwcb_t::process ( mha_wave_t ∗ sIn, mha_wave_t ∗& sOut ) [virtual]

Parameters
sIn

The input sound data just received from TCP.

sOut

A pointer to output sound data. Will point to the output sound data storage when the
callback finishes.

Returns
Status, an error number from the signal processing callback. If this is != 0, then the
connection should be closed.

4.15.3.3

void io_tcp_fwcb_t::set_errnos ( int proc_err, int io_err ) [virtual]

See also
stop (p. 105)
Parameters
proc_err

The error number from the

See also
process (p. 104) callback.
Parameters
io_err

The error number from the io library itself.
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io_tcp_parser_t Class Reference

4.15.3.4

105

void io_tcp_fwcb_t::stop ( ) [virtual]

Uses the error numbers set previously with
See also
set_errnos (p. 104).
4.15.4

Member Data Documentation

4.15.4.1

IOProcessEvent_t io_tcp_fwcb_t::proc_event [private]

4.15.4.2

IOStartedEvent_t io_tcp_fwcb_t::start_event [private]

Called when a new TCP connection is established or the user issues the start command while
there is a connection.
4.15.4.3

IOStoppedEvent_t io_tcp_fwcb_t::stop_event [private]

Called when the connection is closed.
4.15.4.4

void∗ io_tcp_fwcb_t::proc_handle [private]

4.15.4.5

int io_tcp_fwcb_t::proc_err [private]

MHAIOTCP is notified by the server when the connection has been taken down, and calls
See also
stop (p. 105) from that callback. Within stop (p. 105), these error numbers are read again
and transmitted to the framework.

4.16

io_tcp_parser_t Class Reference

The parser interface of the IOTCP library.
Inheritance diagram for io_tcp_parser_t:

MHAParser::base_t

MHAParser::parser_t

io_tcp_parser_t

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CONTENTS

Public Member Functions
• virtual const std::string & get_local_address () const
Read parser variable local_address, this is the address of the network interface that should
listen for incoming connections.

• virtual unsigned short get_local_port () const
Read parser variable local_port, this is the TCP port that should be used for incoming connections.

• virtual void set_local_port (unsigned short port)
Set parser variable local_port.

• virtual bool get_server_port_open () const
Return the status of the server port as it is known to the parser.

• virtual void set_server_port_open (bool open)
Inform the parser of the current status of the server socket.

• virtual bool get_connected () const
Return the parser's knowledge concerning wether there currently exists an established sound
data TCP connection or not.

• virtual void set_connected (bool connected)
Inform the parser about the existance of a sound data connection.

• virtual void set_new_peer (unsigned short port, const std::string &host)
Set parser monitor variables peer_port and peer_address, and calls set_connected(true).

• io_tcp_parser_t ()
Constructor initializes parser variables.

• virtual ∼io_tcp_parser_t ()
Do-nothing destructor.

Private Attributes
• MHAParser::string_t local_address
Lets the user set the local network interface to listen on.

• MHAParser::int_t local_port
Lets the user choose the local tcp port to listen on.

• MHAParser::int_mon_t server_port_open
Indicates wether the TCP server socket is currently open.

• MHAParser::int_mon_t connected
Indicator if there currently is a sound data connection over TCP.

• MHAParser::string_mon_t peer_address
Display the ip address of the currently connected sound data client.

• MHAParser::int_mon_t peer_port
Display the tcp port used by the current sound data client.

• MHAParser::string_t debug_filename
filename to write debugging info to (if non-empty)

• FILE ∗ debug_file
file handle to write debugging info to
© 2005-2018 HörTech gGmbH, Oldenburg

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io_tcp_parser_t Class Reference

107

Additional Inherited Members
4.16.1

Detailed Description

4.16.2

Constructor & Destructor Documentation

4.16.2.1

io_tcp_parser_t::io_tcp_parser_t ( )

4.16.2.2

virtual io_tcp_parser_t::∼io_tcp_parser_t ( ) [inline], [virtual]

4.16.3

Member Function Documentation

4.16.3.1

virtual const std::string& io_tcp_parser_t::get_local_address (
[virtual]

) const [inline],

Returns
A string containing the address of the local interface as it was set by the user.

4.16.3.2

unsigned short io_tcp_parser_t::get_local_port ( ) const [virtual]

Returns
The local tcp port to listen on as it was chosen by the user. The port number is between
MIN_TCP_PORT and MAX_TCP_PORT.

4.16.3.3

void io_tcp_parser_t::set_local_port ( unsigned short port ) [virtual]

This is needed when it was set to 0 before: In this case, the OS chooses a free port for the TCP
server socket, and the port that it chose has to be published to the user via the parser interface.
Parameters
The TCP port number that is currently used. In the range [MIN_TCP_PORT,
MAX_TCP_PORT], excluding 0.

port

Precondition
get_local_port() (p. 107) currently returns 0.

4.16.3.4

bool io_tcp_parser_t::get_server_port_open ( ) const [virtual]

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CONTENTS

Returns
false after initialization, or the value most recently set via

See also
set_server_port_open (p. 108).

4.16.3.5

void io_tcp_parser_t::set_server_port_open ( bool open ) [virtual]

Parameters
open

Indicates wether the server socket has just been opened or closed.

Precondition
open may only have the value true if get_server_port_open() (p. 107) currently returns
false.

Postcondition

See also
get_server_port_open (p. 107) returns the value (p. 48) of open.

4.16.3.6

bool io_tcp_parser_t::get_connected ( ) const [virtual]

Returns
false after initialization, or the value most recently set via

See also
set_connected (p. 108).

4.16.3.7

void io_tcp_parser_t::set_connected ( bool connected ) [virtual]

Parameters
connected

Indicates wether there currently is a connection or not.

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io_tcp_parser_t Class Reference

109

Precondition
connected must not have the same value that is currently returned by

See also
get_connected (p. 108).

Postcondition

See also
get_connected (p. 108) returns the value (p. 48) of open.

4.16.3.8

void io_tcp_parser_t::set_new_peer ( unsigned short port, const std::string & host )
[virtual]

This method should be called when a new connection is established.
Parameters
port
host

The TCP port number used by the peer.
The Internet host where the peer is located.

Precondition

See also
get_connected (p. 108) currently returns false.

Postcondition

See also
get_connected (p. 108) returns true.
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4.16.4

CONTENTS

Member Data Documentation

4.16.4.1 MHAParser::string_t io_tcp_parser_t::local_address [private]
4.16.4.2 MHAParser::int_t io_tcp_parser_t::local_port [private]
4.16.4.3 MHAParser::int_mon_t io_tcp_parser_t::server_port_open [private]
4.16.4.4 MHAParser::int_mon_t io_tcp_parser_t::connected [private]
4.16.4.5 MHAParser::string_mon_t io_tcp_parser_t::peer_address [private]
4.16.4.6 MHAParser::int_mon_t io_tcp_parser_t::peer_port [private]

4.17

io_tcp_sound_t Class Reference

Sound data handling of io tcp library.

Classes
• union float_union
This union helps in conversion of floats from host byte order to network byte order and back
again.

Public Member Functions
• io_tcp_sound_t (int fragsize, float samplerate)
Initialize sound data handling.

• virtual ∼io_tcp_sound_t ()
Do-nothing destructor.

• virtual void prepare (int num_inchannels, int num_outchannels)
Called during prepare, sets number of audio channels and allocates sound data storage.

• virtual void release ()
Called during release.

• virtual int chunkbytes_in () const
Number of bytes that constitute one input sound chunk.

• virtual std::string header () const
Create the tcp sound header lines.

• virtual mha_wave_t ∗ ntoh (const std::string &data)
Copy data received from tcp into mha_wave_t ( p. 154) structure.

• virtual std::string hton (const mha_wave_t ∗s_out)
Copy sound data from the output sound structure to a string.
© 2005-2018 HörTech gGmbH, Oldenburg

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io_tcp_sound_t Class Reference

111

Static Private Member Functions
• static void check_sound_data_type ()
Check if mha_real_t is a usable 32-bit floating point type.

Private Attributes
• int fragsize
Number of sound samples in each channel expected and returned from processing callback.

• float samplerate
Sampling rate.

• int num_inchannels
Number of input channels.

• MHASignal::waveform_t ∗ s_in
Storage for input signal.

4.17.1

Constructor & Destructor Documentation

4.17.1.1

io_tcp_sound_t::io_tcp_sound_t ( int fragsize, float samplerate )

Checks sound data type by calling
See also
check_sound_data_type (p. 111).
Parameters
fragsize

Number of sound samples in each channel expected and returned from
processing callback.

samplerate

Number of samples per second in each channel.

4.17.2
4.17.2.1

Member Function Documentation
void io_tcp_sound_t::check_sound_data_type ( ) [static], [private]

Exceptions
MHA_Error ( p. 132)

if mha_real_t is not compatible to 32-bit float.

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4.17.2.2

CONTENTS

void io_tcp_sound_t::prepare ( int num_inchannels, int num_outchannels ) [virtual]

Parameters
num_inchannels

Number of input audio channels.

num_outchannels

Number of output audio channels.

4.17.2.3

void io_tcp_sound_t::release ( ) [virtual]

Deletes sound data storage.
4.17.2.4

int io_tcp_sound_t::chunkbytes_in ( ) const [virtual]

Returns
Number of bytes to read from TCP connection before invoking signal processing.

4.17.2.5

std::string io_tcp_sound_t::header ( ) const [virtual]

4.17.2.6 mha_wave_t ∗ io_tcp_sound_t::ntoh ( const std::string & data ) [virtual]
Doing network-to-host byte order swapping in the process.
Parameters
data

One chunk (

See also
chunkbytes_in (p. 112)) of sound data to process.

Returns
Pointer to the sound data storage.

4.17.2.7

std::string io_tcp_sound_t::hton ( const mha_wave_t ∗ s_out ) [virtual]

Doing host-to-network byte order swapping while at it.
Parameters
s_out

Pointer to the storage of the sound to put out.

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io_tcp_sound_t::float_union Union Reference

113

Returns
The sound data in network byte order.

4.17.3

Member Data Documentation

4.17.3.1

int io_tcp_sound_t::fragsize [private]

4.17.3.2

float io_tcp_sound_t::samplerate [private]

Number of samples per second in each channel.
4.17.3.3

int io_tcp_sound_t::num_inchannels [private]

Number of channels expected from and returned by signal processing callback.
4.17.3.4 MHASignal::waveform_t∗ io_tcp_sound_t::s_in [private]

4.18

io_tcp_sound_t::float_union Union Reference

This union helps in conversion of floats from host byte order to network byte order and back
again.

4.18.1

4.19

Detailed Description

io_tcp_t Class Reference

The tcp sound io library.

Public Member Functions
• void prepare (int num_inchannels, int num_outchannels)
Allocate server socket and start thread waiting for sound data exchange.

• void start ()
Call frameworks start callback if there is a sound data connection at the moment.

• void stop ()
Close the current connection if there is one.

• void release ()
Close the current connection and close the server socket.

• virtual void accept_loop ()
IO thread executes this method.

• virtual void connection_loop (MHA_TCP::Connection ∗c)
IO thread executes this method for each connection.

• virtual void parse (const char ∗cmd, char ∗retval, unsigned int len)
Parser interface.
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4.19.1

Detailed Description

4.19.2

Member Function Documentation

4.19.2.1

CONTENTS

void io_tcp_t::prepare ( int num_inchannels, int num_outchannels )

prepare opens the tcp server socket and starts the io thread that listens for audio data on the
tcp socket after doing some sanity checks
4.19.2.2

void io_tcp_t::start ( )

4.19.2.3

void io_tcp_t::stop ( )

stop IO thread
4.19.2.4

void io_tcp_t::release ( )

Stop IO thread and close server socket.
4.19.2.5

void io_tcp_t::accept_loop ( ) [virtual]

4.19.2.6

void io_tcp_t::connection_loop ( MHA_TCP::Connection ∗ c ) [virtual]

Parameters
c

pointer to connection. connection_loop deletes connection before exiting.

4.19.2.7

4.20

virtual void io_tcp_t::parse ( const char ∗ cmd, char ∗ retval, unsigned int len ) [inline],
[virtual]

MHA_AC::ac2matrix_t Class Reference

Copy AC variable to a matrix.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHA_AC::ac2matrix_t Class Reference

115

Inheritance diagram for MHA_AC::ac2matrix_t:

MHASignal::uint_vector_t

MHASignal::matrix_t

MHA_AC::ac2matrix_t

Public Member Functions
• ac2matrix_t (algo_comm_t ac, const std::string &name)
Constructor.

• void update ()
Update contents of the matrix from the AC space.

• const std::string & getname () const
Return name of AC variable/matrix.

• const std::string & getusername () const
Return user specified name of AC variable/matrix.

• void insert (algo_comm_t ac)
Insert matrix into an AC space (other than source AC space)

4.20.1

Detailed Description

This class constructs a matrix of same size as an AC variable and can copy the AC variable to
itself. The update() (p. 116) function is real-time safe.

4.20.2
4.20.2.1

Constructor & Destructor Documentation
MHA_AC::ac2matrix_t::ac2matrix_t ( algo_comm_t ac, const std::string & name )

Parameters
ac
name

AC handle
Name of AC variable to be copied

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4.20.3

CONTENTS

Member Function Documentation

4.20.3.1

void MHA_AC::ac2matrix_t::update ( )

This function is real-time safe. The copy operation performance is of the order of the number
of elements in the matrix.
4.20.3.2

void MHA_AC::ac2matrix_t::insert ( algo_comm_t ac )

Parameters
AC space handle to insert data

ac

Note
The AC variable data buffer points to the data of the matrix. Modifications of the AC
variable directly modify the data of the matrix; after deletion of the matrix, the data buffer
is invalid.

4.21

MHA_AC::acspace2matrix_t Class Reference

Copy all or a subset of all numeric AC variables into an array of matrixes.

Public Member Functions
• acspace2matrix_t (algo_comm_t ac, const std::vector< std::string > &names)
Constructor.

• acspace2matrix_t (const MHA_AC::acspace2matrix_t &src)
Constructor with initialization from an instance.

• MHA_AC::acspace2matrix_t & operator= (const MHA_AC::acspace2matrix_t &src)
Copy all contents (deep copy).

• MHA_AC::ac2matrix_t & operator[ ] (unsigned int k)
Access operator.

• const MHA_AC::ac2matrix_t & operator[ ] (unsigned int k) const
Constant access operator.

• void update ()
Update function.

• unsigned int size () const
Number of matrixes in AC space.

• unsigned int frame () const
Actual frame number.

• void insert (algo_comm_t ac)
Insert AC space copy into an AC space (other than source AC space)
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4.21

MHA_AC::acspace2matrix_t Class Reference

4.21.1

117

Constructor & Destructor Documentation

4.21.1.1

MHA_AC::acspace2matrix_t::acspace2matrix_t ( algo_comm_t ac, const std::vector<
std::string > & names )

Scan all given AC variables and allocate corresponding matrixes.
Parameters
AC handle.
Names of AC variables, or empty for all.

ac
names

4.21.1.2

MHA_AC::acspace2matrix_t::acspace2matrix_t ( const MHA_AC::acspace2matrix_t & src
)

Parameters
Instance to be copied.

src

4.21.2

Member Function Documentation

4.21.2.1 MHA_AC::acspace2matrix_t & MHA_AC::acspace2matrix_t::operator= ( const
MHA_AC::acspace2matrix_t & src )
Parameters
Array of matrixes to be copied.

src

4.21.2.2 MHA_AC::ac2matrix_t& MHA_AC::acspace2matrix_t::operator[ ] ( unsigned int k )
[inline]
Parameters
k

index into array; should not exceed size() (p. 116)-1.

Return values
Reference

4.21.2.3

to matrix.

const MHA_AC::ac2matrix_t& MHA_AC::acspace2matrix_t::operator[ ] ( unsigned int k )
const [inline]

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CONTENTS

Parameters
index into array; should not exceed size() (p. 116)-1.

k

Return values
Constant

4.21.2.4

reference to matrix.

void MHA_AC::acspace2matrix_t::update ( ) [inline]

This function updates all matrixes from their corresponding AC variables. It can be called from
the MHA Framework prepare function or in the processing callback.
4.21.2.5

void MHA_AC::acspace2matrix_t::insert ( algo_comm_t ac )

Parameters
AC space handle to insert data

ac

4.22

MHA_AC::double_t Class Reference

Insert a double precision floating point variable into the AC space.

Public Attributes
• double data
Floating point value variable.

4.22.1

Detailed Description

The variable is automatically removed on destruction.

4.23

MHA_AC::float_t Class Reference

Insert a float point variable into the AC space.

Public Member Functions
• float_t (algo_comm_t, std::string, float=0)
Constructor.
© 2005-2018 HörTech gGmbH, Oldenburg

4.24

MHA_AC::int_t Class Reference

119

Public Attributes
• float data
Floating point value variable.

4.23.1

Detailed Description

The variable is automatically removed on destruction.

4.24

MHA_AC::int_t Class Reference

Insert a integer variable into the AC space.

Public Attributes
• int data
Integer value variable.

4.24.1

Detailed Description

The variable is automatically removed on destruction.

4.25

MHA_AC::spectrum_t Class Reference

Insert a MHASignal::spectrum_t (p. 261) class into the AC space.
Inheritance diagram for MHA_AC::spectrum_t:

mha_spec_t

MHASignal::spectrum_t

MHA_AC::spectrum_t

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CONTENTS

Public Member Functions
• spectrum_t (algo_comm_t ac, std::string name, unsigned int bins, unsigned int channels, bool insert_now)
Create the AC variable.

• void insert ()
Insert AC variable into AC space.

Additional Inherited Members
4.25.1

Detailed Description

The variable is automatically removed on destruction.

4.25.2

Constructor & Destructor Documentation

4.25.2.1

MHA_AC::spectrum_t::spectrum_t ( algo_comm_t ac, std::string name, unsigned int bins,
unsigned int channels, bool insert_now )

Parameters
ac
name

AC handle
Name of variable in AC space

bins

Number of FFT bins in the waveform_t (p. 120) class

channels

Number of audio channels in the waveform_t (p. 120) class

insert_now

Insert implicitely in the constructor (true) or explicitely in the insert() (p. 120)
function (false)

4.26

MHA_AC::waveform_t Class Reference

Insert a MHASignal::waveform_t (p. 268) class into the AC space.
© 2005-2018 HörTech gGmbH, Oldenburg

4.26

MHA_AC::waveform_t Class Reference

121

Inheritance diagram for MHA_AC::waveform_t:

mha_wave_t

MHASignal::waveform_t

MHA_AC::waveform_t

Public Member Functions
• waveform_t (algo_comm_t ac, std::string name, unsigned int frames, unsigned int
channels, bool insert_now)
Create the AC variable.

• void insert ()
Insert AC variable into AC space.

Additional Inherited Members
4.26.1

Detailed Description

The variable is automatically removed on destruction.

4.26.2

Constructor & Destructor Documentation

4.26.2.1

MHA_AC::waveform_t::waveform_t ( algo_comm_t ac, std::string name, unsigned int
frames, unsigned int channels, bool insert_now )

Parameters
ac
name

AC handle
Name of variable in AC space

frames

Number of frames in the waveform_t (p. 120) class

channels

Number of audio channels in the waveform_t (p. 120) class

Insert implicitely in the constructor (true) or explicitely in the insert() (p. 121)
function
© 2005-2018 HörTech
gGmbH,(false)
Oldenburg
insert_now

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4.27

CONTENTS

mha_audio_descriptor_t Struct Reference

Description of an audio fragment (planned as a replacement of mhaconfig_t (p. 155)).

Public Attributes
• unsigned int n_samples
Number of samples.

• unsigned int n_channels
Number of audio channels.

• unsigned int n_freqs
Number of frequency bands.

• unsigned int is_complex
Flag about sample type.

• mha_real_t dt
Time distance between samples (only equidistant samples allowed)

• mha_real_t ∗ cf
Center frequencies of frequency bands.

• mha_real_t ∗ chdir
Hint on source direction of channel, values below zero is left, values above zero is right, zero
means unknown.

4.28

mha_audio_t Struct Reference

An audio fragment in the openMHA (planned as a replacement of mha_wave_t (p. 154) and
mha_spec_t (p. 141)).

Public Attributes
• mha_audio_descriptor_t descriptor
Dimension and description of the data.

• mha_real_t ∗ rdata
Data pointer if flag mha_audio_descriptor_t::is_complex ( p. 122) is unset.

• mha_complex_t ∗ cdata
Data pointer if flag mha_audio_descriptor_t::is_complex ( p. 122) is set.

4.28.1

Detailed Description

The data alignment is (t0 , c0 , f0 ), (t0 , c0 , f1 ), . . . , (t0 , c0 , ff reqs ), (t0 , c1 , f0 ), . . .. This allows a direct cast of the current mha_wave_t (p. 154) and mha_spec_t (p. 141) data pointers into corresponding mha_audio_t (p. 122) objects.
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4.29

4.28.2

mha_channel_info_t Struct Reference

Member Data Documentation

4.28.2.1 mha_audio_descriptor_t mha_audio_t::descriptor

4.28.2.2 mha_real_t∗ mha_audio_t::rdata

4.28.2.3 mha_complex_t∗ mha_audio_t::cdata

4.29

mha_channel_info_t Struct Reference

Channel information structure.

Public Attributes
• int id
channel id

• char idstr [32]
channel id

• unsigned int side
side (left/right)

• mha_direction_t dir
source direction

• mha_real_t peaklevel
Peak level corresponds to this SPL (dB) level.

4.30

mha_complex_t Struct Reference

Type for complex floating point values.

Public Attributes
• mha_real_t re
Real part.

• mha_real_t im
Imaginary part.
© 2005-2018 HörTech gGmbH, Oldenburg

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124

4.30.1

CONTENTS

Member Data Documentation

4.30.1.1 mha_real_t mha_complex_t::re
4.30.1.2 mha_real_t mha_complex_t::im

4.31

mha_dblbuf_t< FIFO > Class Template Reference

The doublebuffer adapts blocksizes between an outer process, which provides input data and
takes output data, and an inner process, which processes the input signal and generates output
data using a different block size than the outer process.

Public Types
• typedef FIFO::value_type value_type
The datatype exchanged by the FIFO and this doublebuffer.

Public Member Functions
• mha_dblbuf_t (unsigned outer_size, unsigned inner_size, unsigned delay, unsigned
input_channels, unsigned output_channels, const value_type &delay_data)
Constructor creates FIFOs with specified delay.

• virtual void process (const value_type ∗input_signal, value_type ∗output_signal, unsigned count)
The outer process has to call this method to propagate the input signal to the inner process,
and receives back the output signal.

• virtual void input (value_type ∗input_signal)
The inner process has to call this method to receive its input signal.

• virtual void output (const value_type ∗output_signal)
The outer process has to call this method to deliver its output signal.

Private Attributes
• unsigned outer_size
The block size used by the outer process.

• unsigned inner_size
The block size used by the inner process.

• unsigned delay
The delay introduced by bidirectional buffer size adaptation.

• unsigned fifo_size
The size of each of the FIFOs.

• unsigned input_channels
The number of input channels.
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mha_dblbuf_t< FIFO > Class Template Reference

125

• unsigned output_channels
The number of output channels.

• FIFO input_fifo
The FIFO for transporting the input signal from the outer process to the inner process.

• FIFO output_fifo
The FIFO for transporting the output signal from the inner process to the outer process.

• MHA_Error ∗ inner_error
Owned copy of exception to be thrown in inner thread.

• MHA_Error ∗ outer_error
Owned copy of exception to be thrown in outer thread.

4.31.1

Detailed Description

template
class mha_dblbuf_t< FIFO >
This class introduces the channels concept. Input and output may have different channel
counts.

4.31.2

Constructor & Destructor Documentation

4.31.2.1

template mha_dblbuf_t< FIFO >::mha_dblbuf_t ( unsigned outer_size,
unsigned inner_size, unsigned delay, unsigned input_channels, unsigned output_channels,
const value_type & delay_data )

Warning
The doublebuffer may block or raise an exception if the delay is too small. To avoid this,
the delay should be
delay >= (inner_size − gcd(inner_size, outer_size))
.
Parameters
outer_size
inner_size
delay

The block size used by the outer process.
The block size used by the inner process.
The total delay

input_channels

Number of input channels

output_channels

Number of output channels

delay_data

The delay consists of copies of this value.

© 2005-2018 HörTech gGmbH, Oldenburg

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4.31.3
4.31.3.1

CONTENTS

Member Function Documentation
template void mha_dblbuf_t< FIFO >::process ( const value_type ∗
input_signal, value_type ∗ output_signal, unsigned count ) [virtual]

Parameters
input_signal
output_signal

Pointer to the input signal array.
Pointer to the output signal array.

count

The number of data instances provided and expected, lower or equal to
inner_size given to constructor.

Exceptions
MHA_Error ( p. 132)

4.31.3.2

When count is > outer_size as given to constructor or the underlying
fifo implementation detects an error.

template void mha_dblbuf_t< FIFO >::input ( value_type ∗ input_signal )
[virtual]

Parameters
input_signal

Array where the doublebuffer can store the signal.

Exceptions
MHA_Error ( p. 132)

4.31.3.3

When the underlying fifo implementation detects an error.

template void mha_dblbuf_t< FIFO >::output ( const value_type ∗
output_signal ) [virtual]

Parameters
output_signal

Array from which doublebuffer reads outputsignal.

Exceptions
MHA_Error ( p. 132)

4.31.4
4.31.4.1

When the underlying fifo implementation detects an error.

Member Data Documentation
template unsigned mha_dblbuf_t< FIFO >::outer_size [private]

© 2005-2018 HörTech gGmbH, Oldenburg

4.32

mha_direction_t Struct Reference

127

4.31.4.2

template unsigned mha_dblbuf_t< FIFO >::inner_size [private]

4.31.4.3

template unsigned mha_dblbuf_t< FIFO >::delay [private]

4.31.4.4

template FIFO mha_dblbuf_t< FIFO >::input_fifo [private]

4.31.4.5

template FIFO mha_dblbuf_t< FIFO >::output_fifo [private]

4.32

mha_direction_t Struct Reference

Channel source direction structure.

Public Attributes
• mha_real_t azimuth
azimuth in radiants

• mha_real_t elevation
elevation in radiants

• mha_real_t distance
distance in meters

4.33

mha_drifter_fifo_t< T > Class Template Reference

A FIFO class for blocksize adaptation without Synchronization.
Inheritance diagram for mha_drifter_fifo_t< T >:

mha_fifo_t< T >

mha_drifter_fifo_t< T >

© 2005-2018 HörTech gGmbH, Oldenburg

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CONTENTS

Public Member Functions
• virtual void write (const T ∗data, unsigned count)
write data to fifo

• virtual void read (T ∗buf, unsigned count)
Read data from fifo.

• virtual unsigned get_fill_count () const
Return fill_count, adding mha_drifter_fifo_t::startup_zeros ( p. 131) to the number of
samples actually in the fifo's buffer.

• virtual unsigned get_available_space () const
Return available space, subtracting number of mha_drifter_fifo_t::startup_zeros
( p. 131) from the available_space actually present in the fifo's buffer.

• virtual unsigned get_des_fill_count () const
The desired fill count of this fifo.

• virtual unsigned get_min_fill_count () const
The minimum fill count of this fifo.

• virtual void stop ()
Called by mha_drifter_fifo_t::read ( p. 130) or mha_drifter_fifo_t::write ( p. 129)
when their xrun in succession counter exceeds its limit.

• virtual void starting ()
Called by mha_drifter_fifo_t::read ( p. 130) or mha_drifter_fifo_t::write ( p. 129)
when the respective flag (mha_drifter_fifo_t::reader_started ( p. 131) or mha_drifter←_fifo_t::writer_started ( p. 131)) is about to be toggled from false to true.

• mha_drifter_fifo_t (unsigned min_fill_count, unsigned desired_fill_count, unsigned
max_fill_count)
Create drifter FIFO.

• mha_drifter_fifo_t (unsigned min_fill_count, unsigned desired_fill_count, unsigned
max_fill_count, const T &t)
Create drifter FIFO where all (initially unused) copies of T are initialized as copies of t.

Private Attributes
• const unsigned minimum_fill_count
The minimum fill count of this fifo.

• const unsigned desired_fill_count
The desired fill count of the fifo.

• bool writer_started
Flag set to true when write is called the first time.

• bool reader_started
Flag set to true when read is called for the first time.

• unsigned writer_xruns_total
The number of xruns seen by the writer since object instantiation.

• unsigned reader_xruns_total
The number of xruns seen by the reader since object instantiation.

• unsigned writer_xruns_since_start
The number of xruns seen by the writer since the last start of processing.
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4.33

mha_drifter_fifo_t< T > Class Template Reference

129

• unsigned reader_xruns_since_start
The number of xruns seen by the reader since the last start of processing.

• unsigned writer_xruns_in_succession
The number of xruns seen by the writer in succession.

• unsigned reader_xruns_in_succession
The number of xruns seen by the reader in succession.

• unsigned maximum_writer_xruns_in_succession_before_stop
A limit to the number of xruns seen in succession during write before the data transmission
through the FIFO is stopped.

• unsigned maximum_reader_xruns_in_succession_before_stop
A limit to the number of xruns seen in succession during read before the data transmission
through the FIFO is stopped.

• mha_fifo_t< T >::value_type null_data
The value used in place of missing data.

• unsigned startup_zeros
When processing starts, that is when both mha_drifter_fifo_t::reader_started ( p. 131)
and mha_drifter_fifo_t::writer_started ( p. 131) are true, then first mha_drifter_fifo←_t::desired_fill_count ( p. 131) instances of mha_drifter_fifo_t::null_data ( p. 129)
are delivered to the reader.

Additional Inherited Members
4.33.1

Detailed Description

template
class mha_drifter_fifo_t< T >
Features: delay concept (desired, minimum and maximum delay), drifting support by throwing
away data or inserting zeroes.

4.33.2
4.33.2.1

4.33.3
4.33.3.1

Constructor & Destructor Documentation
template mha_drifter_fifo_t< T >::mha_drifter_fifo_t ( unsigned
min_fill_count, unsigned desired_fill_count, unsigned max_fill_count )
Member Function Documentation
template void mha_drifter_fifo_t< T >::write ( const T ∗ data, unsigned count )
[virtual]

Sets writer_started (p. 131) to true.
When processing has started, i.e. both reader_started (p. 131) and writer_started (p. 131)
are true, write specified ammount of data to the fifo. If there is not enough space available, then
the exceeding data is lost and the writer xrun counters are increased.
Processing is stopped when writer_xruns_in_succession (p. 131) exceeds maximum_←writer_xruns_in_succession_before_stop (p. 131).

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CONTENTS

Parameters
data
count

Pointer to source data.
Number of instances to copy

Reimplemented from mha_fifo_t< T > (p. 136).
4.33.3.2

template void mha_drifter_fifo_t< T >::read ( T ∗ buf, unsigned count )
[virtual]

Sets reader_started (p. 131) to true.
When processing has started, i.e. both reader_started (p. 131) and writer_started (p. 131)
are true, then read specified ammount of data from the fifo. As long as startup_zeros (p. 131)
is > 0, null_data (p. 129) is delivered to the reader and startup_zeros (p. 131) is diminished.
Only when startup_zeros (p. 131) has reached 0, data is actually read from the fifo's buffer.
If the read would cause the fifo's fill count to drop below minimum_fill_count (p. 131), then
only so much data are read that minimum_fill_count (p. 131) entries remain in the fifo, the
missing data is replaced with null_data (p. 129), and the reader xrun counters are increased.
Processing is stopped when reader_xruns_in_succession (p. 131) exceeds maximum_←reader_xruns_in_succession_before_stop (p. 131).
Parameters
buf

Pointer to the target buffer

count

Number of instances to copy

Reimplemented from mha_fifo_t< T > (p. 137).
4.33.3.3

template unsigned mha_drifter_fifo_t< T >::get_fill_count (
[virtual]

) const

Reimplemented from mha_fifo_t< T > (p. 135).
4.33.3.4

template unsigned mha_drifter_fifo_t< T >::get_available_space ( ) const
[virtual]

TODO: uncertain if this is a good idea.
Reimplemented from mha_fifo_t< T > (p. 135).
4.33.3.5

template void mha_drifter_fifo_t< T >::stop ( ) [virtual]

Called by read (p. 130) or write (p. 129) when their xrun in succession counter exceeds its limit.
May also be called explicitly.
© 2005-2018 HörTech gGmbH, Oldenburg

4.33

mha_drifter_fifo_t< T > Class Template Reference

4.33.3.6

131

template void mha_drifter_fifo_t< T >::starting ( ) [virtual]

The fifo's buffer is emptied, this method resets startup_zeros (p. 131) to desired_fill_count
(p. 131), and it also resets reader_xruns_since_start (p. 129) and writer_xruns_since_start
(p. 131) to 0.

4.33.4

Member Data Documentation

4.33.4.1

template const unsigned mha_drifter_fifo_t< T >::minimum_fill_count
[private]

4.33.4.2

template const unsigned mha_drifter_fifo_t< T >::desired_fill_count
[private]

The fifo is initialized with this ammount of data when data transmission starts.
4.33.4.3

template bool mha_drifter_fifo_t< T >::writer_started [private]

4.33.4.4

template bool mha_drifter_fifo_t< T >::reader_started [private]

4.33.4.5

template unsigned mha_drifter_fifo_t< T >::writer_xruns_since_start
[private]

4.33.4.6

template unsigned mha_drifter_fifo_t< T >::writer_xruns_in_succession
[private]

Reset to 0 every time a write succeeds without xrun.
4.33.4.7

template unsigned mha_drifter_fifo_t< T >::reader_xruns_in_succession
[private]

Reset to 0 every time a read succeeds without xrun.
4.33.4.8

template unsigned mha_drifter_fifo_t< T >::maximum_writer_xruns_in_←succession_before_stop [private]

4.33.4.9

template unsigned mha_drifter_fifo_t< T >::maximum_reader_xruns_in_←succession_before_stop [private]

4.33.4.10

template unsigned mha_drifter_fifo_t< T >::startup_zeros [private]

These null_data (p. 129) instances are not transmitted through the fifo because filling the fifo
with enough null_data (p. 129) might not be realtime safe and this filling has to be initiated by
starting (p. 131) or stop (p. 130) (this implementation: starting (p. 131)) which are be called
with realtime constraints.
© 2005-2018 HörTech gGmbH, Oldenburg

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4.34

CONTENTS

MHA_Error Class Reference

Error reporting exception class.
Inherits exception.

Public Member Functions
• MHA_Error (const char ∗file, int line, const char ∗fmt,...)
Create an instance of a MHA_Error ( p. 132).

• const char ∗ get_msg () const
Return the error message without source position.

• const char ∗ get_longmsg () const
Return the error message with source position.

• const char ∗ what () const throw ()
overwrite std::execption::what()

4.34.1

Detailed Description

This class is used for error handling in the openMHA. It is used by the openMHA kernel and by
the openMHA toolbox library. Please note that exceptions should not be used accross ANSI-C
interfaces. It is necessary to catch exceptions within the library.
The MHA_Error (p. 132) class holds source file name, line number and an error message.

4.34.2

Constructor & Destructor Documentation

4.34.2.1

MHA_Error::MHA_Error ( const char ∗ s_file, int l, const char ∗ fmt, ... )

Parameters
s_file

source file name (FILE)

l

source line (LINE)

fmt

format string for error message (as in printf)

4.35

mha_fifo_lw_t< T > Class Template Reference

This FIFO uses locks to synchronize access.
© 2005-2018 HörTech gGmbH, Oldenburg

4.35

mha_fifo_lw_t< T > Class Template Reference

133

Inheritance diagram for mha_fifo_lw_t< T >:

mha_fifo_t< T >

mha_fifo_lw_t< T >

Public Member Functions
• virtual void write (const T ∗data, unsigned count)
write specified ammount of data to the fifo.

• virtual void read (T ∗buf, unsigned count)
read data from fifo.

• mha_fifo_lw_t (unsigned max_fill_count)
Create FIFO with fixed buffer size.

• virtual ∼mha_fifo_lw_t ()
release synchronization object

• virtual void set_error (unsigned index, MHA_Error ∗error)
Process waiting for more data or space should bail out, throwing this error.

Private Attributes
• mha_fifo_thread_platform_t ∗ sync
platform specific thread synchronization

• MHA_Error ∗ error [2]
If waiting for synchronization should be aborted then exception to be thrown by reader process
(index 0) or writer process (index 1) has to be placed here.

Additional Inherited Members
4.35.1

Detailed Description

template
class mha_fifo_lw_t< T >
Reading and writing can block until the operation can be executed.
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4.35.2
4.35.2.1

CONTENTS

Member Function Documentation
template void mha_fifo_lw_t< T >::write ( const T ∗ data, unsigned count )
[virtual]

If there is not enough space, then wait for more space.
Parameters
data
count

Pointer to source data.
Number of instances to copy.

Exceptions
MHA_Error ( p. 132)

when detecting a deadlock situation.

Reimplemented from mha_fifo_t< T > (p. 136).
4.35.2.2

template void mha_fifo_lw_t< T >::read ( T ∗ buf, unsigned count )
[virtual]

If there is not enough data, then wait for more data.
Parameters
buf

Pointer to the target buffer.

count

Number of instances to copy.

Exceptions
MHA_Error ( p. 132)

when detecting a deadlock situation.

Reimplemented from mha_fifo_t< T > (p. 137).
4.35.2.3

template void mha_fifo_lw_t< T >::set_error ( unsigned index, MHA_Error ∗
error ) [virtual]

Parameters
index

Use 0 for terminating reader, 1 for terminating writer.

error

MHA_Error (p. 132) to be thrown

4.35.3

Member Data Documentation

© 2005-2018 HörTech gGmbH, Oldenburg

4.36

mha_fifo_t< T > Class Template Reference

4.35.3.1

4.36

135

template MHA_Error∗ mha_fifo_lw_t< T >::error[2] [private]

mha_fifo_t< T > Class Template Reference

A FIFO class for blocksize adaptation Synchronization: None.
Inheritance diagram for mha_fifo_t< T >:

mha_fifo_t< T >

mha_drifter_fifo_t< T >

mha_fifo_lw_t< T >

Public Types
• typedef T value_type
The data type exchanged by this fifo.

Public Member Functions
• virtual void write (const T ∗data, unsigned count)
write specified ammount of data to the fifo.

• virtual void read (T ∗buf, unsigned count)
read data from fifo

• virtual unsigned get_fill_count () const
Read-only access to fill_count.

• virtual unsigned get_available_space () const
Read-only access to available_space.

• virtual unsigned get_max_fill_count () const
The capacity of this fifo.

• mha_fifo_t (unsigned max_fill_count)
Create FIFO with fixed buffer size.

• mha_fifo_t (unsigned max_fill_count, const T &t)
Create FIFO with fixed buffer size, where all (initially unused) copies of T are initialized as
copies of t.

• mha_fifo_t (const mha_fifo_t &src)
Copy constructor.

• virtual ∼mha_fifo_t ()
Destroy FIFO.

• mha_fifo_t< T > & operator= (const mha_fifo_t< T > &)
Assignment operator.
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CONTENTS

Protected Member Functions
• void clear ()
Empty the fifo at once.

Private Attributes
• const unsigned max_fill_count
The maximum fill count of this FIFO.

• T ∗ buf
The memory allocated to store the data.

• T ∗ write_ptr
points to location where to write next

• const T ∗ read_ptr
points to location where to read next

• bool buf_uses_placement_new
wether buf was allocated using placement new or array new.

4.36.1

Detailed Description

template
class mha_fifo_t< T >
Use external synchronisation or synchronization in inheriting class.

4.36.2
4.36.2.1

Member Function Documentation
template void mha_fifo_t< T >::write ( const T ∗ data, unsigned count )
[virtual]

Parameters
data
count

Pointer to source data.
Number of instances to copy

Exceptions
MHA_Error ( p. 132)

when there is not enough space available.

Reimplemented in mha_fifo_lw_t< T > (p. 134), and mha_drifter_fifo_t< T > (p. 129).
© 2005-2018 HörTech gGmbH, Oldenburg

4.37

mha_fifo_thread_guard_t Class Reference

4.36.2.2

137

template void mha_fifo_t< T >::read ( T ∗ buf, unsigned count ) [virtual]

Parameters
buf

Pointer to the target buffer

count

Number of instances to copy

Exceptions
MHA_Error ( p. 132)

when there is not enough data available.

Reimplemented in mha_fifo_lw_t< T > (p. 134), and mha_drifter_fifo_t< T > (p. 130).
4.36.2.3

template void mha_fifo_t< T >::clear ( ) [inline], [protected]

Should be called by the reader, or when the reader is inactive.

4.36.3

Member Data Documentation

4.36.3.1

template const unsigned mha_fifo_t< T >::max_fill_count [private]

4.36.3.2

template T∗ mha_fifo_t< T >::buf [private]

max_fill_count + 1 locations are allocated: At least one location is always unused, because we
have max_fill_count + 1 possible fillcounts [0:max_fill_count] that we need to distinguish.
4.36.3.3

4.37

template bool mha_fifo_t< T >::buf_uses_placement_new [private]

mha_fifo_thread_guard_t Class Reference

Simple Mutex Guard Class.

4.38

mha_fifo_thread_platform_t Class Reference

Abstract base class for synchronizing multithreaded (producer/consumer) fifo operations.
Inherited by mha_fifo_posix_threads_t.
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CONTENTS

Public Member Functions
• virtual void aquire_mutex ()=0
Calling thread waits until it aquires the lock.

• virtual void release_mutex ()=0
Calling thread releases the lock.

• virtual void wait_for_decrease ()=0
Calling producer thread must own the lock.

• virtual void wait_for_increase ()=0
Calling consumer thread must own the lock.

• virtual void increment ()=0
To be called by producer thread after producing.

• virtual void decrement ()=0
To be called by consumer thread after consuming.

• virtual ∼mha_fifo_thread_platform_t ()
Make destructor virtual.

• mha_fifo_thread_platform_t ()
Make default constructor accessible.

4.38.1

Detailed Description

Works only with single producer and single consumer.

4.38.2
4.38.2.1

Member Function Documentation
virtual void mha_fifo_thread_platform_t::aquire_mutex ( ) [pure virtual]

Must not be called when the lock is already aquired.
4.38.2.2

virtual void mha_fifo_thread_platform_t::release_mutex ( ) [pure virtual]

May only be called when lock is owned.
4.38.2.3

virtual void mha_fifo_thread_platform_t::wait_for_decrease ( ) [pure virtual]

Method releases lock, and waits for consumer thread to call decrease(). Then reaquires lock
and returns
4.38.2.4

virtual void mha_fifo_thread_platform_t::wait_for_increase ( ) [pure virtual]

Method releases lock, and waits for producer thread to call increase(). Then reaquires lock and
returns
© 2005-2018 HörTech gGmbH, Oldenburg

4.39

mha_rt_fifo_element_t< T > Class Template Reference

4.38.2.5

139

virtual void mha_fifo_thread_platform_t::increment ( ) [pure virtual]

Producer thread needs to own the lock to call this method.
4.38.2.6

virtual void mha_fifo_thread_platform_t::decrement ( ) [pure virtual]

Consumer thread needs to own the lock to call this method.

4.39

mha_rt_fifo_element_t< T > Class Template Reference

Object wrapper for mha_rt_fifo_t (p. 140).

Public Member Functions
• mha_rt_fifo_element_t (T ∗data)
Constructor.

Public Attributes
• mha_rt_fifo_element_t< T > ∗ next
Pointer to next fifo element. NULL for the last (newest) fifo element.

• bool abandonned
Indicates that this element will no longer be used and may be deleted.

• T ∗ data
Pointer to user data.

4.39.1
4.39.1.1

Constructor & Destructor Documentation
template mha_rt_fifo_element_t< T >::mha_rt_fifo_element_t ( T ∗ data )
[inline]

This element assumes ownership of user data.
Parameters
data

User data. Has to be allocated on the heap with standard operator new, because it
will be deleted in this element's destructor.

© 2005-2018 HörTech gGmbH, Oldenburg

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4.40

CONTENTS

mha_rt_fifo_t< T > Class Template Reference

Template class for thread safe, half real time safe fifo without explixit locks.

Public Member Functions
• mha_rt_fifo_t ()
Construct empty fifo.

• ∼mha_rt_fifo_t ()
Destructor will delete all data currently in the fifo.

• T ∗ poll ()
Retrieve the latest element in the Fifo.

• T ∗ poll_1 ()
Retrieve the next element in the Fifo, if there is one, and mark the previous element as abandonned.

• void push (T ∗data)
Add element to the Fifo.

Private Member Functions
• void remove_abandonned ()
Deletes abandonned elements.

• void remove_all ()
Deletes all elements.

Private Attributes
• mha_rt_fifo_element_t< T > ∗ root
The first element in the fifo. Deleting elements starts here.

• mha_rt_fifo_element_t< T > ∗ current
The element most recently returned by poll ( p. 141) or poll_1 ( p. 141).

4.40.1

Detailed Description

template
class mha_rt_fifo_t< T >
Reading from this fifo is realtime safe, writing to it is not. This fifo is designed for objects that
were constructed on the heap. It assumes ownership of these objects and calls delete on them
when they are no longer used. Objects remain inside the Fifo while being used by the reader.
A new fifo element is inserted by using push (p. 141). The push operation is not real time safe,
it allocates and deallocates memory. The latest element is retrieved by calling poll (p. 141).
This operation will skip fifo elements if more than one push (p. 141) has been occured since
the last poll. To avoid skipping, call the poll_1 (p. 141) operation instead.
© 2005-2018 HörTech gGmbH, Oldenburg

4.41

mha_spec_t Struct Reference

4.40.2

Member Function Documentation

4.40.2.1

141

template T∗ mha_rt_fifo_t< T >::poll ( ) [inline]

Will skip fifo elements if more than one element has been added since last poll invocation. Will
return the same element as on last call if no elements have been added in the mean time.
Marks former elements as abandonned.
Returns
The latest element in this Fifo. Returns NULL if the Fifo is empty.

4.40.2.2

template T∗ mha_rt_fifo_t< T >::poll_1 ( ) [inline]

Else, if there is no newer element, returns the same element as on last poll() (p. 141) or poll_1()
(p. 141) invocation.
Returns
The next element in this Fifo, if there is one, or the same as before. Returns NULL if the
Fifo is empty.

4.40.2.3

template void mha_rt_fifo_t< T >::push ( T ∗ data ) [inline]

Deletes abandonned elements in the fifo.
Parameters
The new user data to place at the end of the fifo. After this invocation, the fifo is the
owner of this object and will delete it when it is no longer used. data must have been
allocated on the heap with standard operator new.

data

4.40.3

Member Data Documentation

4.40.3.1

template mha_rt_fifo_element_t∗ mha_rt_fifo_t< T >::current
[private]

Searching for new elements starts here.

4.41

mha_spec_t Struct Reference

Spectrum signal structure.
© 2005-2018 HörTech gGmbH, Oldenburg

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CONTENTS

Inheritance diagram for mha_spec_t:

mha_spec_t

MHASignal::spectrum_t

MHA_AC::spectrum_t

Public Attributes
• mha_complex_t ∗ buf
signal buffer

• unsigned int num_channels
number of channels

• unsigned int num_frames
number of frames in each channel

• mha_channel_info_t ∗ channel_info
detailed channel description

4.41.1

Detailed Description

This structure contains the short time fourier transform output of the windowed input signal.
The member num_frames describes the number of frequency bins in each channel. For an
even FFT length N , this is N/2 + 1. With odd FFT lengths, it is (N + 1)/2. The imaginary part
of the first bin is zero. For even FFT lengths, also the imaginary part at the Nyquist frequency
is zero.
buf[k].re

Re(0)

buf[k].im
k

0

Re(1) Re(2) Re(3) Re(4)

...

Re(n/2−1)

Im(1) Im(2) Im(3) Im(4)

...

Im(n/2−1)

1

2

3

4

n/2−1

Re(n/2)

n/2

Figure 4 Data order of FFT spectrum.

© 2005-2018 HörTech gGmbH, Oldenburg

4.42

MHA_TCP::Async_Notify Class Reference

4.42

MHA_TCP::Async_Notify Class Reference

143

Portable Multiplexable cross-thread notification.
Inheritance diagram for MHA_TCP::Async_Notify:

MHA_TCP::Wakeup_Event

MHA_TCP::Async_Notify

Additional Inherited Members

4.43

MHA_TCP::Client Class Reference

A portable class for a tcp client connections.
Inheritance diagram for MHA_TCP::Client:

MHA_TCP::Connection

MHA_TCP::Client

Public Member Functions
• Client (const std::string &host, unsigned short port)
Constructor connects to host, port via TCP.

• Client (const std::string &host, unsigned short port, Timeout_Watcher &timeout_←watcher)
Constructor connects to host, port via TCP, using a timeout.
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CONTENTS

Additional Inherited Members
4.43.1

Constructor & Destructor Documentation

4.43.1.1

Client::Client ( const std::string & host, unsigned short port )

Parameters
The hostname of the TCP Server.
The port or the TCP Server.

host
port

4.43.1.2

Client::Client ( const std::string & host, unsigned short port, Timeout_Watcher &
timeout_watcher )

Parameters
host
port
timeout_watcher

4.44

The hostname of the TCP Server.
The port or the TCP Server.
an Event watcher that implements a timeout.

MHA_TCP::Connection Class Reference

Connection (p. 144) handles Communication between client and server, is used on both sides.
Inheritance diagram for MHA_TCP::Connection:

MHA_TCP::Connection

MHA_TCP::Client

Public Member Functions
• std::string get_peer_address ()
Get peer's IP Address.

• unsigned short get_peer_port ()
© 2005-2018 HörTech gGmbH, Oldenburg

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MHA_TCP::Connection Class Reference

145

Get peer's TCP port.

• SOCKET get_fd () const
Return the (protected) file descriptor of the connection.

• virtual ∼Connection ()
Destructor closes the underlying file descriptor.

• bool eof ()
Checks if the peer has closed the connection.

• bool can_read_line (char delim= '\n')
Checks if a full line of text has arrived by now.

• bool can_read_bytes (unsigned howmany)
Checks if the specified ammount of data can be read.

• std::string read_line (char delim= '\n')
Reads a single line of data from the socket.

• std::string read_bytes (unsigned howmany)
Reads the specified ammount of dat from the socket.

• void try_write (const std::string &data="")
Adds data to the internal "outgoing" buffer, and then tries to write as much data from that buffer
to the socket as possible without blocking.

• void write (const std::string &data="")
Adds data to the internal "outgoing" buffer, and then writes that that buffer to the socket, regardless of blocking.

• bool needs_write ()
Checks if the internal "outgoing" buffer contains data.

• unsigned buffered_incoming_bytes () const
Returns the number of bytes in the internal "incoming" buffer.

• unsigned buffered_outgoing_bytes () const
Returns the number of bytes in the internal "outgoing" buffer.

Protected Member Functions
• Connection (SOCKET _fd)
Create a connection instance from a socket filedescriptor.

Protected Attributes
• SOCKET fd
The file descriptor of the TCP Socket.
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CONTENTS

Private Member Functions
• void init_peer_data ()
determine peer address and port

• bool can_sysread ()
Determine wether at least 1 byte can be read without blocking.

• bool can_syswrite ()
Determine wether at least 1 byte can be written without blocking.

• std::string sysread (unsigned bytes)
Call the system's read function and try to read bytes.

• std::string syswrite (const std::string &data)
Call the system's write function and try to write all characters in the string data.

4.44.1

Constructor & Destructor Documentation

4.44.1.1

MHA_TCP::Connection::Connection ( SOCKET _fd ) [protected]

Parameters
The file descriptor of the TCP Socket. This file descriptor is closed again in the
destructor.

←-

_←fd

Exceptions
MHA_Error ( p. 132)

4.44.2

If the file descriptor is < 0.

Member Function Documentation

4.44.2.1

std::string Connection::sysread ( unsigned bytes ) [private]

This will block in a situation where can_sysread returns false.
Parameters
bytes

The desired number of characters.

Returns
The characters read from the socket. The result may have fewer characters than specified
by bytes. If the result is an empty string, then the socket has been closed by the peer.

© 2005-2018 HörTech gGmbH, Oldenburg

4.44

MHA_TCP::Connection Class Reference

4.44.2.2

147

std::string Connection::syswrite ( const std::string & data ) [private]

May write fewer characters, but will at least write one character.
Parameters
data

A string of characters to write to the socket.

Returns
The rest of the characters that have not yet been written.

4.44.2.3

SOCKET MHA_TCP::Connection::get_fd ( ) const [inline]

Will be required for SSL.
4.44.2.4

bool Connection::eof ( )

As a side effect, this method fills the internal "incoming" buffer if it was empty and the socket is
readable and not eof.
4.44.2.5

bool Connection::can_read_line ( char delim = '\n' )

This method reads data from the socket into the internal "incoming" buffer if it can be done
without blocking.
Parameters
delim

The line delimiter.

Returns
true if at least one full line of text is present in the internal buffer after this method call,
false otherwise.

4.44.2.6

bool Connection::can_read_bytes ( unsigned howmany )

This method reads data from the socket into an internal "incoming" buffer if it can be done
without blocking.
Parameters
howmany

The number of bytes that the caller wants to have checked.

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CONTENTS

Returns
true if at least the specified ammount of data is present in the internal buffer after this
method call, false otherwise

4.44.2.7

std::string Connection::read_line ( char delim = '\n' )

Blocks if necessary.
Parameters
delim

The line delimiter.

Returns
The string of characters in this line, including the trailing delimiter. The delimiter may be
missing if the last line before EOF does not have a delimiter.

4.44.2.8

std::string Connection::read_bytes ( unsigned howmany )

Blocks if necessary.
Parameters
howmany

The number of bytes to read.

Returns
The string of characters read. The string may be shorter if EOF is encountered.

4.44.2.9

void Connection::try_write ( const std::string & data = "" )

Parameters
data

4.44.2.10

data to send over the socket.

void Connection::write ( const std::string & data = "" )

Parameters
data

data to send over the socket.

© 2005-2018 HörTech gGmbH, Oldenburg

4.45

MHA_TCP::Event_Watcher Class Reference

4.45

MHA_TCP::Event_Watcher Class Reference

149

OS-independent event watcher, uses select on Unix and WaitForMultipleObjects on Windows.
Inheritance diagram for MHA_TCP::Event_Watcher:

MHA_TCP::Event_Watcher

MHA_TCP::Timeout_Watcher

Public Member Functions
• void observe (Wakeup_Event ∗event)
Add an event to this observer.

• void ignore (Wakeup_Event ∗event)
Remove an event from this observer.

• std::set< Wakeup_Event ∗ > wait ()
\ Wait for some event to occur.

Private Attributes
• std::set< Wakeup_Event ∗ > events
The list of events to watch.

4.45.1

4.45.1.1

Member Function Documentation

void Event_Watcher::observe ( Wakeup_Event ∗ event )

4.45.1.2 std::set< Wakeup_Event ∗ > Event_Watcher::wait ( )
Return all events that are ready
© 2005-2018 HörTech gGmbH, Oldenburg

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4.45.2

CONTENTS

Member Data Documentation

4.45.2.1 std::set MHA_TCP::Event_Watcher::events [private]

4.46

MHA_TCP::Sockread_Event Class Reference

Watch socket for incoming data.
Inheritance diagram for MHA_TCP::Sockread_Event:

MHA_TCP::Wakeup_Event

MHA_TCP::Sockread_Event

Public Member Functions
• Sockread_Event (SOCKET s)
Set socket to watch for.

4.46.1

Constructor & Destructor Documentation

4.46.1.1

MHA_TCP::Sockread_Event::Sockread_Event ( SOCKET s )

Parameters
The socket to observe incoming data on.

s

4.47

MHA_TCP::Thread Class Reference

A very simple class for portable threads.

Public Types
• typedef void ∗(∗ thr_f) (void ∗)
The thread function signature to use with this class.
© 2005-2018 HörTech gGmbH, Oldenburg

4.47

MHA_TCP::Thread Class Reference

151

Public Member Functions
• Thread (thr_f func, void ∗arg=0)
Constructor starts a new thread.

• virtual ∼Thread ()
The destructor should only be called when the Thread ( p. 150) is finished.

• virtual void run ()
The internal method that delegated the new thread to the registered Thread ( p. 150) function.

Public Attributes
• Async_Notify thread_finish_event
Event will be triggered when the thread exits.

• enum MHA_TCP::Thread:: { ... } state
The current state of the thread.

• thr_f thread_func
The thread function that the client has registered.

• void ∗ thread_arg
The argument that the client wants to be handed through to the thread function.

• MHA_Error ∗ error
The MHA_Error ( p. 132) that caused the thread to abort, if any.

Protected Member Functions
• Thread ()
Default constructor may only be used by derived classes that want to start the thread themselves.

Protected Attributes
• void ∗ arg
The argument for the client's thread function.

• void ∗ return_value
The return value from the client's thread function is stored here When that function returns.

Private Attributes
• pthread_t thread_handle
The posix thread handle.

• pthread_attr_t thread_attr
The posix thread attribute structure.
© 2005-2018 HörTech gGmbH, Oldenburg

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4.47.1

CONTENTS

Member Typedef Documentation

4.47.1.1

typedef void∗(∗ MHA_TCP::Thread::thr_f) (void ∗)

Derive from this class and call protected standard constructor to start threads differently.

4.47.2

Constructor & Destructor Documentation

4.47.2.1

Thread::Thread ( Thread::thr_f func, void ∗ arg = 0 )

Parameters
func

The function to be executed by the thread.

arg

The argument given to pass to the thread function.

4.47.2.2

Thread::∼Thread ( ) [virtual]

There is preliminary support for forceful thread cancellation in the destructor, but probably not
very robust or portable..

4.47.3

Member Data Documentation

4.47.3.1

pthread_attr_t MHA_TCP::Thread::thread_attr [private]

Required for starting a thread in detached state. Detachment is required to eliminate the need
for joining this thread.

4.47.3.2

void∗ MHA_TCP::Thread::arg [protected]

4.47.3.3

void∗ MHA_TCP::Thread::thread_arg

4.48

MHA_TCP::Timeout_Watcher Class Reference

OS-independent event watcher with internal fixed-end-time timeout.
© 2005-2018 HörTech gGmbH, Oldenburg

4.49

MHA_TCP::Wakeup_Event Class Reference

153

Inheritance diagram for MHA_TCP::Timeout_Watcher:

MHA_TCP::Event_Watcher

MHA_TCP::Timeout_Watcher

Additional Inherited Members

4.49

MHA_TCP::Wakeup_Event Class Reference

A base class for asynchronous wakeup events.
Inheritance diagram for MHA_TCP::Wakeup_Event:

MHA_TCP::Wakeup_Event

MHA_TCP::Async_Notify

MHA_TCP::Sockread_Event

Public Member Functions
• Wakeup_Event ()
Event Constructor.

• virtual void observed_by (Event_Watcher ∗observer)
Called by the Event_Watcher ( p. 149) when this event is added to its list of observed events.

• virtual void ignored_by (Event_Watcher ∗observer)
Called by the Event_Watcher ( p. 149) when this event is removed from its list of observed
events.

• virtual ∼Wakeup_Event ()
Destructor deregisters from observers.
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CONTENTS

• virtual OS_EVENT_TYPE get_os_event ()
Get necessary information for the Event Watcher.

• virtual void reset ()
For pure notification events, reset the "signalled" status.

• virtual bool status ()
Query wether the event is in signalled state now.

Private Attributes
• std::set< class Event_Watcher ∗ > observers
A list of all Event_Watcher ( p. 149) instances that this Wakeup_Event ( p. 153) is observed by
(stored here for proper deregistering).

4.49.1

Constructor & Destructor Documentation

4.49.1.1

Wakeup_Event::Wakeup_Event ( )

The new event has invalid state.

4.50

mha_wave_t Struct Reference

Waveform signal structure.
Inheritance diagram for mha_wave_t:

MHA_AC::waveform_t
MHAFilter::o1flt_maxtrack_t
MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAOvlFilter::fftfb_t

MHAOvlFilter::overlap
_save_filterbank_t

MHAFilter::o1flt_mintrack_t

MHASignal::async_rmslevel_t
mha_wave_t

MHASignal::waveform_t
MHASignal::loop_wavefragment_t
MHAWindow::bartlett_t
MHASignal::ringbuffer_t
MHAWindow::blackman_t
MHASignal::schroeder_t
MHAWindow::fun_t

MHAWindow::hamming_t

MHAWindow::user_t

MHAWindow::hanning_t

MHAWindow::base_t

MHAWindow::rect_t

© 2005-2018 HörTech gGmbH, Oldenburg

4.51

mhaconfig_t Struct Reference

155

Public Attributes
• mha_real_t ∗ buf
signal buffer

• unsigned int num_channels
number of channels

• unsigned int num_frames
number of frames in each channel

• mha_channel_info_t ∗ channel_info
detailed channel description

4.50.1

Detailed Description

This structure contains one fragment of a waveform signal. The member num_frames describes
the number of audio samples in each audio channel.
The field channel_info must be an array of num_channels entries or NULL.

4.51

mhaconfig_t Struct Reference

MHA prepare configuration structure.

Public Attributes
• unsigned int channels
Number of audio channels.

• unsigned int domain
Signal domain (MHA_WAVEFORM or MHA_SPECTRUM)

• unsigned int fragsize
Fragment size of waveform data.

• unsigned int wndlen
Window length of spectral data.

• unsigned int fftlen
FFT length of spectral data.

• mha_real_t srate
Sampling rate in Hz.

4.51.1

Detailed Description

This structure contains information about channel number and domain for input and output
signals of a openMHA Plugin. Each plugin can change any of these parameters, e.g. by
resampling of the signal. The only limitation is that the callback frequency is fixed (except for
the plugins db and dbasync).
© 2005-2018 HörTech gGmbH, Oldenburg

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4.52

CONTENTS

MHAEvents::emitter_t Class Reference

Class for emitting openMHA events.
Public Member Functions
• void operator() ()
Emit an event without parameter.

• void operator() (const std::string &)
Emit an event with string parameter.

• void operator() (const std::string &, unsigned int, unsigned int)
Emit an event with string parameter and two unsigned int parameters.

4.52.1

Detailed Description

Use the template claas MHAEvents::patchbay_t (p. 156) for connecting to an emitter.

4.53

MHAEvents::patchbay_t< receiver_t > Class Template Reference

Patchbay which connects any event emitter with any member function of the parameter class.
Public Member Functions
• void connect (emitter_t ∗, receiver_t ∗, void(receiver_t::∗)())
Connect a receiver member function void (receiver_t::∗)() with an event emitter.

• void connect (emitter_t ∗, receiver_t ∗, void(receiver_t::∗)(const std::string &))
Connect a receiver member function void (receiver_t::∗)(const std::string&) with an event emitter.

4.53.1

Detailed Description

template
class MHAEvents::patchbay_t< receiver_t >
The connections created by the connect() (p. 156) function are hold until the destructor is
called. To avoid access to invalid function pointers, it is required to destruct the patchbay
before the receiver, usually by declaring the patchbay as a member of the receiver.
The receiver can be any claas or structure; the event callback can be either a member function
without arguments or with const std::string& argument.
4.53.2
4.53.2.1

Member Function Documentation
template void MHAEvents::patchbay_t< receiver_t >::connect (
emitter_t ∗ e, receiver_t ∗ r, void(receiver_t::∗)() rfun )

Create a connection.
The connection is removed when the patchbay is destructed.

© 2005-2018 HörTech gGmbH, Oldenburg

4.54

MHAFilter::adapt_filter_t Class Reference

157

Parameters
Pointer to an event emitter
Pointer to the receiver
Pointer to a member function of the receiver class

e
r
rfun

4.53.2.2

template void MHAEvents::patchbay_t< receiver_t >::connect (
emitter_t ∗ e, receiver_t ∗ r, void(receiver_t::∗)(const std::string &) rfun )

Create a connection.
The connection is removed when the patchbay is destructed.
Parameters
e
r
rfun

4.54

Pointer to an event emitter
Pointer to the receiver
Pointer to a member function of the receiver class

MHAFilter::adapt_filter_t Class Reference

Adaptive filter.
Inheritance diagram for MHAFilter::adapt_filter_t:

MHAParser::base_t

MHAParser::parser_t

MHAPlugin::config_t
< adapt_filter_state_t >

MHAFilter::adapt_filter_t

MHAPlugin::config_t
< adapt_filter_param_t >

Additional Inherited Members

4.55

MHAFilter::blockprocessing_polyphase_resampling_t Class Reference

A class that does polyphase resampling and takes into account block processing.
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CONTENTS

Public Member Functions
• blockprocessing_polyphase_resampling_t (float source_srate, unsigned source_←fragsize, float target_srate, unsigned target_fragsize, float nyquist_ratio, float irslen, unsigned nchannels, bool add_delay)
Contructs a polyphase resampling filter that can be used for blockprocessing with the given
parameters.

• void write (mha_wave_t &signal)
Write signal to the ringbuffer.

• void read (mha_wave_t &signal)
Read resampled signal.

• bool can_read () const
Checks if the resampling ring buffer can produce another output signal block.

4.55.1

Detailed Description

4.55.2

Constructor & Destructor Documentation

4.55.2.1

MHAFilter::blockprocessing_polyphase_resampling_t::blockprocessing_polyphase_←resampling_t ( float source_srate, unsigned source_fragsize, float target_srate, unsigned
target_fragsize, float nyquist_ratio, float irslen, unsigned nchannels, bool add_delay )

Parameters
source_srate

Source sampling rate / Hz

source_fragsize

Fragment size of incoming audio blocks / frames at source_srate

target_srate

Target sampling rate / Hz

target_fragsize

Fragment size of produced audio blocks / frames at target_srate

nyquist_ratio

Low pass filter cutoff frequency relative to the nyquist frequency of the
smaller of the two sampling rates. Example values: 0.8, 0.9

irslen

Impulse response length used for low pass filtering / s

nchannels
add_delay

Number of audio channels
To avoid underruns, a delay is generally necessary for round trip block
size adaptations. It is only necessary to add this delay to one of the two
resampling chains. Set this parameter to true for the first resampling
object of a round trip pair. It will add the necessary delay, and calculate
the size of the ring buffer appropriately, When set to false, only the
ringbuffer size will be set sufficiently.

4.55.3
4.55.3.1

Member Function Documentation
void MHAFilter::blockprocessing_polyphase_resampling_t::write ( mha_wave_t & signal )

© 2005-2018 HörTech gGmbH, Oldenburg

4.56

MHAFilter::complex_bandpass_t Class Reference

159

Parameters
signal

input signal in original sampling rate

Exceptions
MHA_Error ( p. 132)

4.55.3.2

Raises exception if there is not enough room, if the number of
channels does not match, or if the number of frames is not equal to
the number specified in the constructor

void MHAFilter::blockprocessing_polyphase_resampling_t::read ( mha_wave_t & signal )

Will perform the resampling and remove no longer needed samples from the input buffer.
Parameters
signal

buffer to write the resampled signal to.

Exceptions
MHA_Error ( p. 132)

4.56

Raises exception if there is not enough input signal, if the number of
channels of frames does not match.

MHAFilter::complex_bandpass_t Class Reference

Complex bandpass filter.

Public Member Functions
• complex_bandpass_t (std::vector< mha_complex_t > A, std::vector< mha_←complex_t > B)
Constructor with filter coefficients (one per channel)

• void set_weights (std::vector< mha_complex_t > new_B)
Allow to modify the input weights at a later stage.

• void filter (const mha_wave_t &X, mha_spec_t &Y)
Filter method for real value input.

• void filter (const mha_wave_t &X, mha_wave_t &Yre, mha_wave_t &Yim)
Filter method for real value input.

• void filter (const mha_spec_t &X, mha_spec_t &Y)
Filter method for complex value input.

• void filter (const mha_wave_t &Xre, const mha_wave_t &Xim, mha_wave_t &Yre,
mha_wave_t &Yim)
Filter method for complex value input.
© 2005-2018 HörTech gGmbH, Oldenburg

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4.56.1

CONTENTS

Constructor & Destructor Documentation

4.56.1.1

MHAFilter::complex_bandpass_t::complex_bandpass_t ( std::vector< mha_complex_t > A,
std::vector< mha_complex_t > B )

Parameters
A
B

4.57

complex filter coefficients, one per band
complex weights

MHAFilter::diff_t Class Reference

Differentiator class (non-normalized)
Inheritance diagram for MHAFilter::diff_t:

MHAFilter::filter_t

MHAFilter::diff_t

Additional Inherited Members

4.58

MHAFilter::fftfilter_t Class Reference

FFT based FIR filter implementation.
Inheritance diagram for MHAFilter::fftfilter_t:

MHAFilter::fftfilter_t

MHAFilter::resampling
_filter_t

© 2005-2018 HörTech gGmbH, Oldenburg

4.58

MHAFilter::fftfilter_t Class Reference

161

Public Member Functions
• fftfilter_t (unsigned int fragsize, unsigned int channels, unsigned int fftlen)
Constructor.

• void update_coeffs (const mha_wave_t ∗pwIRS)
Update the set of coefficients.

• void filter (const mha_wave_t ∗pwIn, mha_wave_t ∗∗ppwOut, const mha_wave_t ∗pw←IRS)
Apply filter with changing coefficients to a waveform fragment.

• void filter (const mha_wave_t ∗pwIn, mha_wave_t ∗∗ppwOut)
Apply filter to waveform fragment, without changing the coefficients.

• void filter (const mha_wave_t ∗pwIn, mha_wave_t ∗∗ppwOut, const mha_spec_t ∗ps←Weights)
Apply filter with changing coefficients to a waveform fragment.

4.58.1

Detailed Description

The maximal number of coefficients can be FFT length - fragsize + 1.

4.58.2

Constructor & Destructor Documentation

4.58.2.1

MHAFilter::fftfilter_t::fftfilter_t ( unsigned int fragsize, unsigned int channels, unsigned int
fftlen )

Parameters
fragsize

Number of frames expected in input signal (each cycle).

channels

Number of channels expected in input signal.

fftlen

FFT length of filter.

4.58.3

Member Function Documentation

4.58.3.1

void MHAFilter::fftfilter_t::update_coeffs ( const mha_wave_t ∗ pwIRS )

Parameters
pwIRS

Coefficients structure

Note
The number of channels in h must match the number of channels given in the constructor.
The filter length is limited to fftlen-fragsize+1 (longer IRS will be shortened).

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4.58.3.2

CONTENTS

void MHAFilter::fftfilter_t::filter ( const mha_wave_t ∗ pwIn, mha_wave_t ∗∗ ppwOut,
const mha_wave_t ∗ pwIRS )

Parameters
pw←In

Input signal pointer.

Return values
ppwOut

Pointer to output signal pointer, will be set to a valid signal.

Parameters
Pointer to FIR coefficients structure.

pwIRS

4.58.3.3

void MHAFilter::fftfilter_t::filter ( const mha_wave_t ∗ pwIn, mha_wave_t ∗∗ ppwOut )

Parameters
pw←In

Input signal pointer.

Return values
ppwOut

4.58.3.4

Pointer to output signal pointer, will be set to a valid signal

void MHAFilter::fftfilter_t::filter ( const mha_wave_t ∗ pwIn, mha_wave_t ∗∗ ppwOut,
const mha_spec_t ∗ psWeights )

Parameters
pw←In

Input signal pointer.

Return values
ppwOut

Pointer to output signal pointer, will be set to a valid signal.

Parameters
psWeights

Pointer to filter weights structure.

© 2005-2018 HörTech gGmbH, Oldenburg

4.59

MHAFilter::fftfilterbank_t Class Reference

4.59

MHAFilter::fftfilterbank_t Class Reference

163

FFT based FIR filterbank implementation.
Inheritance diagram for MHAFilter::fftfilterbank_t:

MHAFilter::fftfilterbank_t

MHAOvlFilter::overlap
_save_filterbank_t

Public Member Functions
• fftfilterbank_t (unsigned int fragsize, unsigned int inputchannels, unsigned int firchannels, unsigned int fftlen)
Constructor.

• void update_coeffs (const mha_wave_t ∗h)
Update the set of coefficients.

• void filter (const mha_wave_t ∗s_in, mha_wave_t ∗∗s_out, const mha_wave_t ∗h)
Apply filter with changing coefficients to a waveform fragment.

• void filter (const mha_wave_t ∗s_in, mha_wave_t ∗∗s_out)
Apply filter to waveform fragment, without changing the coefficients.

• const mha_wave_t ∗ get_irs () const
Return the current IRS.

4.59.1

Detailed Description

This class convolves n input channels with m filter coefficient sets and returns n∗m output
channels.
The maximal number of coefficients can be FFT length - fragsize + 1.

4.59.2
4.59.2.1

Constructor & Destructor Documentation
MHAFilter::fftfilterbank_t::fftfilterbank_t ( unsigned int fragsize, unsigned int inputchannels,
unsigned int firchannels, unsigned int fftlen )

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CONTENTS

Parameters
fragsize

Number of frames expected in input signal (each cycle).

inputchannels

Number of channels expected in input signal.

firchannels

Number of channels expected in FIR filter coefficients (= number of bands).

fftlen

FFT length of filter.

The number of output channels is inputchannels∗firchannels.

4.59.3

Member Function Documentation

4.59.3.1

void MHAFilter::fftfilterbank_t::update_coeffs ( const mha_wave_t ∗ h )

Parameters
h

Coefficients structure

Note
The number of channels in h must match the number of channels given in the constructor,
and the number of frames can not be more than fftlen-fragsize+1.

4.59.3.2

void MHAFilter::fftfilterbank_t::filter ( const mha_wave_t ∗ s_in, mha_wave_t ∗∗ s_out,
const mha_wave_t ∗ h )

Parameters
Input signal pointer.

s←_in

Return values
s_out

Pointer to output signal pointer, will be set to a valid signal

Parameters
h

FIR coefficients

4.59.3.3

void MHAFilter::fftfilterbank_t::filter ( const mha_wave_t ∗ s_in, mha_wave_t ∗∗ s_out )

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MHAFilter::filter_t Class Reference

165

Parameters
Input signal pointer.

s←_in

Return values
s_out

4.60

Pointer to output signal pointer, will be set to a valid signal

MHAFilter::filter_t Class Reference

Generic IIR filter class.
Inheritance diagram for MHAFilter::filter_t:

MHAFilter::filter_t

MHAFilter::diff_t

Public Member Functions
• filter_t (unsigned int ch, unsigned int lena, unsigned int lenb)
Constructor.

• filter_t (unsigned int ch, const std::vector< mha_real_t > &vA, const std::vector< mha←_real_t > &vB)
Constructor with initialization of coefficients.

• void filter (mha_wave_t ∗out, const mha_wave_t ∗in)
Filter all channels in a waveform structure.

• void filter (mha_real_t ∗dest, const mha_real_t ∗src, unsigned int dframes, unsigned
int frame_dist, unsigned int channel_dist, unsigned int channel_begin, unsigned int
channel_end)
Filter parts of a waveform structure.

• mha_real_t filter (mha_real_t x, unsigned int ch)
Filter one sample.

• unsigned int get_len_A () const
Return length of recursive coefficients.

• unsigned int get_len_B () const
Return length of non-recursive coefficients.
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CONTENTS

Public Attributes
• double ∗ A
Pointer to recursive coefficients.

• double ∗ B
Pointer to non-recursive coefficients.

4.60.1

Detailed Description

This class implements a generic multichannel IIR filter. It is realized as direct form II. It can
work on any float array or on mha_wave_t (p. 154) structs. The filter coefficients can be directly
accessed.

4.60.2

Constructor & Destructor Documentation

4.60.2.1

MHAFilter::filter_t::filter_t ( unsigned int ch, unsigned int lena, unsigned int lenb )

Parameters
Number of channels
Number of recursive coefficients
Number of non-recursive coefficients

ch
lena
lenb

4.60.2.2

MHAFilter::filter_t::filter_t ( unsigned int ch, const std::vector< mha_real_t > & vA, const
std::vector< mha_real_t > & vB )

Parameters
ch
vA
vB

Number of channels.
Recursive coefficients.
Non-recursive coefficients.

4.60.3
4.60.3.1

Member Function Documentation
void MHAFilter::filter_t::filter ( mha_wave_t ∗ out, const mha_wave_t ∗ in )

Parameters
out
in

Output signal
Input signal

© 2005-2018 HörTech gGmbH, Oldenburg

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MHAFilter::gamma_flt_t Class Reference

4.60.3.2

167

void MHAFilter::filter_t::filter ( mha_real_t ∗ dest, const mha_real_t ∗ src, unsigned int
dframes, unsigned int frame_dist, unsigned int channel_dist, unsigned int channel_begin,
unsigned int channel_end )

Parameters
dest
src

Output signal.
Input signal.

dframes
frame_dist
channel_dist
channel_begin

Number of frames to be filtered.
Index distance between frames of one channel
Index distance between audio channels
Number of first channel to be processed

channel_end

Number of last channel to be processed

4.60.3.3 mha_real_t MHAFilter::filter_t::filter ( mha_real_t x, unsigned int ch )
Parameters
x

Input value

ch

Channel number to use in filter state

4.61

MHAFilter::gamma_flt_t Class Reference

Class for gammatone filter.

Public Member Functions
• gamma_flt_t (std::vector< mha_real_t > cf, std::vector< mha_real_t > bw, mha_real←_t srate, unsigned int order)
Constructor.

• void operator() (mha_wave_t &X, mha_spec_t &Y)
Filter method.

• void operator() (mha_wave_t &X, mha_wave_t &Yre, mha_wave_t &Yim)
Filter method.

• void operator() (mha_wave_t &Yre, mha_wave_t &Yim, unsigned int stage)
Filter method for specific stage.

4.61.1
4.61.1.1

Constructor & Destructor Documentation
MHAFilter::gamma_flt_t::gamma_flt_t ( std::vector< mha_real_t > cf, std::vector<
mha_real_t > bw, mha_real_t srate, unsigned int order )

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CONTENTS

Parameters
cf

Center frequency in Hz.

bw

Bandwidth in Hz (same number of entries as in cf).

srate
order

Sampling frequency in Hz.
Filter order.

4.62

MHAFilter::iir_filter_t Class Reference

IIR filter class wrapper for integration into parser structure.
Inheritance diagram for MHAFilter::iir_filter_t:

MHAParser::base_t

MHAParser::parser_t

MHAPlugin::config_t
< iir_filter_state_t >

MHAFilter::iir_filter_t

Public Member Functions
• iir_filter_t (std::string help="IIR filter structure", std::string def_A="[1]", std::string def_←B="[1]", unsigned int channels=1)
Constructor of the IIR filter.

• void filter (mha_wave_t ∗y, const mha_wave_t ∗x)
The filter processes the audio signal.

• mha_real_t filter (mha_real_t x, unsigned int ch)
Filter a single audio sample.

• void resize (unsigned int channels)
Change the number of channels after object creation.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAFilter::iir_filter_t Class Reference

169

Additional Inherited Members
4.62.1

Detailed Description

This class implements an infinite impulse response filter. Since it inherits from MHAParser←::parser_t (p. 220), it can easily be integrated in the openMHA configuration tree. It provides
the configuration language variables "A" (vector of recursive filter coefficients) and "B" (vector
of non-recursive filter coefficients).
The filter instance reacts to changes in filter coefficients through the openMHA configuration
language, and uses the updated coefficients in the next invocation of the filter method.
Update of the coefficients is thread-safe and non-blocking. Simply add this subparser to your
parser items and use the "filter" member function. Filter states are reset to all 0 on update.

4.62.2
4.62.2.1

Constructor & Destructor Documentation
MHAFilter::iir_filter_t::iir_filter_t ( std::string help = "IIR filter structure", std::string
def_A = "[1]", std::string def_B = "[1]", unsigned int channels = 1 )

Initialises the sub-parser structure and the memory for holding the filter's state.
Parameters
help

The help string for the parser that groups the configuration variables of this filter.
Could be used to describe the purpose of this IIR filter.

def_A

The initial value of the vector of the recursive filter coefficients, represented as
string.

def_B

The initial value of the vector of the non-recursive filter coefficients, represented
as string.

channels

The number of indipendent audio channels to process with this filter. Needed to
allocate a state vector for each audio channel.

4.62.3
4.62.3.1

Member Function Documentation
void MHAFilter::iir_filter_t::filter ( mha_wave_t ∗ y, const mha_wave_t ∗ x )

All channels in the audio signal are processed using the same filter coefficients. Indipendent
state is stored between calls for each audio channel.

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CONTENTS

Parameters
y

Pointer to output signal holder. The output signal is stored here. Has to have the same
signal dimensions as the input signal x. In-place processing (y and x pointing to the
same signal holder) is possible.

x

Pointer to input signal holder. Number of channels has to be the same as given to the
constructor, or to the resize (p. 170) method.

4.62.3.2 mha_real_t MHAFilter::iir_filter_t::filter ( mha_real_t x, unsigned int ch )
Parameters
x

The single audio sample

ch

Zero-based channel index. Use and change the state of channel ch. ch has to be less
than the number of channels given to the constructor or the resize (p. 170) method.

Returns
the filtered result sample.

4.62.3.3

void MHAFilter::iir_filter_t::resize ( unsigned int channels )

Parameters
channels

4.63

The new number of channels. Old filter states are lost.

MHAFilter::iir_ord1_real_t Class Reference

First order recursive filter.

Public Member Functions
• iir_ord1_real_t (std::vector< mha_real_t > A, std::vector< mha_real_t > B)
Constructor with filter coefficients (one per channel)

• iir_ord1_real_t (std::vector< mha_real_t > tau, mha_real_t srate)
Constructor for low pass filter (one time constant per channel)

• mha_real_t operator() (unsigned int ch, mha_real_t x)
Filter method for real value input, one element.

• mha_complex_t operator() (unsigned int ch, mha_complex_t x)
Filter method for complex input, one element.

• void operator() (const mha_wave_t &X, mha_wave_t &Y)
Filter method for real value input.

• void operator() (const mha_spec_t &X, mha_spec_t &Y)
© 2005-2018 HörTech gGmbH, Oldenburg

4.64

MHAFilter::o1_ar_filter_t Class Reference

171

Filter method for complex value input.

• void operator() (const mha_wave_t &Xre, const mha_wave_t &Xim, mha_wave_t &Yre,
mha_wave_t &Yim)
Filter method for complex value input.

4.64

MHAFilter::o1_ar_filter_t Class Reference

First order attack-release lowpass filter.
Inheritance diagram for MHAFilter::o1_ar_filter_t:

mha_wave_t

MHASignal::waveform_t

MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAFilter::o1flt_maxtrack_t

MHAFilter::o1flt_mintrack_t

Public Member Functions
• o1_ar_filter_t (unsigned int channels, mha_real_t fs=1.0f, std::vector< mha_real_t >
tau_a=std::vector< float >(1, 0.0f), std::vector< mha_real_t > tau_r=std::vector< float
>(1, 0.0f))
Constructor, setting all taus to zero.

• void set_tau_attack (unsigned int ch, mha_real_t tau)
Set the attack time constant.

• void set_tau_release (unsigned int ch, mha_real_t tau)
Set the release time constant.

• mha_real_t operator() (unsigned int ch, mha_real_t x)
Apply filter to value x, using state channel ch.

• void operator() (const mha_wave_t &in, mha_wave_t &out)
Apply filter to a mha_wave_t ( p. 154) data.
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CONTENTS

Additional Inherited Members
4.64.1

Detailed Description

This filter is the base of first order lowpass filter, maximum tracker and minimum tracker.

4.64.2
4.64.2.1

Constructor & Destructor Documentation
MHAFilter::o1_ar_filter_t::o1_ar_filter_t ( unsigned int channels, mha_real_t fs = 1.0f,
std::vector< mha_real_t > tau_a = std::vector(1,0.0f), std::vector<
mha_real_t > tau_r = std::vector(1,0.0f) )

The filter state can be accessed through the member functions of MHASignal::waveform_t
(p. 268).
Parameters
channels

Number of independent filters

fs

Sampling rate (optional, default = 1)

tau_a

Attack time constants (optional, default = 0)

tau_r

Release time constants (optional, default = 0)

4.64.3
4.64.3.1

Member Function Documentation
void MHAFilter::o1_ar_filter_t::set_tau_attack ( unsigned int ch, mha_real_t tau )

Parameters
ch
tau

4.64.3.2

Channel number
Time constant

void MHAFilter::o1_ar_filter_t::set_tau_release ( unsigned int ch, mha_real_t tau )

Parameters
ch
tau

Channel number
Time constant

4.64.3.3 mha_real_t MHAFilter::o1_ar_filter_t::operator() ( unsigned int ch, mha_real_t x )
[inline]

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MHAFilter::o1flt_lowpass_t Class Reference

173

Parameters
ch
x

Cannel number
Input value

Returns
Output value

4.64.3.4

void MHAFilter::o1_ar_filter_t::operator() ( const mha_wave_t & in, mha_wave_t & out )
[inline]

Parameters
in

Input signal

out

Output signal

The number of channels must match the number of filter bands.

4.65

MHAFilter::o1flt_lowpass_t Class Reference

First order low pass filter.
Inheritance diagram for MHAFilter::o1flt_lowpass_t:

mha_wave_t

MHASignal::waveform_t

MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAFilter::o1flt_maxtrack_t

© 2005-2018 HörTech gGmbH, Oldenburg

MHAFilter::o1flt_mintrack_t

174

CONTENTS

Public Member Functions
• o1flt_lowpass_t (const std::vector< mha_real_t > &, mha_real_t, mha_real_t=0)
Constructor of low pass filter, sets sampling rate and time constants.

• void set_tau (unsigned int ch, mha_real_t tau)
change the time constant in one channel

• void set_tau (mha_real_t tau)
set time constant in all channels to tau

Additional Inherited Members
4.65.1

Constructor & Destructor Documentation

4.65.1.1

MHAFilter::o1flt_lowpass_t::o1flt_lowpass_t ( const std::vector< mha_real_t > & tau,
mha_real_t fs, mha_real_t startval = 0 )

Parameters
tau
fs
startval

4.66

Vector of time constants
Sampling rate
Initial internal state value

MHAFilter::o1flt_maxtrack_t Class Reference

First order maximum tracker.
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4.66

MHAFilter::o1flt_maxtrack_t Class Reference

175

Inheritance diagram for MHAFilter::o1flt_maxtrack_t:

mha_wave_t

MHASignal::waveform_t

MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAFilter::o1flt_maxtrack_t

Public Member Functions
• o1flt_maxtrack_t (const std::vector< mha_real_t > &, mha_real_t, mha_real_t=0)
Constructor of low pass filter, sets sampling rate and time constants.

• void set_tau (unsigned int ch, mha_real_t tau)
change the time constant in one channel

• void set_tau (mha_real_t tau)
set time constant in all channels to tau

Additional Inherited Members
4.66.1

Detailed Description

4.66.2

Constructor & Destructor Documentation

4.66.2.1

MHAFilter::o1flt_maxtrack_t::o1flt_maxtrack_t ( const std::vector< mha_real_t > & tau,
mha_real_t fs, mha_real_t startval = 0 )

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CONTENTS

Parameters
tau
fs
startval

4.67

Vector of time constants
Sampling rate
Initial internal state value

MHAFilter::o1flt_mintrack_t Class Reference

First order minimum tracker.
Inheritance diagram for MHAFilter::o1flt_mintrack_t:

mha_wave_t

MHASignal::waveform_t

MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAFilter::o1flt_mintrack_t

Public Member Functions
• void set_tau (unsigned int ch, mha_real_t tau)
change the time constant in one channel

• void set_tau (mha_real_t tau)
set time constant in all channels to tau
© 2005-2018 HörTech gGmbH, Oldenburg

4.68

MHAFilter::partitioned_convolution_t Class Reference

177

Additional Inherited Members
4.67.1

4.68

Detailed Description

MHAFilter::partitioned_convolution_t Class Reference

A filter class for partitioned convolution.

Classes
• struct index_t
Bookkeeping class.

Public Member Functions
• partitioned_convolution_t (unsigned int fragsize, unsigned int nchannels_in, unsigned
int nchannels_out, const transfer_matrix_t &transfer)
Create a new partitioned convolver.

• ∼partitioned_convolution_t ()
Free fftw resource allocated in constructor.

• mha_wave_t ∗ process (const mha_wave_t ∗s_in)
processing

Public Attributes
• unsigned int fragsize
Audio fragment size, always equal to partition size.

• unsigned int nchannels_in
Number of audio input channels.

• unsigned int nchannels_out
Number of audio output channels.

• unsigned int output_partitions
The maximum number of partitions in any of the impulse responses.

• unsigned int filter_partitions
The total number of non-zero impulse response partitions.

• MHASignal::waveform_t input_signal_wave
Buffer for input signal.

• unsigned int current_input_signal_buffer_half_index
A counter modulo 2.

• MHASignal::spectrum_t input_signal_spec
Buffer for FFT transformed input signal.

• MHASignal::spectrum_t frequency_response
Buffers for frequency response spectra of impulse response partitions.
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CONTENTS

• std::vector< index_t > bookkeeping
Keeps track of input channels, output channels, impulse response partition, and delay.

• std::vector< MHASignal::spectrum_t > output_signal_spec
Buffers for FFT transformed output signal.

• unsigned int current_output_partition_index
A counter modulo output_partitions, indexing the "current" output partition.

• MHASignal::waveform_t output_signal_wave
Buffer for the wave output signal.

• mha_fft_t fft
The FFT transformer.

4.68.1

Detailed Description

Impulse responses are partitioned into sections of fragment size. Audio signal is convolved with
every partition and delayed as needed. Convolution is done according to overlap-save. FFT
length used is 2 times fragment size.

4.68.2

Constructor & Destructor Documentation

4.68.2.1

MHAFilter::partitioned_convolution_t::partitioned_convolution_t ( unsigned int fragsize,
unsigned int nchannels_in, unsigned int nchannels_out, const transfer_matrix_t & transfer
)

Parameters
fragsize

Audio fragment size, equal to partition size.

nchannels_in

Number of input audio channels.

nchannels_out

Number of output audio channels.

transfer

A sparse matrix of impulse responses.

4.68.3

Member Data Documentation

4.68.3.1

unsigned int MHAFilter::partitioned_convolution_t::fragsize

4.68.3.2

unsigned int MHAFilter::partitioned_convolution_t::nchannels_in

4.68.3.3

unsigned int MHAFilter::partitioned_convolution_t::nchannels_out

4.68.3.4

unsigned int MHAFilter::partitioned_convolution_t::output_partitions

Determines the size if the delay line.
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4.69 MHAFilter::partitioned_convolution_t::index_t Struct
Reference
4.68.3.5

179

unsigned int MHAFilter::partitioned_convolution_t::filter_partitions

4.68.3.6 MHASignal::waveform_t MHAFilter::partitioned_convolution_t::input_signal_wave
Has nchannels_in channels and fragsize∗2 frames
4.68.3.7

unsigned int MHAFilter::partitioned_convolution_t::current_input_signal_buffer_half_index

Indicates the buffer half in input signal wave into which to copy the current input signal.
4.68.3.8 MHASignal::spectrum_t MHAFilter::partitioned_convolution_t::input_signal_spec
Has nchannels_in channels and fragsize+1 frames (fft bins).
4.68.3.9 MHASignal::spectrum_t MHAFilter::partitioned_convolution_t::frequency_response
Each "channel" contains another partition of some impulse response. The bookkeeping array
is used to keep track what to do with these frequency responses. This container has filter_←partitions channels and fragsize+1 frames (fft bins).
4.68.3.10

std::vector MHAFilter::partitioned_convolution_t::bookkeeping

The index into this array is the same as the "channel" index into the frequency_response array.
Array has filter_partitions entries.
4.68.3.11

std::vector MHAFilter::partitioned_convolution_t::output_←signal_spec

For each array member, Number of channels is equal to nchannels_out, number of frames (fft
bins) is equal to fragsize+1. Array size is equal to output_partitions.
4.68.3.12

unsigned int MHAFilter::partitioned_convolution_t::current_output_partition_index

4.68.3.13 MHASignal::waveform_t MHAFilter::partitioned_convolution_t::output_signal_wave
Number of channels is equal to nchannels_out, number of frames is equal to fragsize

4.69

MHAFilter::partitioned_convolution_t::index_t Struct Reference

Bookkeeping class.
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CONTENTS

Public Member Functions
• index_t (unsigned int src, unsigned int tgt, unsigned int dly)
Data constructor.

• index_t ()
Default constructor for STL compatibility.

Public Attributes
• unsigned int source_channel_index
The input channel index to apply the current partition to.

• unsigned int target_channel_index
The index of the output channel to which the filter result should go.

• unsigned int delay
The delay (in blocks) of this partition.

4.69.1

Detailed Description

For each impulse response partition, keeps track of which input to filter, which output channel
to filter to, and the delay in blocks. Objects of class Index should be kept in an array with the
same indices as the corresponding inpulse response partitions.

4.69.2

Constructor & Destructor Documentation

4.69.2.1

MHAFilter::partitioned_convolution_t::index_t::index_t ( unsigned int src, unsigned int tgt,
unsigned int dly ) [inline]

Parameters
src

The input channel index to apply the current partition to.

tgt

The index of the output channel to which the filter result should go.

dly

The delay (in blocks) of this partition

4.69.3

Member Data Documentation

4.69.3.1

unsigned int MHAFilter::partitioned_convolution_t::index_t::source_channel_index

4.69.3.2

unsigned int MHAFilter::partitioned_convolution_t::index_t::target_channel_index

4.70

MHAFilter::polyphase_resampling_t Class Reference

A class that does polyphase resampling.
© 2005-2018 HörTech gGmbH, Oldenburg

4.70

MHAFilter::polyphase_resampling_t Class Reference

181

Public Member Functions
• polyphase_resampling_t (unsigned n_up, unsigned n_down, mha_real_t nyquist_ratio,
unsigned n_irs, unsigned n_ringbuffer, unsigned n_channels, unsigned n_prefill)
Initialize a polyphase resampler.

• void write (mha_wave_t &signal)
Write signal to the ringbuffer.

• void read (mha_wave_t &signal)
Read resampled signal.

• unsigned readable_frames () const
Number of frames at target sampling rate that can be produced.

Private Attributes
• unsigned upsampling_factor
Interpolation rate / source rate.

• unsigned downsampling_factor
Interpolation rate / target rate.

• unsigned now_index
points to "now" in the interpolated sampling rate

• bool underflow
indicates if an underflow has occurred. Object cannot be used then.

• MHAWindow::hanning_t impulse_response
contains the lowpass impulse response at interpolation rate

• MHASignal::ringbuffer_t ringbuffer
storage of input signal

4.70.1

Detailed Description

4.70.2

Constructor & Destructor Documentation

4.70.2.1

MHAFilter::polyphase_resampling_t::polyphase_resampling_t ( unsigned n_up, unsigned
n_down, mha_real_t nyquist_ratio, unsigned n_irs, unsigned n_ringbuffer, unsigned
n_channels, unsigned n_prefill )

Parameters
n_up

upsampling factor

n_down

downsampling factor

nyquist_ratio

low pass filter cutoff frequency relative to the nyquist frequency of the
smaller of the two sampling rates. Example values: 0.8, 0.9

n_irs

length of impulse response (in samples at interpolation rate)

length of ringbuffer, in samples at source sampling rate
audio channels count
Prefill the ringbuffer with this many zero frames in samples at source
© 2005-2018 HörTechsampling
gGmbH, Oldenburg
rate
n_ringbuffer
n_channels
n_prefill

182

4.70.3

CONTENTS

Member Function Documentation

4.70.3.1

void MHAFilter::polyphase_resampling_t::write ( mha_wave_t & signal )

Parameters
signal

input signal in original sampling rate

Exceptions
MHA_Error ( p. 132)

4.70.3.2

Raises exception if there is not enough room or if the number of
channels does not match.

void MHAFilter::polyphase_resampling_t::read ( mha_wave_t & signal )

Will perform the resampling and remove no longer needed samples from the input buffer.
Parameters
signal

buffer to write the resampled signal to.

Exceptions
MHA_Error ( p. 132)

4.70.3.3

Raises exception if there is not enough input signal or if the number
of channels is too high.

unsigned MHAFilter::polyphase_resampling_t::readable_frames ( ) const [inline]

Warning: This method only checks for enough future samples present, therefore, this number
can be positive and a read operation can still fail if there are not enough past samples present
to perform the filtering for the first output sample.

4.71

MHAFilter::resampling_filter_t Class Reference

Hann shaped low pass filter for resampling.
© 2005-2018 HörTech gGmbH, Oldenburg

4.72

MHAFilter::smoothspec_t Class Reference

183

Inheritance diagram for MHAFilter::resampling_filter_t:

MHAFilter::fftfilter_t

MHAFilter::resampling
_filter_t

Public Member Functions
• resampling_filter_t (unsigned int fftlen, unsigned int irslen, unsigned int channels, unsigned int Nup, unsigned int Ndown, double fCutOff)
Constructor.

4.71.1

Detailed Description

This class uses FFT filter at upsampled rate.

4.71.2

Constructor & Destructor Documentation

4.71.2.1

MHAFilter::resampling_filter_t::resampling_filter_t ( unsigned int fftlen, unsigned int irslen,
unsigned int channels, unsigned int Nup, unsigned int Ndown, double fCutOff )

Parameters
fftlen

FFT length.

irslen

Length of filter.

channels
Nup
Ndown

Number of channels to be filtered.
Upsampling ratio.
Downsampling ratio.

fCutOff

Cut off frequency (relative to lower Nyquist Frequency)

4.72

MHAFilter::smoothspec_t Class Reference

Smooth spectral gains, create a windowed impulse response.
© 2005-2018 HörTech gGmbH, Oldenburg

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CONTENTS

Public Member Functions
• smoothspec_t (unsigned int fftlen, unsigned int nchannels, const MHAWindow::base←_t &window, bool minphase, bool linphase_asym=false)
Constructor.

• void smoothspec (const mha_spec_t &s_in, mha_spec_t &s_out)
Create a smoothed spectrum.

• void smoothspec (mha_spec_t &spec)
Create a smoothed spectrum (in place)

• void spec2fir (const mha_spec_t &spec, mha_wave_t &fir)
Return FIR coefficients.

4.72.1

Detailed Description

Spectral gains are smoothed by multiplicating the impulse response with a window function.
If a minimal phase is used, then the original phase is discarded and replaced by the minimal
phase function. In this case, the window is applied to the beginning of the inverse Fourier
transform of the input spectrum, and the remaining signal set to zero. If the original phase
is kept, the window is applied symmetrical arround zero, i.e. to the first and last samples of
the inverse Fourier transform of the input spectrum. The spec2fir() (p. 185) function creates a
causal impulse response by circular shifting the impulse response by half of the window length.
The signal dimensions of the arguments of smoothspec() (p. 184) must correspond to the FFT
length and number of channels provided in the constructor. The function spec2fir() (p. 185)
can fill signal structures with more than window length frames.

4.72.2

Constructor & Destructor Documentation

4.72.2.1

MHAFilter::smoothspec_t::smoothspec_t ( unsigned int fftlen, unsigned int nchannels, const
MHAWindow::base_t & window, bool minphase, bool linphase_asym = false )

Parameters
fftlen

FFT length of input spectrum (fftlen/2+1 bins)

nchannels

Number of channels in input spectrum

window

Window used for smoothing

minphase

Use minimal phase (true) or original phase (false)

linphase_asym

Keep phase, but apply full window at beginning of IRS

4.72.3
4.72.3.1

Member Function Documentation
void MHAFilter::smoothspec_t::smoothspec ( const mha_spec_t & s_in, mha_spec_t &
s_out )

© 2005-2018 HörTech gGmbH, Oldenburg

4.73

MHAFilter::transfer_function_t Struct Reference

185

Parameters
Input spectrum

s←_in

Return values
s_out

4.72.3.2

Output spectrum

void MHAFilter::smoothspec_t::smoothspec ( mha_spec_t & spec ) [inline]

Parameters
Spectrum to be smoothed.

spec

4.72.3.3

void MHAFilter::smoothspec_t::spec2fir ( const mha_spec_t & spec, mha_wave_t & fir )

Parameters
spec

Input spectrum

Return values
FIR coefficients, minimum length is window length

fir

4.73

MHAFilter::transfer_function_t Struct Reference

a structure containing a source channel number, a target channel number, and an impulse
response.

Public Member Functions
• transfer_function_t ()
Default constructor for STL conformity.

• transfer_function_t (unsigned int source_channel_index, unsigned int target_←channel_index, const std::vector< float > &impulse_response)
Data constructor.

• unsigned int partitions (unsigned int fragsize) const
for the given partition size, return the number of partitions of the impulse response.

• unsigned int non_empty_partitions (unsigned int fragsize) const
for the given partition size, return the number of non-empty partitions of the impulse response.

• bool isempty (unsigned int fragsize, unsigned int index) const
checks if the partition contains only zeros
© 2005-2018 HörTech gGmbH, Oldenburg

186

CONTENTS

Public Attributes
• unsigned int source_channel_index
Source audio channel index for this transfer function.

• unsigned int target_channel_index
Target audio channel index for this transfer function.

• std::vector< float > impulse_response
Impulse response of transfer from source to target channel.

4.73.1

Constructor & Destructor Documentation

4.73.1.1

MHAFilter::transfer_function_t::transfer_function_t ( ) [inline]

Not used.
4.73.1.2

MHAFilter::transfer_function_t::transfer_function_t ( unsigned int source_channel_index,
unsigned int target_channel_index, const std::vector< float > & impulse_response )

Parameters
source_channel_index
target_channel_index

Source audio channel index for this transfer function
Target audio channel index for this transfer function

impulse_response

Impulse response of transfer from source to target channel

4.73.2

Member Function Documentation

4.73.2.1

unsigned int MHAFilter::transfer_function_t::partitions ( unsigned int fragsize ) const
[inline]

Parameters
fragsize

partition size

Returns
number of partitions occupied by the impulse response

4.73.2.2

unsigned int MHAFilter::transfer_function_t::non_empty_partitions ( unsigned int fragsize )
const [inline]

Parameters
fragsize

partition size

© 2005-2018 HörTech gGmbH, Oldenburg

4.74

MHAFilter::transfer_matrix_t Struct Reference

187

Returns
the number of non-empty partitions of the impulse response, i.e. partitions containing
only zeros are not counted.

4.73.2.3

bool MHAFilter::transfer_function_t::isempty ( unsigned int fragsize, unsigned int index ) const
[inline]

Parameters
fragsize
index

partition size
partition index

Returns
true when this partition of the impulse response contains only zeros.

4.74

MHAFilter::transfer_matrix_t Struct Reference

A sparse matrix of transfer function partitionss.
Inherits vector< transfer_function_t >.

Public Member Functions
• std::valarray< unsigned int > partitions (unsigned fragsize) const
Returns an array of the results of calling the partitions() ( p. 187) method on every matrix
member.

• std::valarray< unsigned int > non_empty_partitions (unsigned int fragsize) const
Returns an array of the results of calling the non_empty_partitions() ( p. 187) method on every
matrix member.

4.74.1

Detailed Description

Each matrix element knows its position in the matrix, so they can be stored as a vector.
© 2005-2018 HörTech gGmbH, Oldenburg

188

4.75

CONTENTS

MHAIOJack::io_jack_t Class Reference

Main class for JACK IO.
Inheritance diagram for MHAIOJack::io_jack_t:

MHAParser::base_t

MHAParser::parser_t

MHAJack::client_t

MHAIOJack::io_jack_t

Public Member Functions
• void prepare (int, int)
Allocate buffers, activate JACK client and install internal ports.

Private Member Functions
• void reconnect_inports ()
Connect the input ports when connection variable is accessed.

• void reconnect_outports ()
Connect the output ports when connection variable is accessed.

Additional Inherited Members

4.75.1

Detailed Description

This class registers a JACK client. JACK and framework states are managed by this class.
© 2005-2018 HörTech gGmbH, Oldenburg

4.76

MHAJack::client_avg_t Class Reference

4.75.2

Member Function Documentation

4.75.2.1

void io_jack_t::prepare ( int nch_in, int nch_out )

4.75.2.2

void io_jack_t::reconnect_inports ( ) [private]

4.75.2.3

void io_jack_t::reconnect_outports ( ) [private]

4.76

189

MHAJack::client_avg_t Class Reference

Generic JACK client for averaging a system response across time.
Inheritance diagram for MHAJack::client_avg_t:

MHAJack::client_t

MHAJack::client_avg_t

Public Member Functions
• client_avg_t (const std::string &name, const unsigned int &nrep_)
Constructor for averaging client.

• void io (mha_wave_t ∗s_out, mha_wave_t ∗s_in, const std::vector< std::string > &p_←out, const std::vector< std::string > &p_in, float ∗srate=NULL, unsigned int ∗fragsize=N←ULL)
Recording function.

4.76.1

Detailed Description

4.76.2

Constructor & Destructor Documentation

4.76.2.1

MHAJack::client_avg_t::client_avg_t ( const std::string & name_, const unsigned int & nrep_ )

© 2005-2018 HörTech gGmbH, Oldenburg

190

CONTENTS

Parameters
name←- Name of JACK client
_
nrep←- Number of repetitions
_

4.76.3

Member Function Documentation

4.76.3.1

void MHAJack::client_avg_t::io ( mha_wave_t ∗ is_out, mha_wave_t ∗ is_in, const
std::vector< std::string > & p_out, const std::vector< std::string > & p_in, float ∗ srate =
NULL, unsigned int ∗ fragsize = NULL )

long-description
Parameters
is_out

Input (test) signal, which will be repeated

is_in
p_out

System response (averaged, same length as input required)
Ports to play back the test signal

p_in

Ports to record from the system response

srate

Pointer to sampling rate variable, will be filled with server sampling rate

fragsize

Pointer to fragment size variable, will be filled with server fragment size

4.77

MHAJack::client_noncont_t Class Reference

Generic client for synchronous playback and recording of waveform fragments.
Inheritance diagram for MHAJack::client_noncont_t:

MHAJack::client_t

MHAJack::client_noncont_t

© 2005-2018 HörTech gGmbH, Oldenburg

4.78

MHAJack::client_t Class Reference

191

Additional Inherited Members

4.78

MHAJack::client_t Class Reference

Generic asynchronous JACK client.
Inheritance diagram for MHAJack::client_t:

MHAJack::client_t

MHAIOJack::io_jack_t

MHAJack::client_avg_t

MHAJack::client_noncont_t

Public Member Functions
• void prepare (const std::string &client_name, const unsigned int &nchannels_in, const
unsigned int &nchannels_out)
Allocate buffers, activate JACK client and install internal ports.

• void prepare (const std::string &server_name, const std::string &client_name, const unsigned int &nchannels_in, const unsigned int &nchannels_out)
Allocate buffers, ports, and activates JACK client.

• void release ()
Remove JACK client and deallocate internal ports and buffers.

• void connect_input (const std::vector< std::string > &)
Connect the input ports when connection variable is accessed.

• void connect_output (const std::vector< std::string > &)
Connect the output ports when connection variable is accessed.

• void get_ports (std::vector< std::string > &, unsigned long jack_flags)
Get a list of Jack ports.

Private Member Functions
• void prepare_impl (const char ∗server_name, const char ∗client_name, const unsigned
int &nchannels_in, const unsigned int &nchannels_out)
Allocate buffers, activate JACK client and allocates jack ports Registers the jack client with the
given server and activates it.

• int jack_proc_cb (jack_nframes_t)
This is the main processing callback.
© 2005-2018 HörTech gGmbH, Oldenburg

192

4.78.1

Detailed Description

4.78.2

Member Function Documentation

4.78.2.1

CONTENTS

void MHAJack::client_t::prepare ( const std::string & client_name, const unsigned int & nch_in,
const unsigned int & nch_out )

Registers the jack client with the default jack server and activates it.
Parameters
client_name
nch_in

Name of this jack client
Input ports to register

nch_out

Output ports to register

4.78.2.2

void MHAJack::client_t::prepare ( const std::string & server_name, const std::string &
client_name, const unsigned int & nch_in, const unsigned int & nch_out )

Registers the jack client with specified jack server and activates it.
Parameters
server_name

Name of the jack server to register with

client_name
nch_in

Name of this jack client
Input ports to register

nch_out

Output ports to register

4.78.2.3

void MHAJack::client_t::release ( )

4.78.2.4

void MHAJack::client_t::connect_input ( const std::vector< std::string > & con )

4.78.2.5

void MHAJack::client_t::connect_output ( const std::vector< std::string > & con )

4.78.2.6

void MHAJack::client_t::get_ports ( std::vector< std::string > & res, unsigned long jack_flags
)

Parameters
res

Result string vector

jack_flags

Jack port flags (JackPortInput etc.)

© 2005-2018 HörTech gGmbH, Oldenburg

4.79

MHAJack::port_t Class Reference

4.78.2.7

193

void MHAJack::client_t::prepare_impl ( const char ∗ server_name, const char ∗ client_name,
const unsigned int & nch_in, const unsigned int & nch_out ) [private]

Parameters
server_name

Name of the jack server to register with

client_name
nch_in

Name of this jack client
Input ports to register

nch_out

Output ports to register

4.78.2.8

int MHAJack::client_t::jack_proc_cb ( jack_nframes_t n ) [private]

Here happens double buffering and downsampling.

4.79

MHAJack::port_t Class Reference

Class for one channel/port.

Public Member Functions
• port_t (jack_client_t ∗jc, dir_t dir, int id)
• port_t (jack_client_t ∗jc, dir_t dir, const std::string &id)
Constructor to create port with specific name.

•
•
•
•
•

void read (mha_wave_t ∗s, unsigned int ch)
void write (mha_wave_t ∗s, unsigned int ch)
void mute (unsigned int n)
void connect_to (const char ∗pn)
const char ∗ get_short_name ()
Return the port name.

4.79.1

Detailed Description

This class represents one JACK port. Double buffering for asynchronous process callbacks is
managed by this class.

4.79.2
4.79.2.1

Constructor & Destructor Documentation
MHAJack::port_t::port_t ( jack_client_t ∗ jc, dir_t dir, int id )

© 2005-2018 HörTech gGmbH, Oldenburg

194

CONTENTS

Parameters
jc

JACK client.

dir

Direction (input/output).

id

Number in port name (starting with 1).

4.79.2.2

MHAJack::port_t::port_t ( jack_client_t ∗ jc, dir_t dir, const std::string & id )

Parameters
jc

JACK client.

dir
id

Direction (input/output).
Port name.

4.79.3

Member Function Documentation

4.79.3.1

void MHAJack::port_t::read ( mha_wave_t ∗ s, unsigned int ch )

Parameters
s

Signal structure to store the audio data.

ch

Channel number in audio data structure to be used.

4.79.3.2

void MHAJack::port_t::write ( mha_wave_t ∗ s, unsigned int ch )

Parameters
s

Signal structure from which the audio data is read.

ch

Channel number in audio data structure to be used.

4.79.3.3

void MHAJack::port_t::mute ( unsigned int n )

Parameters
n

Number of samples to be muted (must be the same as reported by Jack processing
callback).

4.79.3.4

void MHAJack::port_t::connect_to ( const char ∗ pn )

Parameters
pn

Port name to connect to

© 2005-2018 HörTech gGmbH, Oldenburg

4.80

MHAMultiSrc::base_t Class Reference

4.80

MHAMultiSrc::base_t Class Reference

195

Base class for source selection.
Inheritance diagram for MHAMultiSrc::base_t:

MHAPlugin::config_t
< MHAMultiSrc::channels_t >

MHAMultiSrc::base_t

Public Member Functions
• void select_source (const std::vector< std::string > &src, int in_channels)
Change the selection of input sources.

4.80.1

Detailed Description

See also
MHAMultiSrc::channel_t
MHAMultiSrc::channels_t

4.80.2
4.80.2.1

Member Function Documentation
void MHAMultiSrc::base_t::select_source ( const std::vector< std::string > & src, int
in_channels )

This function is real-time and thread safe.
Parameters
src

List of input sources

in_channels

Number of input channels in direct input (the processed signal)

© 2005-2018 HörTech gGmbH, Oldenburg

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4.81

CONTENTS

MHAOvlFilter::fftfb_t Class Reference

FFT based overlapping filter bank.
Inheritance diagram for MHAOvlFilter::fftfb_t:

mha_wave_t

MHAOvlFilter::fspacing_t

MHASignal::waveform_t

MHAOvlFilter::fftfb_t

MHAOvlFilter::overlap
_save_filterbank_t

Public Member Functions
• fftfb_t (MHAOvlFilter::fftfb_vars_t &par, unsigned int nfft, mha_real_t fs)
Constructor for a FFT-based overlapping filter bank.

• unsigned int bin1 (unsigned int band) const
Return index of first non-zero filter shape window.

• unsigned int bin2 (unsigned int band) const
Return index of first zero filter shape window above center frequency.

• unsigned int get_fftlen () const
Return fft length.

• mha_real_t w (unsigned int k, unsigned int b) const
Return filter shape window at index k in band b.

Additional Inherited Members
4.81.1
4.81.1.1

Constructor & Destructor Documentation
MHAOvlFilter::fftfb_t::fftfb_t ( MHAOvlFilter::fftfb_vars_t & par, unsigned int nfft,
mha_real_t fs )

© 2005-2018 HörTech gGmbH, Oldenburg

4.82

MHAOvlFilter::fftfb_vars_t Class Reference

197

Parameters
par

Parameters for the FFT filterbank that can not be deduced from the signal dimensions
are taken from this set of configuration variables.

nfft

FFT length

fs

Sampling rate / Hz

4.81.2

Member Function Documentation

4.81.2.1 mha_real_t MHAOvlFilter::fftfb_t::w ( unsigned int k, unsigned int b ) const [inline]
Parameters
Frequency index
Band index

k
b

4.82

MHAOvlFilter::fftfb_vars_t Class Reference

Set of configuration variables for FFT-based overlapping filters.
Inherited by MHAOvlFilter::overlap_save_filterbank_t::vars_t.

Public Member Functions
• fftfb_vars_t (MHAParser::parser_t &p)
construct a set of openMHA configuration language variables suitable for configuring the FFTbased overlapping filterbank.

Public Attributes
• scale_var_t fscale
Frequency scale type (lin/bark/log/erb).

• scale_var_t ovltype
Filter shape (rect/lin/hann).

• MHAParser::float_t plateau
relative plateau width.

• MHAParser::kw_t ftype
Flag to decide wether edge or center frequencies are used.

• fscale_t f
Frequency.

• MHAParser::bool_t normalize
Normalize sum of channels.

• MHAParser::bool_t fail_on_nonmonotonic
© 2005-2018 HörTech gGmbH, Oldenburg

198

CONTENTS

Fail if frequency entries are non-monotonic (otherwise sort)

• MHAParser::bool_t fail_on_unique_bins
Fail if center frequencies share the same FFT bin.

• MHAParser::vfloat_mon_t cf
Final center frequencies in Hz.

• MHAParser::vfloat_mon_t ef
Final edge frequencies in Hz.

• MHAParser::vfloat_mon_t cLTASS
Bandwidth correction for LTASS noise (level of 0 dB RMS LTASS noise)

4.82.1

Detailed Description

This class enables easy configuration of the FFT-based overlapping filterbank. An instance of
fftfb_vars_t (p. 197) creates openMHA configuration language variables needed for configuring
the filterbank, and inserts these variables in the openMHA configuration tree.
This way, the variables are visible to the user and can be configured using the openMHA configuration language.

4.82.2

Constructor & Destructor Documentation

4.82.2.1

MHAOvlFilter::fftfb_vars_t::fftfb_vars_t ( MHAParser::parser_t & p )

Parameters
p

4.83

The node of the configuration tree where the variables created by this instance are
inserted.

MHAOvlFilter::fspacing_t Class Reference

Class for frequency spacing, used by filterbank shape generator class.
© 2005-2018 HörTech gGmbH, Oldenburg

4.84

MHAOvlFilter::overlap_save_filterbank_t Class Reference 199

Inheritance diagram for MHAOvlFilter::fspacing_t:

MHAOvlFilter::fspacing_t

MHAOvlFilter::fftfb_t

MHAOvlFilter::overlap
_save_filterbank_t

Public Member Functions
• unsigned int nbands () const
Return number of bands in filter bank.

4.84

MHAOvlFilter::overlap_save_filterbank_t Class Reference

A time-domain minimal phase filter bank with frequency shapes from MHAOvlFilter::fftfb_t
(p. 196).
Inheritance diagram for MHAOvlFilter::overlap_save_filterbank_t:

mha_wave_t

MHAOvlFilter::fspacing_t

MHASignal::waveform_t

MHAOvlFilter::fftfb_t

MHAFilter::fftfilterbank_t

MHAOvlFilter::overlap
_save_filterbank_t

© 2005-2018 HörTech gGmbH, Oldenburg

200

CONTENTS

Additional Inherited Members

4.85

MHAParser::base_t Class Reference

Base class for all parser items.
Inheritance diagram for MHAParser::base_t:

MHAParser::bool_mon_t

MHAParser::complex
_mon_t

MHAParser::float_mon_t

MHAParser::int_mon_t

MHAParser::commit_t
< receiver_t >

MHAParser::mcomplex
_mon_t

MHAParser::monitor_t

MHAParser::complex_t

MHAParser::mfloat_mon_t

MHAParser::bool_t

MHAParser::float_t

MHAParser::string_mon_t

MHAParser::kw_t

MHAParser::int_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::mcomplex_t

MHAParser::vcomplex
_mon_t

MHAParser::string_t

MHAParser::mfloat_t

MHAParser::vstring_t

MHAParser::vcomplex_t

MHAParser::vfloat_mon_t

MHAParser::vfloat_t

MHAParser::vint_mon_t

MHAParser::vint_t
MHAParser::vstring
_mon_t

MHAParser::base_t

AuditoryProfile::parser_t

DynComp::dc_afterburn
_vars_t

DynComp::dc_afterburn_t

io_file_t

io_parser_t

MHAParser::parser_t

io_tcp_parser_t

MHAFilter::adapt_filter_t

MHAFilter::iir_filter_t

MHAIOJack::io_jack_t

MHAParser::window_t

MHAPlugin::plugin_t
< runtime_cfg_t >

Public Member Functions
• base_t (const std::string &)
Constructor for base class of all parser nodes.

• virtual std::string parse (const std::string &)
Causes this node to process a command in the openMHA configuration language.

• virtual void parse (const char ∗, char ∗, unsigned int)
This function parses a command and writes the parsing result into a C character array.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::base_t Class Reference

201

• void set_node_id (const std::string &)
Set the identification string of this parser node.

• void set_help (const std::string &)
Set the help comment of a variable or parser.

• const std::string & fullname () const
Return the full dot-separated path name of this parser node in the openMHA configuration tree.

Public Attributes
• MHAEvents::emitter_t writeaccess
Event emitted on write access.

• MHAEvents::emitter_t valuechanged
Event emitted if the value has changed.

• MHAEvents::emitter_t readaccess
Event emitted on read access.

• MHAEvents::emitter_t prereadaccess
Event emitted on read access, before the data field is accessed.

4.85.1

Detailed Description

The key method of the parser base class is the std::string parse(const std::string&) (p. 201)
method. Parser proxy derivatives which overwrite any of the other parse() (p. 201) methods to
be the key method must make sure that the original parse() (p. 201) method utilizes the new
key method.

4.85.2

Constructor & Destructor Documentation

4.85.2.1

MHAParser::base_t::base_t ( const std::string & h )

Parameters
h

Help text describing this parser node. This help text is accessible to the configuration
language through the "?help" query command.

4.85.3

Member Function Documentation

4.85.3.1

std::string MHAParser::base_t::parse ( const std::string & cs ) [virtual]

Parameters
cs

The command to parse

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CONTENTS

Returns
The response to the command, if successful
Exceptions
MHA_Error ( p. 132)

4.85.3.2

If the command cannot be executed successfully. The reason for
failure is given in the message string of the exception.

void MHAParser::base_t::parse ( const char ∗ cmd, char ∗ retv, unsigned int len )
[virtual]

This base class implementation delegates to parse(const std::string &) (p. 201).
Parameters
cmd

Command to be parsed

retv
len

Buffer for the result
Length of buffer

4.85.3.3

void MHAParser::base_t::set_node_id ( const std::string & s )

The id can be queried from the configuration language using the ?id query command. Nodes
can be found by id using the ?listid query command on a containing parser node.
Parameters
s

The new identification string.

4.85.3.4

void MHAParser::base_t::set_help ( const std::string & s )

Parameters
s

New help comment.

4.85.3.5
4.85.4

const std::string & MHAParser::base_t::fullname ( ) const
Member Data Documentation

4.85.4.1 MHAEvents::emitter_t MHAParser::base_t::writeaccess
To connect a callback that is invoked on write access to this parser variable, use MHAEvents←::patchbay_t method connect(&writeaccess,&receiver_t::callback) where callback
is a method that expects no parameters and returns void.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::bool_mon_t Class Reference

203

4.85.4.2 MHAEvents::emitter_t MHAParser::base_t::valuechanged
To connect a callback that is invoked when write access to this parser variable actually changes
its value, use MHAEvents::patchbay_t method connect(&valuechanged,&receiver←_t::callback) where callback is a method that expects no parameters and returns void.
4.85.4.3 MHAEvents::emitter_t MHAParser::base_t::readaccess
To connect a callback that is invoked after the value of this variable has been read
through the configuration interface, use MHAEvents::patchbay_t method
connect(&readaccess,&receiver_t::callback) where callback is a method that expects no parameters and returns void.
4.85.4.4 MHAEvents::emitter_t MHAParser::base_t::prereadaccess
To connect a callback that is invoked when the value of this variable is about to be read through
the configuration interface, so that the callback can influence the value that is reported, use
MHAEvents::patchbay_t method connect(&prereadaccess,&receiver_t::callback)
where callback is a method that expects no parameters and returns void.

4.86

MHAParser::bool_mon_t Class Reference

Monitor with string value.
Inheritance diagram for MHAParser::bool_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::bool_mon_t

Public Member Functions
• bool_mon_t (const std::string &hlp)
Create a monitor variable for string values.
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CONTENTS

Public Attributes
• bool data
Data field.

4.86.1

Constructor & Destructor Documentation

4.86.1.1

MHAParser::bool_mon_t::bool_mon_t ( const std::string & hlp )

Parameters
hlp

4.87

A help text describing this monitor variable.

MHAParser::bool_t Class Reference

Variable with a boolean value ("yes"/"no")
Inheritance diagram for MHAParser::bool_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::bool_t

Public Member Functions
• bool_t (const std::string &help_text, const std::string &initial_value)
Constructor for a configuration language variable for boolean values.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::commit_t< receiver_t > Class Template Reference
205

Public Attributes
• bool data
Data field.

4.87.1

Constructor & Destructor Documentation

4.87.1.1

MHAParser::bool_t::bool_t ( const std::string & help_text, const std::string & initial_value )

Parameters
help_text

A human-readable text describing the purpose of this configuration variable.

initial_value

The initial value for this variable as a string. The string representation of 'true'
is either "yes" or "1". The string representation of 'false' is either "no" or "0".

4.88

MHAParser::commit_t< receiver_t > Class Template Reference

Parser variable with event-emission functionality.
Inheritance diagram for MHAParser::commit_t< receiver_t >:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::kw_t

MHAParser::commit_t
< receiver_t >

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CONTENTS

Additional Inherited Members
4.88.1

Detailed Description

template
class MHAParser::commit_t< receiver_t >
The commit_t (p. 205) variable can register an event receiver in its constructor, which is called
whenever the variable is set to "commit".

4.89

MHAParser::complex_mon_t Class Reference

Monitor with complex value.
Inheritance diagram for MHAParser::complex_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::complex
_mon_t

Public Member Functions
• complex_mon_t (const std::string &hlp)
Create a complex monitor variable.

Public Attributes
• mha_complex_t data
Data field.

4.89.1
4.89.1.1

Constructor & Destructor Documentation
MHAParser::complex_mon_t::complex_mon_t ( const std::string & hlp )

© 2005-2018 HörTech gGmbH, Oldenburg

4.90

MHAParser::complex_t Class Reference

Parameters
hlp

4.90

A help text describing this monitor variable.

MHAParser::complex_t Class Reference

Variable with complex value.
Inheritance diagram for MHAParser::complex_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::complex_t

Public Attributes
• mha_complex_t data
Data field.

Additional Inherited Members

4.91

MHAParser::float_mon_t Class Reference

Monitor with float value.
© 2005-2018 HörTech gGmbH, Oldenburg

207

208

CONTENTS

Inheritance diagram for MHAParser::float_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::float_mon_t

Public Member Functions
• float_mon_t (const std::string &hlp)
Initialize a floating point (32 bits) monitor variable.

Public Attributes
• float data
Data field.

4.91.1

Constructor & Destructor Documentation

4.91.1.1

MHAParser::float_mon_t::float_mon_t ( const std::string & hlp )

Parameters
hlp

4.92

A help text describing this monitor variable.

MHAParser::float_t Class Reference

Variable with float value.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::float_t Class Reference

209

Inheritance diagram for MHAParser::float_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::float_t

Public Member Functions
• float_t (const std::string &help_text, const std::string &initial_value, const std::string
&range="")
Constructor for a configuration language variable for 32bit ieee floating-point values.

Public Attributes
• float data
Data field.

Additional Inherited Members
4.92.1
4.92.1.1

Constructor & Destructor Documentation
MHAParser::float_t::float_t ( const std::string & help_text, const std::string & initial_value,
const std::string & range = "" )

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CONTENTS

Parameters
help_text

A human-readable text describing the purpose of this configuration variable.

initial_value

The initial value for this variable as a string (decimal representation of the
floating-point variable). If a range is given in the third parameter, then the
initial value has to be within the range. A human-readable text describing the
purpose of this configuration variable.

range

The range of values that this variable can hold can be restricted. A range is a
string of the form "[a,b]", where a and b are decimal representations of the
inclusive boundaries of the range. a<=b. In a range of the form "]a,b[", both
boundaries are excluded. Mixed forms are permitted. a or b can also be
omitted if there is no lower or upper limit. The range of values is always
restricted by the representable range of the underlying C data type.

4.93

MHAParser::int_mon_t Class Reference

Monitor variable with int value.
Inheritance diagram for MHAParser::int_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::int_mon_t

Public Member Functions
• int_mon_t (const std::string &hlp)
Create a monitor variable for integral values.

Public Attributes
• int data
Data field.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::int_t Class Reference

4.93.1

211

Detailed Description

Monitor variables can be of many types. These variables can be queried through the parser.
The public data element contains the monitored state. Write access is only possible from the
C++ code by direct access to the data field.

4.93.2

Constructor & Destructor Documentation

4.93.2.1

MHAParser::int_mon_t::int_mon_t ( const std::string & hlp )

Parameters
hlp

4.94

A help text describing this monitor variable.

MHAParser::int_t Class Reference

Variable with integer value.
Inheritance diagram for MHAParser::int_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::int_t

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CONTENTS

Public Member Functions
• int_t (const std::string &help_text, const std::string &initial_value, const std::string
&range="")
Constructor for a configuration language variable for integral values.

Public Attributes
• int data
Data field.

Additional Inherited Members
4.94.1

Constructor & Destructor Documentation

4.94.1.1

MHAParser::int_t::int_t ( const std::string & help_text, const std::string & initial_value, const
std::string & range = "" )

Parameters
help_text

A human-readable text describing the purpose of this configuration variable.

initial_value

The initial value for this variable as a string (decimal representation of the
integer variable). If a range is given in the third parameter, then the initial
value has to be within the range.

range

The range of values that this variable can hold can be restricted. A range is a
string of the form "[a,b]", where a and b are decimal representations of the
integral inclusive boundaries of the range. a<=b. In a range of the form
"]a,b[", both boundaries are excluded. Mixed forms are permitted. a or b can
also be omitted if there is no lower or upper limit. The range of values is
always restricted by the representable range of the underlying C data type
(usually 32 bits, [-2147483648,2147483647]).

4.95

MHAParser::keyword_list_t Class Reference

Keyword list class.

Public Member Functions
• void set_value (const std::string &)
Select a value from keyword list.

• void set_entries (const std::string &)
Set keyword list entries.
© 2005-2018 HörTech gGmbH, Oldenburg

4.95

MHAParser::keyword_list_t Class Reference

213

• const std::string & get_value () const
Return selected value.

• const std::vector< std::string > & get_entries () const
Return keyword list.

• const size_t & get_index () const
Return index of selected value.

• void validate () const
Check if index of selected value is valid.

• keyword_list_t ()
Constructor.

Private Attributes
• size_t index
Index into list.

• std::vector< std::string > entries
List of valid entries.

4.95.1

Detailed Description

The stucture keyword_list_t (p. 212) defines a keyword list (vector of strings) with an index into
the list. Used as MHAParser::kw_t (p. 214), it can be used to access a set of valid keywords
through the parser (i.e. one of "pear apple banana").

4.95.2
4.95.2.1

Member Function Documentation
void MHAParser::keyword_list_t::set_value ( const std::string & s )

This function selects a value from the keyword list. The index is set to the last matching entry.
Parameters
s

Value to be selected.

4.95.2.2

void MHAParser::keyword_list_t::set_entries ( const std::string & s )

With this function, the keyword list can be set from a space separated string list.
Parameters
s

Space separated entry list.

© 2005-2018 HörTech gGmbH, Oldenburg

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4.96

CONTENTS

MHAParser::kw_t Class Reference

Variable with keyword list value.
Inheritance diagram for MHAParser::kw_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::kw_t

MHAParser::commit_t
< receiver_t >

Public Member Functions
• kw_t (const std::string &, const std::string &, const std::string &)
Constructor of a keyword list openMHA configuration variable.

• kw_t (const kw_t &)
Copy constructor.

• void set_range (const std::string &)
Set/change the list of valid entries.

• bool isval (const std::string &) const
Test if the given value is selected.

Public Attributes
• keyword_list_t data
Variable data in its native type.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::mcomplex_mon_t Class Reference

4.96.1

215

Constructor & Destructor Documentation

4.96.1.1

MHAParser::kw_t::kw_t ( const std::string & h, const std::string & v, const std::string & rg )

Parameters
h

A help string describing the purpose of this variable.

v

The initial value, has to be a value from the list of possible values given in the last
parameter.

rg

A string containing the list of valid entries. The entries have to be separated by spaces.
The list of entries has to be delimited by brackets "[", "]".

4.96.2

Member Function Documentation

4.96.2.1

void MHAParser::kw_t::set_range ( const std::string & r )

Parameters
r

4.97

A string containing the list of valid entries. The entries have to be separated by spaces.
The list of entries has to be delimited by brackets "[", "]".

MHAParser::mcomplex_mon_t Class Reference

Matrix of complex numbers monitor.
Inheritance diagram for MHAParser::mcomplex_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::mcomplex
_mon_t

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CONTENTS

Public Member Functions
• mcomplex_mon_t (const std::string &hlp)
Create a matrix of complex floating point monitor values.

Public Attributes
• std::vector< std::vector< mha_complex_t > > data
Data field.

4.97.1

Constructor & Destructor Documentation

4.97.1.1

MHAParser::mcomplex_mon_t::mcomplex_mon_t ( const std::string & hlp )

Parameters
hlp

4.98

A help text describing this monitor variable.

MHAParser::mcomplex_t Class Reference

Matrix variable with complex value.
© 2005-2018 HörTech gGmbH, Oldenburg

4.99

MHAParser::mfloat_mon_t Class Reference

Inheritance diagram for MHAParser::mcomplex_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::mcomplex_t

Public Attributes

• std::vector< std::vector< mha_complex_t > > data
Data field.

Additional Inherited Members

4.99

MHAParser::mfloat_mon_t Class Reference

Matrix of floats monitor.
© 2005-2018 HörTech gGmbH, Oldenburg

217

218

CONTENTS

Inheritance diagram for MHAParser::mfloat_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::mfloat_mon_t

Public Member Functions
• mfloat_mon_t (const std::string &hlp)
Create a matrix of floating point monitor values.

Public Attributes
• std::vector< std::vector< float > > data
Data field.

4.99.1
4.99.1.1

Constructor & Destructor Documentation
MHAParser::mfloat_mon_t::mfloat_mon_t ( const std::string & hlp )

Parameters
hlp

4.100

A help text describing this monitor variable.

MHAParser::mfloat_t Class Reference

Matrix variable with float value.
© 2005-2018 HörTech gGmbH, Oldenburg

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MHAParser::mfloat_t Class Reference

219

Inheritance diagram for MHAParser::mfloat_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::mfloat_t

Public Member Functions
• mfloat_t (const std::string &, const std::string &, const std::string &="")
Create a float matrix parser variable.

Public Attributes
• std::vector< std::vector< float > > data
Data field.

Additional Inherited Members
4.100.1
4.100.1.1

Constructor & Destructor Documentation
MHAParser::mfloat_t::mfloat_t ( const std::string & h, const std::string & v, const std::string
& rg = "" )

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CONTENTS

Parameters
h

A human-readable text describing the purpose of this configuration variable.

v

The initial value of the variable, as a string, in openMHA configuration language: (e.g. "[[0
1]; [2 3]]" for a matrix), described in the "Multidimensional Variables" s2.1.3 section of the
openMHA User Manual.

rg

The numeric range to enforce on all members of the matrix.

4.101

MHAParser::mhapluginloader_t Class Reference

Class to create a plugin loader in a parser, including the load logic.

4.102

MHAParser::monitor_t Class Reference

Base class for monitors and variable nodes.
Inheritance diagram for MHAParser::monitor_t:

MHAParser::bool_mon_t

MHAParser::complex
_mon_t

MHAParser::float_mon_t

MHAParser::int_mon_t

MHAParser::commit_t
< receiver_t >

MHAParser::mcomplex
_mon_t

MHAParser::base_t

MHAParser::complex_t

MHAParser::mfloat_mon_t

MHAParser::bool_t

MHAParser::float_t

MHAParser::string_mon_t

MHAParser::kw_t

MHAParser::int_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::mcomplex_t

MHAParser::vcomplex
_mon_t

MHAParser::string_t

MHAParser::mfloat_t

MHAParser::vstring_t

MHAParser::vcomplex_t

MHAParser::monitor_t

MHAParser::vfloat_mon_t

MHAParser::vint_mon_t

MHAParser::vfloat_t

MHAParser::vint_t
MHAParser::vstring
_mon_t

Additional Inherited Members

4.103

MHAParser::parser_t Class Reference

Parser node class.
© 2005-2018 HörTech gGmbH, Oldenburg

4.103

MHAParser::parser_t Class Reference

221

Inheritance diagram for MHAParser::parser_t:

AuditoryProfile::parser_t

DynComp::dc_afterburn
_vars_t

DynComp::dc_afterburn_t

io_file_t

io_parser_t

io_tcp_parser_t
MHAParser::base_t

MHAParser::parser_t
MHAFilter::adapt_filter_t

MHAFilter::iir_filter_t

MHAIOJack::io_jack_t

MHAParser::window_t

MHAPlugin::plugin_t
< runtime_cfg_t >

Public Member Functions
• parser_t (const std::string &help_text="")
Construct detached node to be used in the configuration tree.

• void insert_item (const std::string &, base_t ∗)
Register a parser item into this sub-parser.

• void remove_item (const std::string &)
Remove an item by name.

• void force_remove_item (const std::string &)
Remove an item by name.

• void remove_item (const base_t ∗)
Remove an item by address.

Private Attributes
• std::string id_string
identification string

Additional Inherited Members
4.103.1

Detailed Description

A parser_t (p. 220) instance is a node in the configuration tree. A parser node can contain any
number of other parser_t (p. 220) instances or configuration language variables. These items
are inserted into a parser node using the parser_t::insert_item (p. 222) method.
© 2005-2018 HörTech gGmbH, Oldenburg

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4.103.2
4.103.2.1

CONTENTS

Constructor & Destructor Documentation
MHAParser::parser_t::parser_t ( const std::string & help_text = "" )

Parameters
help_text

4.103.3
4.103.3.1

A text describing this node. E.g. if this node lives at the root of some openMHA
plugin, then the help text should describe the functionality of the plugin.

Member Function Documentation
void MHAParser::parser_t::insert_item ( const std::string & n, MHAParser::base_t ∗ e )

This function registers an item under a given name into this sub-parser and makes it accessible
to the parser interface.
Parameters
n

Name of the item in the configuration tree

e

C++ pointer to the item instance. e can either point to a variable, to a monitor, or to
another sub-parser.

4.103.3.2

void MHAParser::parser_t::remove_item ( const std::string & n )

If the item does not exist, an error is being reported.
Parameters
n

Name of parser item to be removed from list.

4.103.3.3

void MHAParser::parser_t::force_remove_item ( const std::string & n )

Non-existing items are ignored.
Parameters
n

Name of parser item to be removed from list.

4.103.3.4

void MHAParser::parser_t::remove_item ( const base_t ∗ addr )

The item belonging to an address is being removed from the list of items.

© 2005-2018 HörTech gGmbH, Oldenburg

4.104

MHAParser::range_var_t Class Reference

223

Parameters
addr

4.104

Address of parser item to be removed.

MHAParser::range_var_t Class Reference

Base class for all variables with a numeric value range.
Inheritance diagram for MHAParser::range_var_t:

MHAParser::complex_t

MHAParser::float_t

MHAParser::int_t

MHAParser::mcomplex_t
MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t
MHAParser::mfloat_t

MHAParser::vcomplex_t

MHAParser::vfloat_t

MHAParser::vint_t

Public Member Functions
• void set_range (const std::string &r)
Change the valid range of a variable.

Protected Attributes
• float low_limit
Lower limit of range.

• float up_limit
Upper limit of range.

• bool low_incl
Lower limit is included (or excluded) in range.

• bool up_incl
Upper limit is included (or excluded) in range.

• bool check_low
Check lower limit.

• bool check_up
Check upper limit.

• bool check_range
Range checking is active.
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CONTENTS

Additional Inherited Members
4.104.1

Member Function Documentation

4.104.1.1

void MHAParser::range_var_t::set_range ( const std::string & r )

Parameters
r

New range of the variable (string representation)

4.105

MHAParser::string_mon_t Class Reference

Monitor with string value.
Inheritance diagram for MHAParser::string_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::string_mon_t

Public Member Functions
• string_mon_t (const std::string &hlp)
Create a monitor variable for string values.

Public Attributes
• std::string data
Data field.

4.105.1
4.105.1.1

Constructor & Destructor Documentation
MHAParser::string_mon_t::string_mon_t ( const std::string & hlp )

© 2005-2018 HörTech gGmbH, Oldenburg

4.106

MHAParser::string_t Class Reference

225

Parameters
hlp

4.106

A help text describing this monitor variable.

MHAParser::string_t Class Reference

Variable with a string value.
Inheritance diagram for MHAParser::string_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::string_t

Public Member Functions
• string_t (const std::string &, const std::string &)
Constructor of a openMHA configuration variable for string values.

Public Attributes
• std::string data
Data field.

4.106.1
4.106.1.1

Constructor & Destructor Documentation
MHAParser::string_t::string_t ( const std::string & h, const std::string & v )

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CONTENTS

Parameters
A help string describing the purpose of this variable.
The initial string value

h
v

4.107

MHAParser::variable_t Class Reference

Base class for variable nodes.
Inheritance diagram for MHAParser::variable_t:

MHAParser::commit_t
< receiver_t >

MHAParser::complex_t

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::bool_t

MHAParser::float_t

MHAParser::kw_t

MHAParser::int_t

MHAParser::range_var_t

MHAParser::mcomplex_t

MHAParser::string_t

MHAParser::mfloat_t

MHAParser::vstring_t

MHAParser::vcomplex_t

MHAParser::vfloat_t

MHAParser::vint_t

Public Member Functions
• void setlock (const bool &)
Lock a variable against write access.

Additional Inherited Members
4.107.1

Member Function Documentation

4.107.1.1

void MHAParser::variable_t::setlock ( const bool & b )

Parameters
b

4.108

Lock state

MHAParser::vcomplex_mon_t Class Reference

Monitor with vector of complex values.
© 2005-2018 HörTech gGmbH, Oldenburg

4.109

MHAParser::vcomplex_t Class Reference

227

Inheritance diagram for MHAParser::vcomplex_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::vcomplex
_mon_t

Public Member Functions
• vcomplex_mon_t (const std::string &hlp)
Create a vector of complex monitor values.

Public Attributes
• std::vector< mha_complex_t > data
Data field.

4.108.1

Constructor & Destructor Documentation

4.108.1.1

MHAParser::vcomplex_mon_t::vcomplex_mon_t ( const std::string & hlp )

Parameters
hlp

4.109

A help text describing this monitor variable.

MHAParser::vcomplex_t Class Reference

Vector variable with complex value.
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CONTENTS

Inheritance diagram for MHAParser::vcomplex_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::vcomplex_t

Public Attributes

• std::vector< mha_complex_t > data
Data field.

Additional Inherited Members

4.110

MHAParser::vfloat_mon_t Class Reference

Vector of floats monitor.
© 2005-2018 HörTech gGmbH, Oldenburg

4.111

MHAParser::vfloat_t Class Reference

Inheritance diagram for MHAParser::vfloat_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::vfloat_mon_t

Public Member Functions
• vfloat_mon_t (const std::string &hlp)
Create a vector of floating point monitor values.

Public Attributes
• std::vector< float > data
Data field.

4.110.1

Constructor & Destructor Documentation

4.110.1.1

MHAParser::vfloat_mon_t::vfloat_mon_t ( const std::string & hlp )

Parameters
hlp

4.111

A help text describing this monitor variable.

MHAParser::vfloat_t Class Reference

Vector variable with float value.
© 2005-2018 HörTech gGmbH, Oldenburg

229

230

CONTENTS

Inheritance diagram for MHAParser::vfloat_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::vfloat_t

Public Member Functions
• vfloat_t (const std::string &, const std::string &, const std::string &="")
Create a float vector parser variable.

Public Attributes
• std::vector< float > data
Data field.

Additional Inherited Members
4.111.1
4.111.1.1

Constructor & Destructor Documentation
MHAParser::vfloat_t::vfloat_t ( const std::string & h, const std::string & v, const std::string &
rg = "" )

© 2005-2018 HörTech gGmbH, Oldenburg

4.112

MHAParser::vint_mon_t Class Reference

231

Parameters
h

A human-readable text describing the purpose of this configuration variable.

v

The initial value of the variable, as a string, in openMHA configuration language:
(e.g. "[0 1 2.1 3]" for a vector), described in the "Multidimensional Variables"
s2.1.3 section of the openMHA User Manual.

rg

The numeric range to enforce on all members of the vector.
•

4.112

MHAParser::vint_mon_t Class Reference

Vector of ints monitor.
Inheritance diagram for MHAParser::vint_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::vint_mon_t

Public Member Functions
• vint_mon_t (const std::string &hlp)
Create a vector of integer monitor values.

Public Attributes
• std::vector< int > data
Data field.

4.112.1
4.112.1.1

Constructor & Destructor Documentation
MHAParser::vint_mon_t::vint_mon_t ( const std::string & hlp )

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CONTENTS

Parameters
hlp

4.113

A help text describing this monitor variable.

MHAParser::vint_t Class Reference

Variable with vector value.
Inheritance diagram for MHAParser::vint_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::range_var_t

MHAParser::vint_t

Public Member Functions
• vint_t (const std::string &, const std::string &, const std::string &="")
Constructor.

Public Attributes
• std::vector< int > data
Data field.
© 2005-2018 HörTech gGmbH, Oldenburg

4.114

MHAParser::vstring_mon_t Class Reference

233

Additional Inherited Members
4.113.1

Constructor & Destructor Documentation

4.113.1.1

MHAParser::vint_t::vint_t ( const std::string & h, const std::string & v, const std::string & rg =
"" )

Parameters
help string
initial value
optional: range constraint for all elements

h
v
rg

4.114

MHAParser::vstring_mon_t Class Reference

Vector of monitors with string value.
Inheritance diagram for MHAParser::vstring_mon_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::vstring
_mon_t

Public Member Functions
• vstring_mon_t (const std::string &hlp)
Create a vector of string monitor values.

Public Attributes
• std::vector< std::string > data
Data field.
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4.114.1

CONTENTS

Constructor & Destructor Documentation

4.114.1.1

MHAParser::vstring_mon_t::vstring_mon_t ( const std::string & hlp )

Parameters
hlp

4.115

A help text describing this monitor variable.

MHAParser::vstring_t Class Reference

Vector variable with string values.
Inheritance diagram for MHAParser::vstring_t:

MHAParser::base_t

MHAParser::monitor_t

MHAParser::variable_t

MHAParser::vstring_t

Public Attributes
• std::vector< std::string > data
Data field.

Additional Inherited Members

4.116

MHAParser::window_t Class Reference

MHA configuration interface for a window function generator.
© 2005-2018 HörTech gGmbH, Oldenburg

4.116

MHAParser::window_t Class Reference

235

Inheritance diagram for MHAParser::window_t:

MHAParser::base_t

MHAParser::parser_t

MHAParser::window_t

Public Member Functions
• window_t (const std::string &help="Window type configuration.")
Constructor to create parser class.

• MHAWindow::base_t get_window (unsigned int len) const
Create a window instance, use default parameters.

• MHAWindow::base_t get_window (unsigned int len, float xmin) const
Create a window instance.

• MHAWindow::base_t get_window (unsigned int len, float xmin, float xmax) const
Create a window instance.

• MHAWindow::base_t get_window (unsigned int len, float xmin, float xmax, bool minincluded) const
Create a window instance.

• MHAWindow::base_t get_window (unsigned int len, float xmin, float xmax, bool minincluded, bool maxincluded) const
Create a window instance.

• MHAParser::window_t::wtype_t get_type () const
Return currently selected window type.

Additional Inherited Members
4.116.1

Detailed Description

This class implements a configuration interface (sub-parser) for window type selection and
user-defined window type. It provides member functions to generate an instance of MHA←Window::base_t (p. 278) based on the values provided by the configuration interface.
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CONTENTS

The configuration interface is derived from MHAParser::parser_t (p. 220) and can thus be
inserted into the configuration tree using the insert_item() (p. 222) method of the parent parser.
If one of the pre-defined window types is used, then the window is generated using the MHA←Window::fun_t (p. 280) class constructor; for the user-defined type the values from the "user"
variable are copied.

4.117

MHAPlugin::config_t< runtime_cfg_t > Class Template Reference

Template class for thread safe configuration.
Inheritance diagram for MHAPlugin::config_t< runtime_cfg_t >:

MHAPlugin::config_t
< runtime_cfg_t >

MHAPlugin::plugin_t
< runtime_cfg_t >

Protected Member Functions
• runtime_cfg_t ∗ poll_config ()
Receive the latest run time configuration.

• runtime_cfg_t ∗ last_config ()
Receive the latest run time configuration.

• void push_config (runtime_cfg_t ∗ncfg)
Push a new run time configuration into the configuration fifo.

4.117.1

Detailed Description

template
class MHAPlugin::config_t< runtime_cfg_t >
This template class provides a mechanism for the handling of thread safe configuration which
is required for run time configuration changes of the openMHA plugins.
© 2005-2018 HörTech gGmbH, Oldenburg

4.117 MHAPlugin::config_t< runtime_cfg_t > Class Template
Reference

237

The template parameter runtime_cfg_t is the run time configuration class of the openMHA
plugin. The constructor of that class should transform the MHAParser (p. 76) variables into
derived runtime configuration. The constructor should fail if the configuration is invalid by any
reason.
A new runtime configuration is provided by the function push_config() (p. 238). In the processing thread, the actual configuration can be received by a call of poll_config() (p. 237).

in_use

next

configuration

in_use

next

configuration

current configuration
Figure 5 Schematic drawing of runtime configuration update: configuration updated,
but not used yet.

in_use

next

configuration

in_use

next

configuration

current configuration
Figure 6 Schematic drawing of runtime configuration update: configuration in use.

4.117.2
4.117.2.1

Member Function Documentation
template runtime_cfg_t ∗ MHAPlugin::config_t< runtime_cfg_t
>::poll_config ( ) [protected]

This function stores the latest run time configuration into the protected class member variable
‘cfg'. If no configuration exists, then an exception will be thrown. If no changes occured, then
the value of ‘cfg' will be untouched. This function should be called before any access to the
‘cfg' variable, typically once in each signal processing call.
This function should be only called from the processing thread.

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CONTENTS

Exceptions
MHA_Error ( p. 132)

4.117.2.2

if the resulting runtime configuration is NULL. This usually means
that no push_config has occured.

template runtime_cfg_t ∗ MHAPlugin::config_t< runtime_cfg_t
>::last_config ( ) [protected]

This function stores the latest run time configuration into the protected class member variable
‘cfg'. If no configuration exists, then an exception will be thrown. If no changes occured, then
the value of ‘cfg' will be untouched. This function may be called instead of poll_config.
The difference between poll_config and last_config is that poll_config marks previous configurations as ready for deletion, while this function does not. Therefore, memory usage of all
runtime configurations will accumulate if only this function is called, but it enables safe access
to previous runtime configurations.
Also, last_config does not raise an Exception when the latest run time configuration is NULL.
4.117.2.3

template void MHAPlugin::config_t< runtime_cfg_t
>::push_config ( runtime_cfg_t ∗ ncfg ) [protected]

This function adds a new run time configuration. The next time poll_config (p. 237) is called,
this configuration will be available. Configurations which are not in use or are outdated will be
removed.
This function should be only called from the configuration thread.
Parameters
ncfg

pointer on a new configuration

Warning
The runtime configuration passed to this function will be removed by the internal garbage
collector. Do not free manually.

4.118

MHAPlugin::plugin_t< runtime_cfg_t > Class Template Reference

The template class for C++ openMHA plugins.
© 2005-2018 HörTech gGmbH, Oldenburg

4.118 MHAPlugin::plugin_t< runtime_cfg_t > Class Template
Reference

239

Inheritance diagram for MHAPlugin::plugin_t< runtime_cfg_t >:

MHAParser::base_t

MHAParser::parser_t

MHAPlugin::config_t
< runtime_cfg_t >

MHAPlugin::plugin_t
< runtime_cfg_t >

Public Member Functions
• plugin_t (const std::string &, const algo_comm_t &)
Constructor of plugin template.

• bool is_prepared () const
Flag, if the prepare method is successfully called (or currently evaluated)

• mhaconfig_t input_cfg () const
Current input channel configuration.

• mhaconfig_t output_cfg () const
Current output channel configuration.

Protected Attributes
• mhaconfig_t tftype
Member for storage of plugin interface configuration.

• algo_comm_t ac
AC handle of the chain.

Additional Inherited Members
4.118.1

Detailed Description

template
class MHAPlugin::plugin_t< runtime_cfg_t >

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CONTENTS

Template Parameters
runtime_←cfg_t

run-time configuration.

This template class provides thread safe configuration handling and standard methods to be
compatible to the C++ openMHA plugin wrapper macro MHAPLUGIN_CALLBACKS (p. 8).
The template parameter runtime_cfg_t should be the runtime configuration of the plugin.
See MHAPlugin::config_t (p. 236) for details on the thread safe communication update mechanism.

4.118.2
4.118.2.1

Constructor & Destructor Documentation
template MHAPlugin::plugin_t< runtime_cfg_t >::plugin_t (
const std::string & help, const algo_comm_t & iac )

Parameters
help

Help comment to provide some general information about the plugin.

iac

AC space handle (will be stored into the member variable ac).

4.118.3

4.118.3.1

Member Data Documentation

template mhaconfig_t MHAPlugin::plugin_t< runtime_cfg_t
>::tftype [protected]

This member is defined for convenience of the developer. Typically, the actual contents of
mhaconfig_t (p. 155) are stored in this member in the prepare() method.

Note
This member is likely to be removed in later versions, use input_cfg() (p. 239) and
output_cfg() (p. 239) instead.

4.118.3.2

template algo_comm_t MHAPlugin::plugin_t< runtime_cfg_t
>::ac [protected]

This variable is initialized in the constructor and can be used by derived plugins to access the
AC space. Its contents should not be modified.
© 2005-2018 HörTech gGmbH, Oldenburg

4.119

mhaserver_t Class Reference

4.119

mhaserver_t Class Reference

241

MHA Framework listening on TCP port for commands.
Inherits fw_t.

Public Member Functions
• mhaserver_t (const std::string &ao, const std::string &af, const std::string &lf)
• virtual std::string received_group (const std::string &line)
A line of text was received from network client.

• virtual void acceptor_started (int status)
Notification: "TCP port is open".

• virtual void set_announce_port (unsigned short announce_port)
If set to nonzero, the spawning process has asked to be notified of the TCP port used by this
process.

• void logstring (const std::string &)
Log a message to log file.

• int run (unsigned short port, const std::string &_interface)
Accept network connections and act on commands.

4.119.1

Constructor & Destructor Documentation

4.119.1.1

mhaserver_t::mhaserver_t ( const std::string & ao, const std::string & af, const std::string &
lf )

Parameters
ao

Acknowledgement string at end of successful command responses

af

Achknoledgement string at end of failed command responses

lf

File system path of file to use as log file. MHA appends.

4.119.2

Member Function Documentation

4.119.2.1

void mhaserver_t::set_announce_port ( unsigned short announce_port ) [virtual]

4.119.2.2

int mhaserver_t::run ( unsigned short port, const std::string & _interface )

Calls acceptor_started() (p. 241) when the TCP port is opened. Calls received_group for every
line received.
Returns
exit code that can be used as process exit code
© 2005-2018 HörTech gGmbH, Oldenburg

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4.120

CONTENTS

MHASignal::async_rmslevel_t Class Reference

Class for asynchronous level metering.
Inheritance diagram for MHASignal::async_rmslevel_t:

mha_wave_t

MHASignal::waveform_t

MHASignal::async_rmslevel_t

Public Member Functions
• async_rmslevel_t (unsigned int frames, unsigned int channels)
Constructor for level metering class.

• std::vector< float > rmslevel () const
Read-only function for querying the current RMS level.

• std::vector< float > peaklevel () const
Read-only function for querying the current peak level.

• void process (mha_wave_t ∗s)
Function to store a chunk of audio in the level meter.

Additional Inherited Members
4.120.1

Detailed Description

4.120.2

Constructor & Destructor Documentation

4.120.2.1

MHASignal::async_rmslevel_t::async_rmslevel_t ( unsigned int frames, unsigned int channels
)

Allocate memory for metering. The RMS integration time corresponds to the number of frames
in the buffer.

© 2005-2018 HörTech gGmbH, Oldenburg

4.121

MHASignal::delay_t Class Reference

243

Parameters
frames

Number of frames to integrate.

channels

Number of channels used for level-metering.

4.120.3

Member Function Documentation

4.120.3.1

std::vector< float > MHASignal::async_rmslevel_t::rmslevel ( ) const

Returns
Vector of floats, one value for each channel, containing the RMS level in dB (SPL if calibrated properly).

4.120.3.2

std::vector< float > MHASignal::async_rmslevel_t::peaklevel ( ) const

Returns
Vector of floats, one value for each channel, containing the peak level in dB (SPL if calibrated properly).

4.120.3.3

void MHASignal::async_rmslevel_t::process ( mha_wave_t ∗ s )

Parameters
s

Audio chunk (same number of channels required as given in the constructor).

4.121

MHASignal::delay_t Class Reference

Class to realize a simple delay of waveform streams.

Public Member Functions
• delay_t (std::vector< int > delays, unsigned int channels)
Constructor.

• mha_wave_t ∗ process (mha_wave_t ∗s)
Processing method.

4.121.1
4.121.1.1

Constructor & Destructor Documentation
MHASignal::delay_t::delay_t ( std::vector< int > delays, unsigned int channels )

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CONTENTS

Parameters
delays

Vector of delays, one entry for each channel.

channels

Number of channels expected.

4.121.2

Member Function Documentation

4.121.2.1 mha_wave_t ∗ MHASignal::delay_t::process ( mha_wave_t ∗ s )
Parameters
s

Input waveform fragment, with number of channels provided in constructor.

Returns
Output waveform fragment.

4.122

MHASignal::delay_wave_t Class Reference

Delayline containing wave fragments.

4.122.1

Detailed Description

The delayline contains waveform fragments. The delay can be configured in integer fragments
(sample delay or sub-sample delay is not possible).

4.123

MHASignal::doublebuffer_t Class Reference

Double-buffering class.

Public Member Functions
• doublebuffer_t (unsigned int nchannels_in, unsigned int nchannels_out, unsigned int
outer_fragsize, unsigned int inner_fragsize)
Constructor of double buffer.

• mha_wave_t ∗ outer_process (mha_wave_t ∗s)
Method to pass audio fragments into the inner layer.

Protected Member Functions
• virtual mha_wave_t ∗ inner_process (mha_wave_t ∗s)=0
Method to realize inner processing callback.
© 2005-2018 HörTech gGmbH, Oldenburg

4.123

MHASignal::doublebuffer_t Class Reference

4.123.1

Detailed Description

245

This class has two layers: The outer layer, with an outer fragment size, and an inner layer,
with its own fragment size. Data is passed into the inner layer through the doublebuffer_t←::outr_process() callback. The pure virtual method doublebuffer_t::inner_process() (p. 245)
is called whenever enough data is available.

4.123.2
4.123.2.1

Constructor & Destructor Documentation
MHASignal::doublebuffer_t::doublebuffer_t ( unsigned int nchannels_in, unsigned int
nchannels_out, unsigned int outer_fragsize, unsigned int inner_fragsize )

Parameters
nchannels_in

Number of channels at the input (both layers).

nchannels_out

Number of channels at the output (both layers).

outer_fragsize

Fragment size of the outer layer (e.g., hardware fragment size)

inner_fragsize

Fragment size of the inner layer (e.g., software fragment size)

4.123.3

Member Function Documentation

4.123.3.1 mha_wave_t ∗ MHASignal::doublebuffer_t::outer_process ( mha_wave_t ∗ s )
Parameters
s

Pointer to input waveform fragment.

Returns
Pointer to output waveform fragment.

4.123.3.2

virtual mha_wave_t∗ MHASignal::doublebuffer_t::inner_process ( mha_wave_t ∗ s )
[protected], [pure virtual]

To be overwritten by derived classes.
Parameters
s

Pointer to input waveform fragment.

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CONTENTS

Returns
Pointer to output waveform fragment.

4.124

MHASignal::hilbert_t Class Reference

Hilbert transformation of a waveform segment.
Inheritance diagram for MHASignal::hilbert_t:

MHASignal::hilbert_t

MHASignal::minphase_t

Public Member Functions
• hilbert_t (unsigned int len)
• void operator() (const mha_wave_t ∗, mha_wave_t ∗)
Apply Hilbert transformation on a waveform segment.

4.124.1

Detailed Description

Returns the imaginary part of the inverse Fourier transformation of the Fourier transformed
input signal with negative frequencies set to zero.

4.124.2

Constructor & Destructor Documentation

4.124.2.1

MHASignal::hilbert_t::hilbert_t ( unsigned int len )

Parameters
len

Length of waveform segment

© 2005-2018 HörTech gGmbH, Oldenburg

4.125

MHASignal::loop_wavefragment_t Class Reference

4.125

MHASignal::loop_wavefragment_t Class Reference

247

Copy a fixed waveform fragment to a series of waveform fragments of other size.
Inheritance diagram for MHASignal::loop_wavefragment_t:

mha_wave_t

MHASignal::waveform_t

MHASignal::loop_wavefragment_t

Public Types
Public Member Functions
• loop_wavefragment_t (const mha_wave_t &src, bool loop, level_mode_t level_mode,
std::vector< int > channels, unsigned int startpos=0)
Constructor to create an instance of loop_wavefragment_t ( p. 247) based on an existing
waveform block.

• void playback (mha_wave_t ∗s, playback_mode_t pmode, mha_wave_t ∗level_pa,
const std::vector< int > &channels)
Add source waveform block to an output block.

• void playback (mha_wave_t ∗s, playback_mode_t pmode, mha_wave_t ∗level_pa)
Add source waveform block to an output block.

• void playback (mha_wave_t ∗s, playback_mode_t pmode)
Add source waveform block to an output block.

Additional Inherited Members
4.125.1

Detailed Description

This class is designed to continously play back a waveform to an output stream, with variable
output block size.
© 2005-2018 HörTech gGmbH, Oldenburg

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4.125.2

CONTENTS

Member Enumeration Documentation

4.125.2.1

enum MHASignal::loop_wavefragment_t::level_mode_t

Enumerator
relative The nominal level is applied as a gain to the source signal.
peak The nominal level is the peak level of source signal in Pascal.
rms The nominal level is the RMS level of the source signal in Pascal.

4.125.2.2

enum MHASignal::loop_wavefragment_t::playback_mode_t

Enumerator
add Add source signal to output stream.
replace Replace output stream by source signal.
input Do nothing, keep output stream (source position is unchanged).
mute Mute output stream (source position is unchanged).

4.125.3

Constructor & Destructor Documentation

4.125.3.1

MHASignal::loop_wavefragment_t::loop_wavefragment_t ( const mha_wave_t & src, bool
loop, level_mode_t level_mode, std::vector< int > channels, unsigned int startpos = 0 )

Parameters
src
loop

Waveform block to copy data from.
Flag whether the block should be looped or played once.

level_mode

Configuration of playback level (see
MHASignal::loop_wavefragment_t::level_mode_t (p. 248) for details)

channels

Mapping of input to output channels.

startpos

Starting position

4.125.4

Member Function Documentation

4.125.4.1

void MHASignal::loop_wavefragment_t::playback ( mha_wave_t ∗ s, playback_mode_t
pmode, mha_wave_t ∗ level_pa, const std::vector< int > & channels )

Parameters
s

Output block (streamed signal).

pmode

Playback mode (add, replace, input, mute).

level_pa

Linear output level/gain (depending on level_mode parameter in constructor);
one value for each sample in output block.
© 2005-2018 HörTech gGmbH, Oldenburg

4.126

MHASignal::matrix_t Class Reference

249

Parameters
channels

4.125.4.2

Output channels

void MHASignal::loop_wavefragment_t::playback ( mha_wave_t ∗ s, playback_mode_t
pmode, mha_wave_t ∗ level_pa )

Parameters
s

Output block (streamed signal).

pmode

Playback mode (add, replace, input, mute).

level_pa

Linear output level/gain (depending on level_mode parameter in constructor);
one value for each sample in output block.

4.125.4.3

void MHASignal::loop_wavefragment_t::playback ( mha_wave_t ∗ s, playback_mode_t
pmode )

Parameters
s

Output block (streamed signal).

pmode

Playback mode (add, replace, input, mute).

4.126

MHASignal::matrix_t Class Reference

n-dimensional matrix with real or complex floating point values.
Inheritance diagram for MHASignal::matrix_t:

MHASignal::uint_vector_t

MHASignal::matrix_t

MHA_AC::ac2matrix_t

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CONTENTS

Public Member Functions
• matrix_t (unsigned int nrows, unsigned int ncols, bool b_is_complex=true)
Create a two-dimensional matrix.

• matrix_t (const mha_spec_t &spec)
Create a two-dimensional matrix from a spectrum, copy values.

• matrix_t (const MHASignal::uint_vector_t &size, bool b_is_complex=true)
Create n-dimensional matrix, descriped by size argument.

• matrix_t (const uint8_t ∗buf, unsigned int len)
Construct from memory area.

• MHASignal::matrix_t & operator= (const comm_var_t &v)
Fill matrix with data of an AC variable object.

• comm_var_t get_comm_var ()
Return a AC communication variable pointing to the data of the current matrix.

• unsigned int dimension () const
Return the dimension of the matrix.

• unsigned int size (unsigned int k) const
Return the size of the matrix.

• unsigned int get_nelements () const
Return total number of elements.

• bool is_same_size (const MHASignal::matrix_t &)
Test if matrix has same size as other.

• bool iscomplex () const
Return information about complexity.

• mha_real_t & real (const MHASignal::uint_vector_t &index)
Access real part of an element in a n-dimensional matrix.

• mha_real_t & imag (const MHASignal::uint_vector_t &index)
Access imaginary part of an element in a n-dimensional matrix.

• mha_complex_t & operator() (const MHASignal::uint_vector_t &index)
Access complex value of an element in a n-dimensional matrix.

• const mha_real_t & real (const MHASignal::uint_vector_t &index) const
Access real part of an element in a n-dimensional matrix.

• const mha_real_t & imag (const MHASignal::uint_vector_t &index) const
Access imaginary part of an element in a n-dimensional matrix.

• const mha_complex_t & operator() (const MHASignal::uint_vector_t &index) const
Access complex value of an element in a n-dimensional matrix.

• mha_real_t & real (unsigned int row, unsigned int col)
Access real part of an element in a two-dimensional matrix.

• mha_real_t & imag (unsigned int row, unsigned int col)
Access imaginary part of an element in a two-dimensional matrix.

• mha_complex_t & operator() (unsigned int row, unsigned int col)
Access complex value of an element in a two-dimensional matrix.

• const mha_real_t & real (unsigned int row, unsigned int col) const
Access real part of an element in a two-dimensional matrix.

• const mha_real_t & imag (unsigned int row, unsigned int col) const
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MHASignal::matrix_t Class Reference

251

Access imaginary part of an element in a two-dimensional matrix.

• const mha_complex_t & operator() (unsigned int row, unsigned int col) const
Access complex value of an element in a two-dimensional matrix.

• unsigned int numbytes () const
Return number of bytes needed to store into memory.

• unsigned int write (uint8_t ∗buf, unsigned int len) const
Copy to memory area.

• const mha_real_t ∗ get_rdata () const
Return pointer of real data.

• const mha_complex_t ∗ get_cdata () const
Return pointer of complex data.

Additional Inherited Members
4.126.1

Detailed Description

Warning
The member functions imag() (p. 253) and operator() should only be called if the matrix
is defined to hold complex values.

4.126.2
4.126.2.1

Constructor & Destructor Documentation
MHASignal::matrix_t::matrix_t ( unsigned int nrows, unsigned int ncols, bool b_is_complex =
true )

Parameters
nrows
ncols
b_is_complex

4.126.2.2

Number of rows
Number of columns
Add space for complex values

MHASignal::matrix_t::matrix_t ( const mha_spec_t & spec )

Parameters
spec

4.126.2.3

Source spectrum structure

MHASignal::matrix_t::matrix_t ( const MHASignal::uint_vector_t & size, bool
b_is_complex = true )

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CONTENTS

Parameters
size
b_is_complex

4.126.2.4

Size vector
Add space for complex values

MHASignal::matrix_t::matrix_t ( const uint8_t ∗ buf, unsigned int len )

Warning
This constructor is not real time safe

4.126.3

Member Function Documentation

4.126.3.1 MHASignal::matrix_t & MHASignal::matrix_t::operator= ( const comm_var_t & v )
Parameters
v

Source AC variable (comm_var_t (p. 95))

Note
The type and dimension of the AC variable must match the type and dimension of the
matrix.

4.126.3.2 comm_var_t MHASignal::matrix_t::get_comm_var ( )
Returns
AC variable object (comm_var_t (p. 95)), valid for the life time of the matrix.

4.126.3.3

unsigned int MHASignal::matrix_t::dimension ( ) const [inline]

Returns
Dimension of the matrix

4.126.3.4

unsigned int MHASignal::matrix_t::size ( unsigned int k ) const [inline]

Parameters
k

Dimension

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MHASignal::matrix_t Class Reference

253

Returns
Size of the matrix in dimension k

4.126.3.5 mha_real_t& MHASignal::matrix_t::real ( const MHASignal::uint_vector_t & index )
[inline]
Parameters
index

Index vector

4.126.3.6 mha_real_t& MHASignal::matrix_t::imag ( const MHASignal::uint_vector_t & index )
[inline]
Parameters
index

Index vector

4.126.3.7 mha_complex_t& MHASignal::matrix_t::operator() ( const MHASignal::uint_vector_t
& index ) [inline]
Parameters
index

4.126.3.8

Index vector

const mha_real_t& MHASignal::matrix_t::real ( const MHASignal::uint_vector_t &
index ) const [inline]

Parameters
index

4.126.3.9

Index vector

const mha_real_t& MHASignal::matrix_t::imag ( const MHASignal::uint_vector_t &
index ) const [inline]

Parameters
index

4.126.3.10

Index vector

const mha_complex_t& MHASignal::matrix_t::operator() ( const
MHASignal::uint_vector_t & index ) const [inline]

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Parameters
Index vector

index

4.126.3.11 mha_real_t& MHASignal::matrix_t::real ( unsigned int row, unsigned int col ) [inline]
Parameters
row
col

Row number of element
Column number of element

4.126.3.12 mha_real_t& MHASignal::matrix_t::imag ( unsigned int row, unsigned int col )
[inline]
Parameters
row
col

Row number of element
Column number of element

4.126.3.13 mha_complex_t& MHASignal::matrix_t::operator() ( unsigned int row, unsigned int col )
[inline]
Parameters
row
col

Row number of element
Column number of element

4.126.3.14

const mha_real_t& MHASignal::matrix_t::real ( unsigned int row, unsigned int col ) const
[inline]

Parameters
row
col

Row number of element
Column number of element

4.126.3.15

const mha_real_t& MHASignal::matrix_t::imag ( unsigned int row, unsigned int col ) const
[inline]

Parameters
row
col

Row number of element
Column number of element

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4.127

MHASignal::minphase_t Class Reference

4.126.3.16

255

const mha_complex_t& MHASignal::matrix_t::operator() ( unsigned int row, unsigned int
col ) const [inline]

Parameters
row
col

4.127

Row number of element
Column number of element

MHASignal::minphase_t Class Reference

Minimal phase function.
Inheritance diagram for MHASignal::minphase_t:

MHASignal::hilbert_t

MHASignal::minphase_t

Public Member Functions
• minphase_t (unsigned int fftlen, unsigned int ch)
Constructor.

• void operator() (mha_spec_t ∗s)
Transform input spectrum to a minimal-phase spectrum, discarding the original phase.

Additional Inherited Members
4.127.1

Detailed Description

The output spectrum Y (f ) is

Y (f ) = |X(f )|eiH{log |X(f )|} ,

with the input spectrum X(f ) and the Hilbert transformation H{· · ·}.

4.127.2
4.127.2.1

Constructor & Destructor Documentation
MHASignal::minphase_t::minphase_t ( unsigned int fftlen, unsigned int ch )

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CONTENTS

Parameters
fftlen

FFT length

ch

Number of channels

4.127.3

Member Function Documentation

4.127.3.1

void MHASignal::minphase_t::operator() ( mha_spec_t ∗ s )

Parameters
s

Spectrum to operate on.

4.128

MHASignal::quantizer_t Class Reference

Simple simulation of fixpoint quantization.

Public Member Functions
• quantizer_t (unsigned int num_bits)
Constructor.

• void operator() (mha_wave_t &s)
Quantization of a waveform fragment.

4.128.1

Detailed Description

4.128.2

Constructor & Destructor Documentation

4.128.2.1

MHASignal::quantizer_t::quantizer_t ( unsigned int num_bits )

Parameters
num_bits

4.128.3
4.128.3.1

Number of bits to simulate, or zero for limiting to [-1,1] only.

Member Function Documentation
void MHASignal::quantizer_t::operator() ( mha_wave_t & s )

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MHASignal::ringbuffer_t Class Reference

257

Parameters
s

Waveform fragment to be quantized.

4.129

MHASignal::ringbuffer_t Class Reference

A ringbuffer class for time domain audio signal, which makes no assumptions with respect to
fragment size.
Inheritance diagram for MHASignal::ringbuffer_t:

mha_wave_t

MHASignal::waveform_t

MHASignal::ringbuffer_t

Public Member Functions
• ringbuffer_t (unsigned frames, unsigned channels, unsigned prefilled_frames)
Creates new ringbuffer.

• unsigned contained_frames () const
number of currently contained frames

• mha_real_t & value (unsigned frame, unsigned channel)
Access to value stored in ringbuffer.

• void discard (unsigned frames)
Discards the oldest frames Makes room for new write ( p. 259), alters base frame index for
value ( p. 258).

• void write (mha_wave_t &signal)
Copies the contents of the signal into the ringbuffer if there is space.

Private Attributes
• unsigned next_read_frame_index
identifies place with oldest frame in ringbuffer

• unsigned next_write_frame_index
identifies place to store next frame in ringbuffer
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Additional Inherited Members
4.129.1

Detailed Description

4.129.2

Constructor & Destructor Documentation

4.129.2.1

ringbuffer_t::ringbuffer_t ( unsigned frames, unsigned channels, unsigned prefilled_frames )

Parameters
frames

Size of ringbuffer. Maximum frames can be stored in ringbuffer.

channels
prefilled_frames

Number of audio channels.
Number of frames to be prefilled with zero values

Exceptions
MHA_Error ( p. 132)

4.129.3

if prefilled_frames > frames

Member Function Documentation

4.129.3.1 mha_real_t& MHASignal::ringbuffer_t::value ( unsigned frame, unsigned channel )
[inline]
Parameters
frame index, 0 corresponds to oldest frame stored.
audio channel

frame
channel

Returns
reference to contained sample value
Exceptions
MHA_Error ( p. 132)

4.129.3.2

if channel or frame out of bounds.

void MHASignal::ringbuffer_t::discard ( unsigned frames ) [inline]

Parameters
frames

how many frames to discard.

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MHASignal::schroeder_t Class Reference

259

Exceptions
MHA_Error ( p. 132)

4.129.3.3

if frames > contained_frames (p. 257)

void MHASignal::ringbuffer_t::write ( mha_wave_t & signal ) [inline]

Parameters
signal

New signal to be appended to the signal already present in the ringbuffer

Exceptions
MHA_Error ( p. 132)

4.130

if there is not enough space or if the channel count mismatches.

MHASignal::schroeder_t Class Reference

Schroeder tone complex class.
Inheritance diagram for MHASignal::schroeder_t:

mha_wave_t

MHASignal::waveform_t

MHASignal::schroeder_t

Public Types
• typedef float(∗ groupdelay_t) (float f, float fmin, float fmax)
Function type for group delay definition.
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CONTENTS

Public Member Functions
• schroeder_t (unsigned int len, unsigned int channels=1, schroeder_t::sign_t sign=up,
mha_real_t speed=1)
Constructor.

• schroeder_t (unsigned int len, unsigned int channels=1, schroeder_t::groupdelay_t
freqfun=MHASignal::schroeder_t::identity, float fmin=0, float fmax=1, float eps=1e-10)
Construct create Schroeder tone complex from a given frequency function.

Additional Inherited Members
4.130.1

Detailed Description

The Schroeder tone complex is a sweep defined in the sampled spectrum:

Φ(f ) = σ2πτ (2f /fs )2α ,

S(f ) = eiΦ(f )

f is the sampled frequency in Hz, σ is the sign of the sweep (-1 for up sweep, +1 for down
sweep), τ is the sweep duration in samples, fs is the sampling rate in Hz and α is the relative
sweep speed.

4.130.2
4.130.2.1

Member Typedef Documentation
typedef float(∗ MHASignal::schroeder_t::groupdelay_t) (float f, float fmin, float fmax)

Parameters
f

Frequency relative to Nyquist frequency.

fmin

Minimum frequency relative to Nyquist frequency.

fmax

Maximum frequency relative to Nyquist frequency.

4.130.3

4.130.3.1

Member Enumeration Documentation

enum MHASignal::schroeder_t::sign_t

Enumerator
up Sweep from zero to Nyquist frequency ( σ = −1)
down Sweep from Nyquist frequency to zero ( σ = +1)
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4.131

MHASignal::spectrum_t Class Reference

4.130.4

Constructor & Destructor Documentation

4.130.4.1

261

MHASignal::schroeder_t::schroeder_t ( unsigned int len, unsigned int channels = 1,
schroeder_t::sign_t sign = up, mha_real_t speed = 1 )

Parameters of the Schroeder tone complex are configured in the constructor.
Parameters
len

Length τ of the Schroeder tone complex in samples

channels
sign

Number of channels
Sign σ of Schroeder sweep

speed

Relative speed α (curvature of phase function)

4.130.4.2

MHASignal::schroeder_t::schroeder_t ( unsigned int len, unsigned int channels = 1,
schroeder_t::groupdelay_t freqfun = MHASignal::schroeder_t::identity,
float fmin = 0, float fmax = 1, float eps = 1e-10 )

The frequency function g(f ) defines the sweep speed and sign (based on the group delay). It
must be defined in the interval [0,1) and should return values in the interval [0,1].
Zτ
Φ(f ) = −4πτ

g(f ) df,

S(f ) = eiΦ(f )

0

Parameters
len

Length τ of the Schroeder tone complex in samples.

channels
freqfun

Number of channels.
Frequency function g(f ).

fmin

Start frequency (relative to Nyquist frequency).

fmax

End frequency (relative to Nyquist frequency).

eps

Stability constant for frequency ranges not covered by Schroeder tone complex.

4.131

MHASignal::spectrum_t Class Reference

a signal processing class for spectral data (based on mha_spec_t (p. 141))
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CONTENTS

Inheritance diagram for MHASignal::spectrum_t:

mha_spec_t

MHASignal::spectrum_t

MHA_AC::spectrum_t

Public Member Functions
• spectrum_t (const unsigned int &frames, const unsigned int &channels)
constructor of spectrum class

• spectrum_t (const mha_spec_t &)
Copy constructor.

• spectrum_t (const MHASignal::spectrum_t &)
Copy constructor.

• mha_complex_t & operator() (unsigned int f, unsigned int ch)
Access to element.

• mha_complex_t & operator[ ] (unsigned int k)
Access to a single element, direct index into data buffer.

• mha_complex_t & value (unsigned int f, unsigned int ch)
Access to element.

• void copy (const mha_spec_t &)
copy all elements from a spectrum

• void copy_channel (const mha_spec_t &s, unsigned sch, unsigned dch)
Copy one channel of a given spectrum signal to a target channel.

• void export_to (mha_spec_t &)
copy elements to spectrum structure

• void scale (const unsigned int &, const unsigned int &, const unsigned int &, const mha←_real_t &)
scale section [a,b) in channel "ch" by "val"

• void scale_channel (const unsigned int &, const mha_real_t &)
scale all elements in one channel
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MHASignal::spectrum_t Class Reference

263

Additional Inherited Members
4.131.1

Constructor & Destructor Documentation

4.131.1.1

spectrum_t::spectrum_t ( const unsigned int & frames, const unsigned int & channels )

Allocates buffers and initializes memory to zeros.
Parameters
frames
channels

4.131.2

number of frames (fft bins) in one channel. Number of Frames is usually fftlen /
2+1
number of channels

Member Function Documentation

4.131.2.1 mha_complex_t& MHASignal::spectrum_t::operator() ( unsigned int f, unsigned int ch )
[inline]
Parameters
f
ch

Bin number
Channel number

Returns
Reference to element

4.131.2.2 mha_complex_t& MHASignal::spectrum_t::operator[ ] ( unsigned int k ) [inline]
Parameters
k

Buffer index

Returns
Reference to element

4.131.2.3 mha_complex_t& MHASignal::spectrum_t::value ( unsigned int f, unsigned int ch )
[inline]

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Parameters
Bin number
Channel number

f
ch

Returns
Reference to element

4.131.2.4

void spectrum_t::copy ( const mha_spec_t & src )

Parameters
src

input spectrum

4.131.2.5

void spectrum_t::copy_channel ( const mha_spec_t & s, unsigned sch, unsigned dch )

Parameters
s

Input spectrum signal

sch

Channel index in source signal

dch

Channel index in destination (this) signal

4.131.2.6

void spectrum_t::export_to ( mha_spec_t & dest )

Parameters
destination spectrum structure

dest

4.131.2.7

void spectrum_t::scale ( const unsigned int & a, const unsigned int & b, const unsigned int &
ch, const mha_real_t & val )

Parameters
a

starting frame

b
ch
val

end frame (excluded)
channel number
scale factor

4.131.2.8

void spectrum_t::scale_channel ( const unsigned int & ch, const mha_real_t & src )

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MHASignal::subsample_delay_t Class Reference

265

Parameters
ch
src

4.132

channel number
scale factor

MHASignal::subsample_delay_t Class Reference

implements subsample delay in spectral domain.

Public Member Functions
• subsample_delay_t (const std::vector< float > &subsample_delay, unsigned fftlen)
Constructor computes complex phase factors to apply to achieve subsample delay.

• void process (mha_spec_t ∗s)
Apply the phase_gains to s to achieve the subsample delay.

• void process (mha_spec_t ∗s, unsigned idx)
Apply the pase gains to channel idx in s to achieve the subsample delay in channel idx.

Public Attributes
• spectrum_t phase_gains
The complex factors to apply to achieve the necessary phase shift.

Private Attributes
• unsigned last_complex_bin
index of the last complex fft bin for the used fft length.

4.132.1

Detailed Description

When transformed back to the time domain, the signal is delayed by the configured fraction of
a sample. This operation must not be used in a smoothgains bracket.

4.132.2
4.132.2.1

Constructor & Destructor Documentation
MHASignal::subsample_delay_t::subsample_delay_t ( const std::vector< float > &
subsample_delay, unsigned fftlen )

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CONTENTS

Parameters
subsample_delay

The subsample delay to apply. -0.5 <= subsample_delay <= 0.5

fftlen

FFT length

Exceptions
MHA_Error ( p. 132)

4.132.3

if the parameters are out of range

Member Function Documentation
void MHASignal::subsample_delay_t::process ( mha_spec_t ∗ s, unsigned idx )

4.132.3.1

Parameters
s
idx

signal
channel index, 0-based

Exceptions
MHA_Error ( p. 132)

4.132.4

Member Data Documentation

4.132.4.1

4.133

if idx >= s->num_channels

unsigned MHASignal::subsample_delay_t::last_complex_bin [private]

MHASignal::uint_vector_t Class Reference

Vector of unsigned values, used for size and index description of n-dimensional matrixes.
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4.133

MHASignal::uint_vector_t Class Reference

Inheritance diagram for MHASignal::uint_vector_t:

MHASignal::uint_vector_t

MHASignal::matrix_t

MHA_AC::ac2matrix_t

Public Member Functions
• uint_vector_t (unsigned int len)
Constructor, initializes all elements to zero.

• uint_vector_t (const uint8_t ∗buf, unsigned int len)
Construct from memory area.

• bool operator== (const uint_vector_t &) const
Check for equality.

• uint_vector_t & operator= (const uint_vector_t &)
Assign from other uint_vector_t ( p. 266).

• unsigned int get_length () const
Return the length of the vector.

• const uint32_t & operator[ ] (unsigned int k) const
Read-only access to elements.

• uint32_t & operator[ ] (unsigned int k)
Access to elements.

• unsigned int numbytes () const
Return number of bytes needed to store into memory.

• unsigned int write (uint8_t ∗buf, unsigned int len) const
Copy to memory area.

• const uint32_t ∗ getdata () const
Return pointer to the data field.

4.133.1
4.133.1.1

Constructor & Destructor Documentation
MHASignal::uint_vector_t::uint_vector_t ( unsigned int len )

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267

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CONTENTS

Parameters
Length of vector.

len

4.133.1.2

MHASignal::uint_vector_t::uint_vector_t ( const uint8_t ∗ buf, unsigned int len )

Warning
This constructor is not real time safe

4.133.2

Member Function Documentation

4.133.2.1 uint_vector_t & MHASignal::uint_vector_t::operator= ( const uint_vector_t & src )
Warning
This assignment will fail if the lengths mismatch.

4.133.2.2

unsigned int MHASignal::uint_vector_t::numbytes ( ) const

4.133.2.3

unsigned int MHASignal::uint_vector_t::write ( uint8_t ∗ buf, unsigned int len ) const

4.133.2.4

const uint32_t∗ MHASignal::uint_vector_t::getdata ( ) const [inline]

4.134

MHASignal::waveform_t Class Reference

signal processing class for waveform data (based on mha_wave_t (p. 154))
Inheritance diagram for MHASignal::waveform_t:

MHA_AC::waveform_t
MHAFilter::o1flt_maxtrack_t
MHAFilter::o1_ar_filter_t

MHAFilter::o1flt_lowpass_t

MHAOvlFilter::fftfb_t

MHAOvlFilter::overlap
_save_filterbank_t

MHAFilter::o1flt_mintrack_t

MHASignal::async_rmslevel_t
mha_wave_t

MHASignal::waveform_t
MHASignal::loop_wavefragment_t
MHAWindow::bartlett_t
MHASignal::ringbuffer_t
MHAWindow::blackman_t
MHASignal::schroeder_t
MHAWindow::fun_t

MHAWindow::hamming_t

MHAWindow::user_t

MHAWindow::hanning_t

MHAWindow::base_t

MHAWindow::rect_t

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MHASignal::waveform_t Class Reference

269

Public Member Functions
• waveform_t (const unsigned int &frames, const unsigned int &channels)
constructor of waveform_t ( p. 268)

• waveform_t (const mhaconfig_t &cf)
Constructor to create a waveform from plugin configuration.

• waveform_t (const mha_wave_t &src)
Copy contructor for mha_wave_t ( p. 154) source.

• waveform_t (const MHASignal::waveform_t &src)
Copy contructor.

• waveform_t (const std::vector< mha_real_t > &src)
Copy contructor for std::vector source.

• mha_real_t & value (unsigned int t, unsigned int ch)
Element accessor.

• mha_real_t & operator() (unsigned int t, unsigned int ch)
Element accessor.

• const mha_real_t & value (unsigned int t, unsigned int ch) const
Constant element accessor.

• const mha_real_t & operator() (unsigned int t, unsigned int ch) const
Constant element accessor.

• mha_real_t sum (const unsigned int &a, const unsigned int &b)
sum of all elements between [a,b) in all channels

• mha_real_t sum (const unsigned int &a, const unsigned int &b, const unsigned int &ch)
sum of all elements between [a,b) in channel ch

• mha_real_t sum ()
sum of all elements

• mha_real_t sumsqr ()
sum of square of all elements

• mha_real_t sum_channel (const unsigned int &)
return sum of all elements in one channel

• void assign (const unsigned int &k, const unsigned int &ch, const mha_real_t &val)
set frame "k" in channel "ch" to value "val"

• void assign (const mha_real_t &)
set all elements to value

• void assign_frame (const unsigned int &k, const mha_real_t &val)
assign value "val" to frame k in all channels

• void assign_channel (const unsigned int &c, const mha_real_t &val)
assign value "val" to channel ch in all frames

• void copy (const mha_wave_t &)
copy data from source into current waveform

• void copy_channel (const mha_wave_t &, unsigned int, unsigned int)
Copy one channel of a given waveform signal to a target channel.

• void copy_from_at (unsigned int, unsigned int, const mha_wave_t &, unsigned int)
Copy part of the source signal into part of this waveform object.

• void export_to (mha_wave_t &)
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CONTENTS

copy data into allocated mha_wave_t ( p. 154) structure

• void limit (const mha_real_t &min, const mha_real_t &max)
limit target to range [min,max]

• void power (const waveform_t &)
transform waveform signal (in Pa) to squared signal (in W/m∧ 2)

• void powspec (const mha_spec_t &)
get the power spectrum (in W/m∧ 2) from a complex spectrum

• void scale (const unsigned int &a, const unsigned int &b, const unsigned int &ch, const
mha_real_t &val)
scale section [a,b) in channel "ch" by "val"

• void scale (const unsigned int &k, const unsigned int &ch, const mha_real_t &val)
scale one element

• void scale_channel (const unsigned int &, const mha_real_t &)
scale one channel of target with a scalar

Additional Inherited Members
4.134.1
4.134.1.1

Constructor & Destructor Documentation
waveform_t::waveform_t ( const unsigned int & frames, const unsigned int & channels )

Allocates buffer memory and initializes values to zero.
Parameters
frames
channels

4.134.1.2

number of frames in each channel
number of channels

waveform_t::waveform_t ( const mhaconfig_t & cf ) [explicit]

Parameters
cf

Plugin configuration

4.134.1.3

waveform_t::waveform_t ( const std::vector< mha_real_t > & src )

A waveform structure with a single channel is created, the length is equal to the number of
elements in the source vector.
4.134.2

Member Function Documentation

4.134.2.1 mha_real_t& MHASignal::waveform_t::value ( unsigned int t, unsigned int ch )
[inline]

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MHASignal::waveform_t Class Reference

271

Parameters
t
ch

Frame number
Channel number

Returns
Reference to element

4.134.2.2 mha_real_t& MHASignal::waveform_t::operator() ( unsigned int t, unsigned int ch )
[inline]
Parameters
t
ch

Frame number
Channel number

Returns
Reference to element

4.134.2.3

const mha_real_t& MHASignal::waveform_t::value ( unsigned int t, unsigned int ch ) const
[inline]

Parameters
t
ch

Frame number
Channel number

Returns
Reference to element

4.134.2.4

const mha_real_t& MHASignal::waveform_t::operator() ( unsigned int t, unsigned int ch )
const [inline]

Parameters
t
ch

Frame number
Channel number

Returns
Reference to element

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CONTENTS

4.134.2.5 mha_real_t waveform_t::sum ( const unsigned int & a, const unsigned int & b )
Parameters
a

starting frame

b

end frame (excluded)

Returns
sum

4.134.2.6 mha_real_t waveform_t::sum ( const unsigned int & a, const unsigned int & b, const
unsigned int & ch )
Parameters
a

starting frame

b
ch

end frame (exluded)
channel number

Returns
sum

4.134.2.7 mha_real_t waveform_t::sum ( )
Returns
sum of all elements

4.134.2.8 mha_real_t waveform_t::sumsqr ( )
Returns
sum of square of all elements

4.134.2.9 mha_real_t waveform_t::sum_channel ( const unsigned int & ch )
Parameters
ch

channel number

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MHASignal::waveform_t Class Reference

273

Returns
sum

4.134.2.10

void waveform_t::assign ( const unsigned int & k, const unsigned int & ch, const
mha_real_t & val )

Parameters
k
ch
val

frame number
channel number
new value

4.134.2.11

void waveform_t::assign ( const mha_real_t & val )

Parameters
val

new value

4.134.2.12

void waveform_t::assign_frame ( const unsigned int & k, const mha_real_t & val )

Parameters
k
val

frame number
new value

4.134.2.13

void waveform_t::assign_channel ( const unsigned int & ch, const mha_real_t & val )

Parameters
ch
val

channel number
new value

4.134.2.14

void waveform_t::copy ( const mha_wave_t & src )

Parameters
src

input data (need to be same size as target)

4.134.2.15

void waveform_t::copy_channel ( const mha_wave_t & src, unsigned int src_channel,
unsigned int dest_channel )

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CONTENTS

Parameters
src

Input waveform signal

src_channel

Channel in source signal

dest_channel

Channel number in destination signal

4.134.2.16

void waveform_t::copy_from_at ( unsigned int to_pos, unsigned int len, const
mha_wave_t & src, unsigned int from_pos )

Source and target have to have the same number of channels.
Parameters
to_pos

Offset in target

len

Number of frames copied

src
from_pos

Source
Offset in source

4.134.2.17

void waveform_t::export_to ( mha_wave_t & dest )

Parameters
dest

destination structure

4.134.2.18

void waveform_t::limit ( const mha_real_t & min, const mha_real_t & max )

Parameters
min
max

lower limit
upper limit

4.134.2.19

void waveform_t::power ( const waveform_t & src )

Parameters
src

linear waveform signal (in Pa)

4.134.2.20

void waveform_t::powspec ( const mha_spec_t & src )

Parameters
src

complex spectrum (normalized to Pa)

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MHATableLookup::xy_table_t Class Reference

4.134.2.21

275

void waveform_t::scale ( const unsigned int & a, const unsigned int & b, const unsigned int
& ch, const mha_real_t & val )

Parameters
a

starting frame

b
ch
val

end frame (excluded)
channel number
scale factor

4.134.2.22

void waveform_t::scale ( const unsigned int & k, const unsigned int & ch, const
mha_real_t & val )

Parameters
k
ch
val

frame number
channel number
scale factor

4.134.2.23

void waveform_t::scale_channel ( const unsigned int & ch, const mha_real_t & src )

Parameters
ch
src

4.135

channel number
factor

MHATableLookup::xy_table_t Class Reference

Class for interpolation with non-equidistant x values.
Inherits MHATableLookup::table_t.
Inherited by MHAOvlFilter::barkscale::bark2hz_t, and MHAOvlFilter::barkscale::hz2bark_t.

Public Member Functions
• mha_real_t lookup (mha_real_t x) const
Return the y-value at the position of the nearest x value below input.

• mha_real_t interp (mha_real_t x) const
Linear interpolation function.

• void add_entry (mha_real_t x, mha_real_t y)
Add a single x-y pair entry.

• void add_entry (mha_real_t ∗pVX, mha_real_t ∗pVY, unsigned int len)
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CONTENTS

Add multiple entries at once.

• void clear ()
Clear the table and transformation functions.

• void set_xfun (float(∗pXFun)(float))
Set transformation function for x values.

• void set_yfun (float(∗pYFun)(float))
Set transformation function for y values during insertion.

• void set_xyfun (float(∗pYFun)(float, float))
Set transformation function for y values during insertion, based on x and y values.

4.135.1

Detailed Description

Linear interpolation of the x-y table is performed. A transformation of x and y-values is possible;
if a transformation function is provided for the x-values, the same function is applied to the argument of xy_table_t::interp() (p. 276) and xy_table_t::lookup() (p. 276). The transformation
of y values is applied only during insertion into the table. Two functions for y-transformation
can be provided: a simple transformation which depends only on the y values, or a transformation which takes both (non-transformed) x and y value as an argument. The two-argument
transformation is applied before the one-argument transformation.

4.135.2

Member Function Documentation

4.135.2.1 mha_real_t xy_table_t::lookup ( mha_real_t x ) const
Parameters
x

Input value

Returns
y value at nearest x value below input.

4.135.2.2 mha_real_t xy_table_t::interp ( mha_real_t x ) const
Parameters
x

x value

Returns
interpolated y value
4.135.2.3

void xy_table_t::add_entry ( mha_real_t x, mha_real_t y )

© 2005-2018 HörTech gGmbH, Oldenburg

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MHAWindow::bartlett_t Class Reference

277

Parameters
x
y

x value
corresponding y value

4.135.2.4

void xy_table_t::add_entry ( mha_real_t ∗ pVX, mha_real_t ∗ pVY, unsigned int uLength )

Parameters
pVX

array of x values

pVY

array of y values

uLength

Length of x and y arrays

4.135.2.5

void xy_table_t::set_xfun ( float(∗)(float) fun )

Parameters
fun

Transformation function.

4.135.2.6

void xy_table_t::set_yfun ( float(∗)(float) fun )

Parameters
fun

Transformation function.

4.135.2.7

void xy_table_t::set_xyfun ( float(∗)(float, float) fun )

Parameters
fun

4.136

Transformation function.

MHAWindow::bartlett_t Class Reference

Bartlett window.
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CONTENTS

Inheritance diagram for MHAWindow::bartlett_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::bartlett_t

Additional Inherited Members

4.137

MHAWindow::base_t Class Reference

Common base for window types.
Inheritance diagram for MHAWindow::base_t:

MHAWindow::bartlett_t

MHAWindow::blackman_t

mha_wave_t

MHASignal::waveform_t

MHAWindow::fun_t

MHAWindow::hamming_t

MHAWindow::user_t

MHAWindow::hanning_t

MHAWindow::base_t

MHAWindow::rect_t

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MHAWindow::blackman_t Class Reference

279

Public Member Functions
• base_t (unsigned int len)
Constructor.

• base_t (const MHAWindow::base_t &src)
Copy constructor.

• void operator() (mha_wave_t &) const
Apply window to waveform segment (reference)

• void operator() (mha_wave_t ∗) const
Apply window to waveform segment (pointer)

• void ramp_begin (mha_wave_t &) const
Apply a ramp at the begining.

• void ramp_end (mha_wave_t &) const
Apply a ramp at the end.

Additional Inherited Members
4.137.1

Constructor & Destructor Documentation

4.137.1.1

MHAWindow::base_t::base_t ( unsigned int len )

Parameters
len

Window length in samples.

4.137.1.2

MHAWindow::base_t::base_t ( const MHAWindow::base_t & src )

Parameters
src

4.138

Source to be copied

MHAWindow::blackman_t Class Reference

Blackman window.
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CONTENTS

Inheritance diagram for MHAWindow::blackman_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::blackman_t

Additional Inherited Members

4.139

MHAWindow::fun_t Class Reference

Generic window based on a generator function.
Inheritance diagram for MHAWindow::fun_t:

MHAWindow::bartlett_t

MHAWindow::blackman_t

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::hamming_t

MHAWindow::hanning_t

MHAWindow::rect_t

Public Member Functions
• fun_t (unsigned int n, float(∗fun)(float), float xmin=-1, float xmax=1, bool min_←included=true, bool max_included=false)
Constructor.
© 2005-2018 HörTech gGmbH, Oldenburg

4.140

MHAWindow::hamming_t Class Reference

281

Additional Inherited Members
4.139.1

Detailed Description

The generator function should return a valid window function in the interval [-1,1[.

4.139.2

Constructor & Destructor Documentation

4.139.2.1

MHAWindow::fun_t::fun_t ( unsigned int n, float(∗)(float) fun, float xmin = -1, float xmax = 1,
bool min_included = true, bool max_included = false )

Parameters
n

Window length

fun

Generator function, i.e. MHAWindow::hanning() (p. 305)

xmin

Start value of window, i.e. -1 for full window or 0 for fade-out ramp.

xmax
min_included

Last value of window, i.e. 1 for full window
Flag if minimum value is included

max_included

Flag if maximum value is included

4.140

MHAWindow::hamming_t Class Reference

Hamming window.
© 2005-2018 HörTech gGmbH, Oldenburg

282

CONTENTS

Inheritance diagram for MHAWindow::hamming_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::hamming_t

Additional Inherited Members

4.141

MHAWindow::hanning_t Class Reference

von-Hann window
© 2005-2018 HörTech gGmbH, Oldenburg

4.142

MHAWindow::rect_t Class Reference

Inheritance diagram for MHAWindow::hanning_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::hanning_t

Additional Inherited Members

4.142

MHAWindow::rect_t Class Reference

Rectangular window.
© 2005-2018 HörTech gGmbH, Oldenburg

283

284

CONTENTS

Inheritance diagram for MHAWindow::rect_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::fun_t

MHAWindow::rect_t

Additional Inherited Members

4.143

MHAWindow::user_t Class Reference

User defined window.
© 2005-2018 HörTech gGmbH, Oldenburg

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PluginLoader::fourway_processor_t Class Reference

285

Inheritance diagram for MHAWindow::user_t:

mha_wave_t

MHASignal::waveform_t

MHAWindow::base_t

MHAWindow::user_t

Public Member Functions
• user_t (const std::vector< mha_real_t > &wnd)
Constructor.

Additional Inherited Members
4.143.1

Constructor & Destructor Documentation

4.143.1.1

MHAWindow::user_t::user_t ( const std::vector< mha_real_t > & wnd )

Parameters
wnd

4.144

User defined window

PluginLoader::fourway_processor_t Class Reference

This abstract class defines the interface for classes that implement all types of signal domain
processing supported by the MHA: wave2wave, spec2spec, wave2spec, and spec2wave.
Inherited by PluginLoader::mhapluginloader_t.
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CONTENTS

Public Member Functions
• virtual void process (mha_wave_t ∗s_in, mha_wave_t ∗∗s_out)=0
Pure waveform processing.

• virtual void process (mha_spec_t ∗s_in, mha_spec_t ∗∗s_out)=0
Pure spectrum processing.

• virtual void process (mha_wave_t ∗s_in, mha_spec_t ∗∗s_out)=0
Signal processing with domain transformation from waveform to spectrum.

• virtual void process (mha_spec_t ∗s_in, mha_wave_t ∗∗s_out)=0
Signal processing with domain transformation from spectrum to waveform.

• virtual void prepare (mhaconfig_t &settings)=0
Prepares the processor for signal processing.

• virtual void release ()=0
Resources allocated for signal processing in fourway_processor_t::prepare ( p. 287) are released here in fourway_processor_t::release ( p. 287).

• virtual std::string parse (const std::string &query)=0
Parser interface.

• virtual ∼fourway_processor_t ()
Classes with virtual methods need virtual destructor.

4.144.1

Detailed Description

For supporting different output domains for the same input domain, the processing methods
are overloaded with respect to input domain and output domain.

4.144.2
4.144.2.1

Constructor & Destructor Documentation
virtual PluginLoader::fourway_processor_t::∼fourway_processor_t (
[virtual]

) [inline],

This destructor is empty.

4.144.3
4.144.3.1

Member Function Documentation
virtual void PluginLoader::fourway_processor_t::process ( mha_wave_t ∗ s_in,
mha_wave_t ∗∗ s_out ) [pure virtual]

Parameters
s_in

input waveform signal

s_out

output waveform signal

© 2005-2018 HörTech gGmbH, Oldenburg

5 File Documentation

4.144.3.2

287

virtual void PluginLoader::fourway_processor_t::process ( mha_spec_t ∗ s_in,
mha_spec_t ∗∗ s_out ) [pure virtual]

Parameters
s_in
s_out

4.144.3.3

input spectrum signal
output spectrum signal

virtual void PluginLoader::fourway_processor_t::process ( mha_wave_t ∗ s_in,
mha_spec_t ∗∗ s_out ) [pure virtual]

Parameters
s_in
s_out

4.144.3.4

input waveform signal
output spectrum signal

virtual void PluginLoader::fourway_processor_t::process ( mha_spec_t ∗ s_in,
mha_wave_t ∗∗ s_out ) [pure virtual]

Parameters
s_in

input spectrum signal

s_out

output waveform signal

4.144.3.5

virtual void PluginLoader::fourway_processor_t::prepare ( mhaconfig_t & settings )
[pure virtual]

Parameters
settings

4.144.3.6

domain and dimensions of the signal. The contents of settings may be modified
by the prepare implementation. Upon calling fourway_processor_t::prepare
(p. 287), settings reflects domain and dimensions of the input signal. When
fourway_processor_t::prepare (p. 287) returns, settings reflects domain and
dimensions of the output signal.

virtual void PluginLoader::fourway_processor_t::release ( ) [pure virtual]

5

File Documentation

5.1

mha.h File Reference

common types for MHA kernel, MHA framework applications and external plugins
© 2005-2018 HörTech gGmbH, Oldenburg

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CONTENTS

Classes
• struct mha_complex_t
Type for complex floating point values.

• struct mha_direction_t
Channel source direction structure.

• struct mha_channel_info_t
Channel information structure.

• struct mha_wave_t
Waveform signal structure.

• struct mha_spec_t
Spectrum signal structure.

• struct mha_audio_descriptor_t
Description of an audio fragment (planned as a replacement of mhaconfig_t ( p. 155)).

• struct mha_audio_t
An audio fragment in the openMHA (planned as a replacement of mha_wave_t ( p. 154) and
mha_spec_t ( p. 141)).

• struct mhaconfig_t
MHA prepare configuration structure.

• struct comm_var_t
Algorithm communication variable structure.

• struct algo_comm_t
A reference handle for algorithm communication variables.

Macros
• #define MHA_CALLBACK_TEST(x)
Test macro to compare function type definition and declaration.

• #define MHA_VERSION_MAJOR 4
Major version number of MHA.

• #define MHA_VERSION_MINOR 5
Minor version number of MHA.

• #define MHA_VERSION_RELEASE 5
Release number of MHA.

• #define MHA_VERSION_BUILD 0
Build number of MHA (currently unused)

• #define MHA_STRUCT_SIZEMATCH (unsigned int)((sizeof(mha_real_t)==4)+2∗(sizeof(mha←_complex_t)==8)+4∗(sizeof(mha_wave_t)==8+2∗sizeof(void∗))+8∗(sizeof(mha_spec←_t)==8+2∗sizeof(void∗))+16∗(sizeof(mhaconfig_t)==24))
Test number for structure sizes.

• #define MHA_VERSION (unsigned int)((MHA_STRUCT_SIZEMATCH | (MHA_VERS←ION_RELEASE << 8) | (MHA_VERSION_MINOR << 16) | (MHA_VERSION_MAJOR
<< 24)))
Full version number of MHA kernel.
© 2005-2018 HörTech gGmbH, Oldenburg

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mha_algo_comm.h File Reference

289

• #define MHA_VERSION_STRING MHA_XSTRF(MHA_VERSION_MAJOR) "." MHA_←XSTRF(MHA_VERSION_MINOR)
Version string of MHA kernel (major.minor)

• #define MHA_RELEASE_VERSION_STRING MHA_XSTRF(MHA_VERSION_MAJOR)
"." MHA_XSTRF(MHA_VERSION_MINOR) "." MHA_XSTRF(MHA_VERSION_RELE←ASE)
Version string of MHA kernel (major.minor.release)

Typedefs
• typedef float mha_real_t
openMHA type for real numbers

• typedef void ∗ mha_fft_t
Handle for an FFT object.

5.2

mha_algo_comm.h File Reference

Header file for Algorithm Communication.

Classes
• class MHA_AC::spectrum_t
Insert a MHASignal::spectrum_t ( p. 261) class into the AC space.

• class MHA_AC::waveform_t
Insert a MHASignal::waveform_t ( p. 268) class into the AC space.

• class MHA_AC::int_t
Insert a integer variable into the AC space.

• class MHA_AC::float_t
Insert a float point variable into the AC space.

• class MHA_AC::double_t
Insert a double precision floating point variable into the AC space.

• class MHA_AC::ac2matrix_t
Copy AC variable to a matrix.

• class MHA_AC::acspace2matrix_t
Copy all or a subset of all numeric AC variables into an array of matrixes.

Namespaces
• MHA_AC
Functions and classes for Algorithm Communication (AC) support.
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CONTENTS

Functions
• mha_spec_t MHA_AC::get_var_spectrum (algo_comm_t ac, const std::string &name)
Convert an AC variable into a spectrum.

• mha_wave_t MHA_AC::get_var_waveform (algo_comm_t ac,
&name)

const std::string

Convert an AC variable into a waveform.

• int MHA_AC::get_var_int (algo_comm_t ac, const std::string &name)
Return value of an integer scalar AC variable.

• float MHA_AC::get_var_float (algo_comm_t ac, const std::string &name)
Return value of an floating point scalar AC variable.

• std::vector< float > MHA_AC::get_var_vfloat (algo_comm_t ac, const std::string
&name)
Return value of an floating point vector AC variable as standard vector of floats.

5.3

mha_defs.h File Reference

Preprocessor definitions common to all MHA components.

Macros
• #define M_PI 3.14159265358979323846
Define pi if it is not defined yet.

• #define MIN(a, b) (((a)<(b))?(a):(b))
Macro for minimum function.

• #define MAX(a, b) (((a)>(b))?(a):(b))
Macro for maximum function.

5.3.1

Detailed Description

This file contains all preprocessor and type definitions which are common to all Master Hearing
Aid components.

5.4

mha_error.cpp File Reference

Implementation of openMHA error handling.
© 2005-2018 HörTech gGmbH, Oldenburg

5.5

mha_filter.hh File Reference

291

Functions
• unsigned mha_error_helpers::digits (unsigned n)
Compute number of decimal digits required to represent an unsigned integer.

• unsigned mha_error_helpers::snprintf_required_length (const char ∗formatstring,...)
snprintf_required_length Compute the number of bytes (excluding the terminating nul) required
to store the result of an snprintf.

• void mha_debug (const char ∗fmt,...)
Print an info message (stderr on Linux, OutputDebugString in Windows).

5.4.1

Detailed Description

This file forms a seperate library.

5.4.2

Function Documentation

5.4.2.1

unsigned mha_error_helpers::digits ( unsigned n )

Parameters
n

The unsigned integer that we want to know the number of required decimal digits for.
return The number of decimal digits in n.

5.4.2.2

unsigned mha_error_helpers::snprintf_required_length ( const char ∗ formatstring, ... )

Parameters
formatstring

The format string with standard printf formatstring

Returns
the number of bytes required by printf without the terminating nul

5.5

mha_filter.hh File Reference

Header file for IIR filter classes.

Classes
• class MHAFilter::filter_t
Generic IIR filter class.
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CONTENTS

• class MHAFilter::diff_t
Differentiator class (non-normalized)

• class MHAFilter::o1_ar_filter_t
First order attack-release lowpass filter.

• class MHAFilter::o1flt_lowpass_t
First order low pass filter.

• class MHAFilter::o1flt_maxtrack_t
First order maximum tracker.

• class MHAFilter::o1flt_mintrack_t
First order minimum tracker.

• class MHAFilter::iir_filter_t
IIR filter class wrapper for integration into parser structure.

• class MHAFilter::adapt_filter_t
Adaptive filter.

• class MHAFilter::fftfilter_t
FFT based FIR filter implementation.

• class MHAFilter::fftfilterbank_t
FFT based FIR filterbank implementation.

• struct MHAFilter::transfer_function_t
a structure containing a source channel number, a target channel number, and an impulse
response.

• struct MHAFilter::transfer_matrix_t
A sparse matrix of transfer function partitionss.

• class MHAFilter::partitioned_convolution_t
A filter class for partitioned convolution.

• struct MHAFilter::partitioned_convolution_t::index_t
Bookkeeping class.

• class MHAFilter::smoothspec_t
Smooth spectral gains, create a windowed impulse response.

• class MHAFilter::resampling_filter_t
Hann shaped low pass filter for resampling.

• class MHAFilter::polyphase_resampling_t
A class that does polyphase resampling.

• class MHAFilter::blockprocessing_polyphase_resampling_t
A class that does polyphase resampling and takes into account block processing.

• class MHAFilter::iir_ord1_real_t
First order recursive filter.

Namespaces
• MHAFilter
Namespace for IIR and FIR filter classes.
© 2005-2018 HörTech gGmbH, Oldenburg

5.6

mha_parser.hh File Reference

293

Functions
• void MHAFilter::o1_lp_coeffs (const mha_real_t tau, const mha_real_t fs, mha_real←_t &c1, mha_real_t &c2)
Set first order filter coefficients from time constant and sampling rate.

• void MHAFilter::butter_stop_ord1 (double ∗A, double ∗B, double f1, double f2, double
fs)
Setup a first order butterworth band stop filter.

• MHASignal::waveform_t ∗ MHAFilter::spec2fir (const mha_spec_t ∗spec, const unsigned int fftlen, const MHAWindow::base_t &window, const bool minphase)
Create a windowed impulse response/FIR filter coefficients from a spectrum.

• unsigned MHAFilter::gcd (unsigned a, unsigned b)
greatest common divisor

• double MHAFilter::sinc (double x)
sin(x)/x function, coping with x=0.

• std::pair< unsigned, unsigned > MHAFilter::resampling_factors (float source_←sampling_rate, float target_sampling_rate, float factor=1.0f)
Computes rational resampling factor from two sampling rates.

5.6

mha_parser.hh File Reference

Header file for the MHA-Parser script language.

Classes
• class MHAParser::keyword_list_t
Keyword list class.

• class MHAParser::base_t
Base class for all parser items.

• class MHAParser::parser_t
Parser node class.

• class MHAParser::monitor_t
Base class for monitors and variable nodes.

• class MHAParser::variable_t
Base class for variable nodes.

• class MHAParser::range_var_t
Base class for all variables with a numeric value range.

• class MHAParser::kw_t
Variable with keyword list value.

• class MHAParser::string_t
Variable with a string value.

• class MHAParser::vstring_t
Vector variable with string values.

• class MHAParser::bool_t
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Variable with a boolean value ("yes"/"no")

• class MHAParser::int_t
Variable with integer value.

• class MHAParser::float_t
Variable with float value.

• class MHAParser::complex_t
Variable with complex value.

• class MHAParser::vint_t
Variable with vector value.

• class MHAParser::vfloat_t
Vector variable with float value.

• class MHAParser::vcomplex_t
Vector variable with complex value.

• class MHAParser::mfloat_t
Matrix variable with float value.

• class MHAParser::mcomplex_t
Matrix variable with complex value.

• class MHAParser::int_mon_t
Monitor variable with int value.

• class MHAParser::bool_mon_t
Monitor with string value.

• class MHAParser::string_mon_t
Monitor with string value.

• class MHAParser::vstring_mon_t
Vector of monitors with string value.

• class MHAParser::vint_mon_t
Vector of ints monitor.

• class MHAParser::vfloat_mon_t
Vector of floats monitor.

• class MHAParser::mfloat_mon_t
Matrix of floats monitor.

• class MHAParser::float_mon_t
Monitor with float value.

• class MHAParser::complex_mon_t
Monitor with complex value.

• class MHAParser::vcomplex_mon_t
Monitor with vector of complex values.

• class MHAParser::mcomplex_mon_t
Matrix of complex numbers monitor.

• class MHAParser::commit_t< receiver_t >
Parser variable with event-emission functionality.
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Namespaces
• MHAParser
Name space for the openMHA-Parser configuration language.

• MHAParser::StrCnv
String converter namespace.

Macros
• #define insert_member(x) insert_item(#x,&x)
Macro to insert a member variable into a parser.

Functions
• void MHAParser::strreplace (std::string &, const std::string &, const std::string &)
string replace function

• void MHAParser::StrCnv::str2val (const std::string &, bool &)
Convert from string.

• void MHAParser::StrCnv::str2val (const std::string &, float &)
Convert from string.

• void MHAParser::StrCnv::str2val (const std::string &, mha_complex_t &)
Convert from string.

• void MHAParser::StrCnv::str2val (const std::string &, int &)
Convert from string.

• void MHAParser::StrCnv::str2val (const std::string &, keyword_list_t &)
Convert from string.

• void MHAParser::StrCnv::str2val (const std::string &, std::string &)
Convert from string.

• template
void MHAParser::StrCnv::str2val (const std::string &s, std::vector< arg_t > &val)
Converter for vector types.

• template<>
void MHAParser::StrCnv::str2val< mha_real_t > (const std::string &s, std::vector<
mha_real_t > &v)
Converter for vector with Matlab-style expansion.

• template
void MHAParser::StrCnv::str2val (const std::string &s, std::vector< std::vector< arg_t
> > &val)
Converter for matrix types.

• std::string MHAParser::StrCnv::val2str (const bool &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const float &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const mha_complex_t &)
Convert to string.
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• std::string MHAParser::StrCnv::val2str (const int &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const keyword_list_t &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::string &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< float > &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< mha_complex_t > &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< int > &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< std::string > &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< std::vector< float > > &)
Convert to string.

• std::string MHAParser::StrCnv::val2str (const std::vector< std::vector< mha_←complex_t > > &)
Convert to string.

5.6.1

Macro Definition Documentation

5.6.1.1

#define insert_member( x ) insert_item(#x,&x)

Parameters
x

Member variable to be inserted. Name of member variable will be used as configuration
name.

See also MHAParser::parser_t::insert_item() (p. 222).

5.7

mha_plugin.hh File Reference

Header file for MHA C++ plugin class templates.

Classes
• class MHAPlugin::config_t< runtime_cfg_t >
Template class for thread safe configuration.

• class MHAPlugin::plugin_t< runtime_cfg_t >
The template class for C++ openMHA plugins.
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Namespaces
• MHAPlugin
Namespace for openMHA plugin class templates and thread-safe runtime configurations.

Macros
• #define MHAPLUGIN_CALLBACKS_PREFIX(prefix, classname, indom, outdom)
C++ wrapper macro for the plugin interface.

• #define MHAPLUGIN_CALLBACKS(plugname, classname, indom, outdom) MHAPLU←GIN_CALLBACKS_PREFIX(MHA_STATIC_ ## plugname ## _,classname,indom,outdom)
C++ wrapper macro for the plugin interface.

• #define MHAPLUGIN_DOCUMENTATION(plugname, cat, doc) MHAPLUGIN_DOCU←MENTATION_PREFIX(MHA_STATIC_ ## plugname ## _,cat,doc)
Wrapper macro for the plugin documentation interface.

Functions
• __attribute__ ((unused)) static const char ∗mha_git_commit_hash
store git commit hash in every binary plgin to support reproducible research

5.7.1

Detailed Description

This file defines useful macros and template classes for the development of MHA plugins. A
set of macros wraps a C++ interface around the ANSI-C plugin interface. The plugin_t template
class defines a corresponding C++ class with all required members. This class can make use
of thread safe configurations (config_t).

5.8

mha_signal.hh File Reference

Header file for audio signal handling and processing classes.

Classes
• class MHASignal::spectrum_t
a signal processing class for spectral data (based on mha_spec_t ( p. 141))

• class MHASignal::waveform_t
signal processing class for waveform data (based on mha_wave_t ( p. 154))

• class MHASignal::doublebuffer_t
Double-buffering class.

• class MHASignal::ringbuffer_t
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A ringbuffer class for time domain audio signal, which makes no assumptions with respect to
fragment size.

• class MHASignal::hilbert_t
Hilbert transformation of a waveform segment.

• class MHASignal::minphase_t
Minimal phase function.

• class MHAWindow::base_t
Common base for window types.

• class MHAWindow::fun_t
Generic window based on a generator function.

• class MHAWindow::rect_t
Rectangular window.

• class MHAWindow::bartlett_t
Bartlett window.

• class MHAWindow::hanning_t
von-Hann window

• class MHAWindow::hamming_t
Hamming window.

• class MHAWindow::blackman_t
Blackman window.

• class MHAWindow::user_t
User defined window.

• class MHASignal::delay_wave_t
Delayline containing wave fragments.

• class MHASignal::async_rmslevel_t
Class for asynchronous level metering.

• class MHASignal::uint_vector_t
Vector of unsigned values, used for size and index description of n-dimensional matrixes.

• class MHASignal::matrix_t
n-dimensional matrix with real or complex floating point values.

• class MHASignal::schroeder_t
Schroeder tone complex class.

• class MHASignal::quantizer_t
Simple simulation of fixpoint quantization.

• class MHASignal::loop_wavefragment_t
Copy a fixed waveform fragment to a series of waveform fragments of other size.

• class MHASignal::delay_t
Class to realize a simple delay of waveform streams.

• class MHASignal::subsample_delay_t
implements subsample delay in spectral domain.

Namespaces
• MHASignal
Namespace for audio signal handling and processing classes.

• MHAWindow
Collection of Window types.
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Functions
• void MHASignal::for_each (mha_wave_t ∗s, mha_real_t(∗fun)(mha_real_t))
Apply a function to each element of a mha_wave_t ( p. 154).

• mha_real_t MHASignal::lin2db (mha_real_t x)
Conversion from linear scale to dB (no SPL reference)

• mha_real_t MHASignal::db2lin (mha_real_t x)
Conversion from dB scale to linear (no SPL reference)

• mha_real_t MHASignal::pa2dbspl (mha_real_t x)
Conversion from linear Pascal scale to dB SPL.

• mha_real_t MHASignal::pa22dbspl (mha_real_t x, mha_real_t eps=1e-20f)
Conversion from squared Pascal scale to dB SPL.

• mha_real_t MHASignal::dbspl2pa (mha_real_t x)
Conversion from dB SPL to linear Pascal scale.

• mha_real_t MHASignal::smp2sec (mha_real_t n, mha_real_t srate)
conversion from samples to seconds

• mha_real_t MHASignal::sec2smp (mha_real_t sec, mha_real_t srate)
conversion from seconds to samples

• mha_real_t MHASignal::bin2freq (mha_real_t bin, unsigned fftlen, mha_real_t srate)
conversion from fft bin index to frequency

• mha_real_t MHASignal::freq2bin (mha_real_t freq, unsigned fftlen, mha_real_t srate)
conversion from frequency to fft bin index

• mha_real_t MHASignal::smp2rad (mha_real_t samples, unsigned bin, unsigned fftlen)
conversion from delay in samples to phase shift

• mha_real_t MHASignal::rad2smp (mha_real_t phase_shift, unsigned bin, unsigned
fftlen)
conversion from phase shift to delay in samples

• template
std::vector< elem_type > MHASignal::dupvec (std::vector< elem_type > vec, unsigned
n)
Duplicate last vector element to match desired size.

• template
std::vector< elem_type > MHASignal::dupvec_chk (std::vector< elem_type > vec, unsigned n)
Duplicate last vector element to match desired size, check for dimension.

• bool equal_dim (const mha_wave_t &a, const mha_wave_t &b)
Test for equal dimension of waveform structures.

• bool equal_dim (const mha_wave_t &a, const mhaconfig_t &b)
Test for match of waveform dimension with mhaconfig structure.

• bool equal_dim (const mha_spec_t &a, const mha_spec_t &b)
Test for equal dimension of spectrum structures.

• bool equal_dim (const mha_spec_t &a, const mhaconfig_t &b)
Test for match of spectrum dimension with mhaconfig structure.

• bool equal_dim (const mha_wave_t &a, const mha_spec_t &b)
Test for equal dimension of waveform/spectrum structures.

• bool equal_dim (const mha_spec_t &a, const mha_wave_t &b)
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Test for equal dimension of waveform/spectrum structures.

• void integrate (mha_wave_t &s)
Numeric integration of a signal vector (real values)

• void integrate (mha_spec_t &s)
Numeric integration of a signal vector (complex values)

• unsigned int size (const mha_wave_t &s)
Return size of a waveform structure.

• unsigned int size (const mha_spec_t &s)
Return size of a spectrum structure.

• unsigned int size (const mha_wave_t ∗s)
Return size of a waveform structure.

• unsigned int size (const mha_spec_t ∗s)
Return size of a spectrum structure.

• void clear (mha_wave_t &s)
Set all values of waveform to zero.

• void clear (mha_wave_t ∗s)
Set all values of waveform to zero.

• void clear (mha_spec_t &s)
Set all values of spectrum to zero.

• void clear (mha_spec_t ∗s)
Set all values of spectrum to zero.

• void assign (mha_wave_t self, mha_real_t val)
Set all values of waveform 'self' to 'val'.

• void assign (mha_wave_t self, const mha_wave_t &val)
Set all values of waveform 'self' to 'val'.

• void assign (mha_spec_t self, const mha_spec_t &val)
Set all values of spectrum 'self' to 'val'.

• void timeshift (mha_wave_t &self, int shift)
Time shift of waveform chunk.

• mha_wave_t range (mha_wave_t s, unsigned int k0, unsigned int len)
Return a time interval from a waveform chunk.

• mha_spec_t channels (mha_spec_t s, unsigned int ch_start, unsigned int nch)
Return a channel interval from a spectrum.

• mha_real_t & value (mha_wave_t ∗s, unsigned int fr, unsigned int ch)
Access an element of a waveform structure.

• const mha_real_t & value (const mha_wave_t ∗s, unsigned int fr, unsigned int ch)
Constant access to an element of a waveform structure.

• mha_complex_t & value (mha_spec_t ∗s, unsigned int fr, unsigned int ch)
Access to an element of a spectrum.

• const mha_complex_t & value (const mha_spec_t ∗s, unsigned int fr, unsigned int ch)
Constant access to an element of a spectrum.

• mha_real_t & value (mha_wave_t &s, unsigned int fr, unsigned int ch)
Access to an element of a waveform structure.

• const mha_real_t & value (const mha_wave_t &s, unsigned int fr, unsigned int ch)
Constant access to an element of a waveform structure.
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• mha_complex_t & value (mha_spec_t &s, unsigned int fr, unsigned int ch)
Access to an element of a spectrum.

• const mha_complex_t & value (const mha_spec_t &s, unsigned int fr, unsigned int ch)
Constant access to an element of a spectrum.

• std::vector< float > std_vector_float (const mha_wave_t &)
Converts a mha_wave_t ( p. 154) structure into a std::vector (interleaved order).

• std::vector< std::vector< float > > std_vector_vector_float (const mha_wave_t &)
Converts a mha_wave_t ( p. 154) structure into a std::vector< std::vector > (outer vector represents channels).

• std::vector< std::vector< mha_complex_t > > std_vector_vector_complex (const
mha_spec_t &)
Converts a mha_spec_t ( p. 141) structure into a std::vector< std::vector >
(outer vector represents channels).

• mha_wave_t & operator+= (mha_wave_t &, const mha_real_t &)
Addition operator.

• mha_wave_t & operator+= (mha_wave_t &, const mha_wave_t &)
Addition operator.

• mha_wave_t & operator-= (mha_wave_t &, const mha_wave_t &)
Subtraction operator.

• mha_spec_t & operator-= (mha_spec_t &, const mha_spec_t &)
Subtraction operator.

• mha_wave_t & operator∗= (mha_wave_t &, const mha_real_t &)
Element-wise multiplication operator.

• mha_wave_t & operator∗= (mha_wave_t &, const mha_wave_t &)
Element-wise multiplication operator.

• mha_spec_t & operator∗= (mha_spec_t &, const mha_real_t &)
Element-wise multiplication operator.

• mha_spec_t & operator∗= (mha_spec_t &, const mha_wave_t &)
Element-wise multiplication operator.

• mha_spec_t & operator∗= (mha_spec_t &, const mha_spec_t &)
Element-wise multiplication operator.

• mha_spec_t & operator/= (mha_spec_t &, const mha_spec_t &)
Element-wise division operator.

• mha_wave_t & operator/= (mha_wave_t &, const mha_wave_t &)
Element-wise division operator.

• mha_spec_t & operator+= (mha_spec_t &, const mha_spec_t &)
Addition operator.

• mha_spec_t & operator+= (mha_spec_t &, const mha_real_t &)
Addition operator.

• mha_spec_t & safe_div (mha_spec_t &self, const mha_spec_t &v, mha_real_t eps)
In-Place division with lower limit on divisor.

• mha_wave_t & operator∧ = (mha_wave_t &self, const mha_real_t &arg)
Exponent operator.

• void MHASignal::copy_channel (mha_spec_t &self, const mha_spec_t &src, unsigned
sch, unsigned dch)
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Copy one channel of a source signal.

• void MHASignal::copy_channel (mha_wave_t &self, const mha_wave_t &src, unsigned src_channel, unsigned dest_channel)
Copy one channel of a source signal.

• mha_real_t MHASignal::rmslevel (const mha_spec_t &s, unsigned int channel, unsigned int fftlen)
Return RMS level of a spectrum channel.

• mha_real_t MHASignal::colored_intensity (const mha_spec_t &s, unsigned int channel, unsigned int fftlen, mha_real_t sqfreq_response[ ])
Colored spectrum intensity.

• mha_real_t MHASignal::maxabs (const mha_spec_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t MHASignal::rmslevel (const mha_wave_t &s, unsigned int channel)
Return RMS level of a waveform channel.

• mha_real_t MHASignal::maxabs (const mha_wave_t &s, unsigned int channel)
Find maximal absolute value.

• mha_real_t MHASignal::maxabs (const mha_wave_t &s)
Find maximal absolute value.

• mha_real_t MHASignal::max (const mha_wave_t &s)
Find maximal value.

• mha_real_t MHASignal::min (const mha_wave_t &s)
Find minimal value.

• mha_real_t MHASignal::sumsqr_channel (const mha_wave_t &s, unsigned int channel)
Calculate sum of squared values in one channel.

• mha_real_t MHASignal::sumsqr_frame (const mha_wave_t &s, unsigned int frame)
Calculate sum over all channels of squared values.

• void MHASignal::limit (mha_wave_t &s, const mha_real_t &min, const mha_real_←t &max)
Limit the singal in the waveform buffer to the range [min, max].

• mha_complex_t & set (mha_complex_t &self, mha_real_t real, mha_real_t imag=0)
Assign real and imaginary parts to a mha_complex_t ( p. 123) variable.

• mha_complex_t mha_complex (mha_real_t real, mha_real_t imag=0)
Create a new mha_complex_t ( p. 123) with specified real and imaginary parts.

• mha_complex_t & set (mha_complex_t &self, const std::complex< mha_real_t >
&stdcomplex)
Assign a mha_complex_t ( p. 123) variable from a std::complex.

• std::complex< mha_real_t > stdcomplex (const mha_complex_t &self)
Create a std::complex from mha_complex_t ( p. 123).

• mha_complex_t & expi (mha_complex_t &self, mha_real_t angle)
replaces the value of the given mha_complex_t ( p. 123) with exp(i∗b).

• double angle (const mha_complex_t &self)
Computes the angle of a complex number in the complex plane.

• mha_complex_t & operator+= (mha_complex_t &self, const mha_complex_t &other)
Addition of two complex numbers, overwriting the first.
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• mha_complex_t operator+ (const mha_complex_t &self, const mha_complex_←t &other)
Addition of two complex numbers, result is a temporary object.

• mha_complex_t & operator+= (mha_complex_t &self, mha_real_t other_real)
Addition of a complex and a real number, overwriting the complex.

• mha_complex_t operator+ (const mha_complex_t &self, mha_real_t other_real)
Addition of a complex and a real number, result is a temporary object.

• mha_complex_t & operator-= (mha_complex_t &self, const mha_complex_t &other)
Subtraction of two complex numbers, overwriting the first.

• mha_complex_t operator- (const mha_complex_t &self, const mha_complex_←t &other)
Subtraction of two complex numbers, result is a temporary object.

• mha_complex_t & operator-= (mha_complex_t &self, mha_real_t other_real)
Subtraction of a complex and a real number, overwriting the complex.

• mha_complex_t operator- (const mha_complex_t &self, mha_real_t other_real)
Subtraction of a complex and a real number, result is a temporary object.

• mha_complex_t & operator∗= (mha_complex_t &self, const mha_complex_t &other)
Multiplication of two complex numbers, overwriting the first.

• mha_complex_t operator∗ (const mha_complex_t &self, const mha_complex_←t &other)
Multiplication of two complex numbers, result is a temporary object.

• mha_complex_t & operator∗= (mha_complex_t &self, mha_real_t other_real)
Multiplication of a complex and a real number, overwriting the complex.

• mha_complex_t & expi (mha_complex_t &self, mha_real_t angle, mha_real_t factor)
replaces (!) the value of the given mha_complex_t ( p. 123) with a ∗ exp(i∗b)

• mha_complex_t operator∗ (const mha_complex_t &self, mha_real_t other_real)
Multiplication of a complex and a real number, result is a temporary object.

• mha_real_t abs2 (const mha_complex_t &self)
Compute the square of the absolute value of a complex value.

• mha_real_t abs (const mha_complex_t &self)
Compute the absolute value of a complex value.

• mha_complex_t & operator/= (mha_complex_t &self, mha_real_t other_real)
Division of a complex and a real number, overwriting the complex.

• mha_complex_t operator/ (const mha_complex_t &self, mha_real_t other_real)
Division of a complex and a real number, result is a temporary object.

• mha_complex_t & safe_div (mha_complex_t &self, const mha_complex_t &other,
mha_real_t eps, mha_real_t eps2)
Safe division of two complex numbers, overwriting the first.

• mha_complex_t & operator/= (mha_complex_t &self, const mha_complex_t &other)
Division of two complex numbers, overwriting the first.

• mha_complex_t operator/ (const mha_complex_t &self, const mha_complex_←t &other)
Division of two complex numbers, result is a temporary object.

• mha_complex_t operator- (const mha_complex_t &self)
Unary minus on a complex results in a negative temporary object.
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• bool operator== (const mha_complex_t &x, const mha_complex_t &y)
Compare two complex numbers for equality.

• bool operator!= (const mha_complex_t &x, const mha_complex_t &y)
Compare two complex numbers for inequality.

• void conjugate (mha_complex_t &self)
Replace (!) the value of this mha_complex_t ( p. 123) with its conjugate.

• void conjugate (mha_spec_t &self)
Replace (!) the value of this mha_spec_t ( p. 141) with its conjugate.

• mha_complex_t _conjugate (const mha_complex_t &self)
Compute the cojugate of this complex value.

• void reciprocal (mha_complex_t &self)
Replace the value of this complex with its reciprocal.

• mha_complex_t _reciprocal (const mha_complex_t &self)
compute the reciprocal of this complex value.

• void normalize (mha_complex_t &self)
Divide a complex by its absolute value, thereby normalizing it (projecting onto the unit circle).

• void normalize (mha_complex_t &self, mha_real_t margin)
Divide a complex by its absolute value, thereby normalizing it (projecting onto the unit circle),
with a safety margin.

• bool almost (const mha_complex_t &self, const mha_complex_t &other, mha_real_t
times_epsilon=1e2)
Compare two complex numbers for equality except for a small relative error.

• bool operator< (const mha_complex_t &x, const mha_complex_t &y)
Compares the absolute values of two complex numbers.

• std::ostream & operator<< (std::ostream &o, const mha_complex_t &c)
ostream operator for mha_complex_t ( p. 123)

• std::istream & operator>> (std::istream &i, mha_complex_t &c)
preliminary istream operator for mha_complex_t ( p. 123) without error checking

• mha_fft_t mha_fft_new (unsigned int n)
Create a new FFT handle.

• void mha_fft_free (mha_fft_t h)
Destroy an FFT handle.

• void mha_fft_wave2spec (mha_fft_t h, const mha_wave_t ∗in, mha_spec_t ∗out)
Tranform waveform segment into spectrum.

• void mha_fft_wave2spec (mha_fft_t h, const mha_wave_t ∗in, mha_spec_t ∗out, bool
swaps)
Tranform waveform segment into spectrum.

• void mha_fft_spec2wave (mha_fft_t h, const mha_spec_t ∗in, mha_wave_t ∗out)
Tranform spectrum into waveform segment.

• void mha_fft_spec2wave (mha_fft_t h, const mha_spec_t ∗in, mha_wave_t ∗out, unsigned int offset)
Tranform spectrum into waveform segment.

• void mha_fft_forward (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (forward).

• void mha_fft_backward (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
© 2005-2018 HörTech gGmbH, Oldenburg

5.8

mha_signal.hh File Reference

305

Complex to complex FFT (backward).

• void mha_fft_forward_scale (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (forward).

• void mha_fft_backward_scale (mha_fft_t h, mha_spec_t ∗sIn, mha_spec_t ∗sOut)
Complex to complex FFT (backward).

• void mha_fft_wave2spec_scale (mha_fft_t h, const mha_wave_t ∗in, mha_spec_←t ∗out)
Tranform waveform segment into spectrum.

• void mha_fft_spec2wave_scale (mha_fft_t h, const mha_spec_t ∗in, mha_wave_←t ∗out)
Tranform spectrum into waveform segment.

• float MHAWindow::rect (float)
Rectangular window function.

• float MHAWindow::bartlett (float)
Bartlett window function.

• float MHAWindow::hanning (float)
Hanning window function.

• float MHAWindow::hamming (float)
Hamming window function.

• float MHAWindow::blackman (float)
Blackman window function.

• template
elem_type MHASignal::kth_smallest (elem_type array[ ], unsigned n, unsigned k)
Fast search for the kth smallest element of an array.

• template
elem_type MHASignal::median (elem_type array[ ], unsigned n)
Fast median search.

• template
elem_type MHASignal::mean (const std::vector< elem_type > &data, elem_type start←_val)
Calculate average of elements in a vector.

• template
std::vector< elem_type > MHASignal::quantile (std::vector< elem_type > data, const
std::vector< elem_type > &p)
Calculate quantile of elements in a vector.

• void MHASignal::saveas_mat4 (const mha_spec_t &data, const std::string &varname,
FILE ∗fh)
Save a openMHA spectrum as a variable in a Matlab4 file.

• void MHASignal::saveas_mat4 (const mha_wave_t &data, const std::string &varname,
FILE ∗fh)
Save a openMHA waveform as a variable in a Matlab4 file.

• void MHASignal::saveas_mat4 (const std::vector< mha_real_t > &data, const std←::string &varname, FILE ∗fh)
Save a float vector as a variable in a Matlab4 file.

• void MHASignal::copy_permuted (mha_wave_t ∗dest, const mha_wave_t ∗src)
Copy contents of a waveform to a permuted waveform.
© 2005-2018 HörTech gGmbH, Oldenburg

306

CONTENTS

Variables
• unsigned long int MHASignal::signal_counter = 0
Signal counter to produce signal ID strings.

5.8.1

Detailed Description

The classes for waveform, spectrum and filterbank signals defined in this file are "intelligent"
versions of the basic waveform, spectrum and filterbank structures used in the C function calls.

5.9

mha_tablelookup.hh File Reference

Header file for table lookup classes.

Classes
• class MHATableLookup::xy_table_t
Class for interpolation with non-equidistant x values.

Namespaces
• MHATableLookup
Namespace for table lookup classes.

© 2005-2018 HörTech gGmbH, Oldenburg

Index
_conjugate
Complex arithmetics in the openMHA, 57
_reciprocal
Complex arithmetics in the openMHA, 57
∼Thread
MHA_TCP::Thread, 152
∼fourway_processor_t
PluginLoader::fourway_processor_t, 286
∼io_tcp_fwcb_t
io_tcp_fwcb_t, 104
∼io_tcp_parser_t
io_tcp_parser_t, 107
abs
Complex arithmetics in the openMHA, 57
abs2
Complex arithmetics in the openMHA, 56
ac
MHAPlugin::plugin_t, 240
AC variable, 4
ac2matrix_t
MHA_AC::ac2matrix_t, 115
accept_loop
io_tcp_t, 114
acspace2matrix_t
MHA_AC::acspace2matrix_t, 117
add
MHASignal::loop_wavefragment_t, 248
add_entry
MHATableLookup::xy_table_t, 276, 277
algo_comm_t, 88
get_entries, 91
get_error, 93
get_var, 90
get_var_float, 91
get_var_int, 91
insert_var, 88
insert_var_float, 89
insert_var_int, 89
is_var, 90
remove_ref, 90
remove_var, 89
almost
Complex arithmetics in the openMHA, 57
angle
Complex arithmetics in the openMHA, 56
aquire_mutex
mha_fifo_thread_platform_t, 138
arg

MHA_TCP::Thread, 152
assign
MHASignal::waveform_t, 273
Vector and matrix processing toolbox, 45,
46
assign_channel
MHASignal::waveform_t, 273
assign_frame
MHASignal::waveform_t, 273
async_rmslevel_t
MHASignal::async_rmslevel_t, 242
AuditoryProfile, 64
AuditoryProfile::fmap_t, 93
AuditoryProfile::parser_t, 94
AuditoryProfile::profile_t, 94
AuditoryProfile::profile_t::ear_t, 95
base_t
MHAParser::base_t, 201
MHAWindow::base_t, 279
bin2freq
Vector and matrix processing toolbox, 43
blockprocessing_polyphase_resampling_t
MHAFilter::blockprocessing_polyphase←_resampling_t, 158
bookkeeping
MHAFilter::partitioned_convolution_t, 179
bool_mon_t
MHAParser::bool_mon_t, 204
bool_t
MHAParser::bool_t, 205
buf
mha_fifo_t, 137
buf_uses_placement_new
mha_fifo_t, 137
burn
DynComp::dc_afterburn_rt_t, 96
butter_stop_ord1
MHAFilter, 70
can_read_bytes
MHA_TCP::Connection, 147
can_read_line
MHA_TCP::Connection, 147
cdata
mha_audio_t, 123
channels
Vector and matrix processing toolbox, 41
check_sound_data_type

308
io_tcp_sound_t, 111
chunkbytes_in
io_tcp_sound_t, 112
clear
mha_fifo_t, 137
Client
MHA_TCP::Client, 144
client_avg_t
MHAJack::client_avg_t, 189
colored_intensity
Vector and matrix processing toolbox, 49
comm_var_t, 95
data_type, 96
Communication between algorithms, 27
get_var_float, 29
get_var_int, 29
get_var_spectrum, 28
get_var_vfloat, 29
get_var_waveform, 29
Complex arithmetics in the openMHA, 53
_conjugate, 57
_reciprocal, 57
abs, 57
abs2, 56
almost, 57
angle, 56
expi, 56
mha_complex, 55
safe_div, 57
set, 55
complex_bandpass_t
MHAFilter::complex_bandpass_t, 160
complex_mon_t
MHAParser::complex_mon_t, 206
Concept of Variables and Data Exchange in
the openMHA, 4
configuration, 4
configuration variable, 4
connect
MHAEvents::patchbay_t, 156, 157
connect_input
MHAJack::client_t, 192
connect_output
MHAJack::client_t, 192
connect_to
MHAJack::port_t, 194
connected
io_tcp_parser_t, 110
Connection
MHA_TCP::Connection, 146
connection_loop

INDEX
io_tcp_t, 114
copy
MHASignal::spectrum_t, 264
MHASignal::waveform_t, 273
copy_channel
MHASignal::spectrum_t, 264
MHASignal::waveform_t, 273
Vector and matrix processing toolbox, 49
copy_from_at
MHASignal::waveform_t, 274
copy_permuted
MHASignal, 86
current
mha_rt_fifo_t, 141
current_input_signal_buffer_half_index
MHAFilter::partitioned_convolution_t, 179
current_output_partition_index
MHAFilter::partitioned_convolution_t, 179
data_type
comm_var_t, 96
db2lin
Vector and matrix processing toolbox, 42
dbspl2pa
Vector and matrix processing toolbox, 42
decrement
mha_fifo_thread_platform_t, 139
delay
mha_dblbuf_t, 127
delay_t
MHASignal::delay_t, 243
descriptor
mha_audio_t, 123
desired_fill_count
mha_drifter_fifo_t, 131
digits
mha_error.cpp, 291
dimension
MHASignal::matrix_t, 252
discard
MHASignal::ringbuffer_t, 258
doublebuffer_t
MHASignal::doublebuffer_t, 245
down
MHASignal::schroeder_t, 260
dupvec
Vector and matrix processing toolbox, 44
dupvec_chk
Vector and matrix processing toolbox, 44
DynComp, 64
interp1, 65
interp2, 65
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
DynComp::dc_afterburn_rt_t, 96
burn, 96
DynComp::dc_afterburn_t, 97
DynComp::dc_afterburn_vars_t, 97
DynComp::gaintable_t, 98
gaintable_t, 99
get_gain, 99, 100
update, 99
eof
MHA_TCP::Connection, 147
equal_dim
Vector and matrix processing toolbox, 45
error
mha_fifo_lw_t, 134
Error handling in the openMHA, 31
MHA_ErrorMsg, 31
MHA_assert, 32
MHA_assert_equal, 32
events
MHA_TCP::Event_Watcher, 150
expi
Complex arithmetics in the openMHA, 56
export_to
MHASignal::spectrum_t, 264
MHASignal::waveform_t, 274
expression_t, 100
Fast Fourier Transform functions, 58
mha_fft_backward, 62
mha_fft_backward_scale, 62
mha_fft_forward, 61
mha_fft_forward_scale, 62
mha_fft_free, 59
mha_fft_new, 59
mha_fft_spec2wave, 60, 61
mha_fft_spec2wave_scale, 63
mha_fft_t, 59
mha_fft_wave2spec, 59, 60
mha_fft_wave2spec_scale, 63
fftfb_t
MHAOvlFilter::fftfb_t, 196
fftfb_vars_t
MHAOvlFilter::fftfb_vars_t, 198
fftfilter_t
MHAFilter::fftfilter_t, 161
fftfilterbank_t
MHAFilter::fftfilterbank_t, 163
filter
MHAFilter::fftfilter_t, 161, 162
MHAFilter::fftfilterbank_t, 164
MHAFilter::filter_t, 166, 167
© 2005-2018 HörTech gGmbH, Oldenburg

309
MHAFilter::iir_filter_t, 169, 170
filter_partitions
MHAFilter::partitioned_convolution_t, 178
filter_t
MHAFilter::filter_t, 166
float_mon_t
MHAParser::float_mon_t, 208
float_t
MHAParser::float_t, 209
for_each
Vector and matrix processing toolbox, 41
force_remove_item
MHAParser::parser_t, 222
fragsize
io_tcp_sound_t, 113
MHAFilter::partitioned_convolution_t, 178
freq2bin
Vector and matrix processing toolbox, 43
frequency_response
MHAFilter::partitioned_convolution_t, 179
fullname
MHAParser::base_t, 202
fun_t
MHAWindow::fun_t, 281
gaintable_t
DynComp::gaintable_t, 99
gamma_flt_t
MHAFilter::gamma_flt_t, 167
get_available_space
mha_drifter_fifo_t, 130
get_comm_var
MHASignal::matrix_t, 252
get_connected
io_tcp_parser_t, 108
get_entries
algo_comm_t, 91
get_error
algo_comm_t, 93
get_fd
MHA_TCP::Connection, 147
get_fill_count
mha_drifter_fifo_t, 130
get_gain
DynComp::gaintable_t, 99, 100
get_local_address
io_tcp_parser_t, 107
get_local_port
io_tcp_parser_t, 107
get_port_capture_latency
MHAJack, 72
get_port_capture_latency_int

310
MHAJack, 72
get_port_playback_latency
MHAJack, 72
get_ports
MHAJack::client_t, 192
get_server_port_open
io_tcp_parser_t, 107
get_var
algo_comm_t, 90
get_var_float
algo_comm_t, 91
Communication between algorithms, 29
get_var_int
algo_comm_t, 91
Communication between algorithms, 29
get_var_spectrum
Communication between algorithms, 28
get_var_vfloat
Communication between algorithms, 29
get_var_waveform
Communication between algorithms, 29
getdata
MHASignal::uint_vector_t, 268
groupdelay_t
MHASignal::schroeder_t, 260
hann
MHAOvlFilter::ShapeFun, 76
header
io_tcp_sound_t, 112
hilbert_t
MHASignal::hilbert_t, 246
hton
io_tcp_sound_t, 112
hz2bark
MHAOvlFilter::FreqScaleFun, 74
hz2hz
MHAOvlFilter::FreqScaleFun, 74
hz2log
MHAOvlFilter::FreqScaleFun, 74
iir_filter_t
MHAFilter::iir_filter_t, 169
im
mha_complex_t, 124
imag
MHASignal::matrix_t, 253, 254
increment
mha_fifo_thread_platform_t, 138
index_t
MHAFilter::partitioned_convolution_t←::index_t, 180

INDEX
inner_process
MHASignal::doublebuffer_t, 245
inner_size
mha_dblbuf_t, 126
input
MHASignal::loop_wavefragment_t, 248
mha_dblbuf_t, 126
input_fifo
mha_dblbuf_t, 127
input_signal_spec
MHAFilter::partitioned_convolution_t, 179
input_signal_wave
MHAFilter::partitioned_convolution_t, 179
insert
MHA_AC::ac2matrix_t, 116
MHA_AC::acspace2matrix_t, 118
insert_item
MHAParser::parser_t, 222
insert_member
mha_parser.hh, 296
insert_var
algo_comm_t, 88
insert_var_float
algo_comm_t, 89
insert_var_int
algo_comm_t, 89
int_mon_t
MHAParser::int_mon_t, 211
int_t
MHAParser::int_t, 212
integrate
Vector and matrix processing toolbox, 45
interp
MHATableLookup::xy_table_t, 276
interp1
DynComp, 65
interp2
DynComp, 65
io
MHAJack::client_avg_t, 190
io_file_t, 100
prepare, 101
release, 101
io_lib_t, 101
prepare, 101
start, 102
io_parser_t, 102
prepare, 103
release, 103
io_tcp_fwcb_t, 103
∼io_tcp_fwcb_t, 104
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
io_tcp_fwcb_t, 104
proc_err, 105
proc_event, 105
proc_handle, 105
process, 104
set_errnos, 104
start, 104
start_event, 105
stop, 105
stop_event, 105
io_tcp_parser_t, 105
∼io_tcp_parser_t, 107
connected, 110
get_connected, 108
get_local_address, 107
get_local_port, 107
get_server_port_open, 107
io_tcp_parser_t, 107
local_address, 110
local_port, 110
peer_address, 110
peer_port, 110
server_port_open, 110
set_connected, 108
set_local_port, 107
set_new_peer, 109
set_server_port_open, 108
io_tcp_sound_t, 110
check_sound_data_type, 111
chunkbytes_in, 112
fragsize, 113
header, 112
hton, 112
io_tcp_sound_t, 111
ntoh, 112
num_inchannels, 113
prepare, 111
release, 112
s_in, 113
samplerate, 113
io_tcp_sound_t::float_union, 113
io_tcp_t, 113
accept_loop, 114
connection_loop, 114
parse, 114
prepare, 114
release, 114
start, 114
stop, 114
is_var
algo_comm_t, 90
© 2005-2018 HörTech gGmbH, Oldenburg

311
isempty
MHAFilter::transfer_function_t, 187
jack_proc_cb
MHAJack::client_t, 193
kth_smallest
MHASignal, 84
kw_t
MHAParser::kw_t, 215
last_complex_bin
MHASignal::subsample_delay_t, 266
last_config
MHAPlugin::config_t, 238
level_mode_t
MHASignal::loop_wavefragment_t, 248
limit
MHASignal, 83
MHASignal::waveform_t, 274
lin2db
Vector and matrix processing toolbox, 42
linear
MHAOvlFilter::ShapeFun, 75
local_address
io_tcp_parser_t, 110
local_port
io_tcp_parser_t, 110
lookup
MHATableLookup::xy_table_t, 276
loop_wavefragment_t
MHASignal::loop_wavefragment_t, 248
MHA_AC::ac2matrix_t, 114
ac2matrix_t, 115
insert, 116
update, 116
MHA_AC::acspace2matrix_t, 116
acspace2matrix_t, 117
insert, 118
operator=, 117
operator[], 117
update, 118
MHA_AC::double_t, 118
MHA_AC::float_t, 118
MHA_AC::int_t, 119
MHA_AC::spectrum_t, 119
spectrum_t, 120
MHA_AC::waveform_t, 120
waveform_t, 121
MHA_AC, 66
MHA_Error, 132
MHA_Error, 132

312
MHA_ErrorMsg
Error handling in the openMHA, 31
MHA_TCP::Async_Notify, 143
MHA_TCP::Client, 143
Client, 144
MHA_TCP::Connection, 144
can_read_bytes, 147
can_read_line, 147
Connection, 146
eof, 147
get_fd, 147
read_bytes, 148
read_line, 148
sysread, 146
syswrite, 146
try_write, 148
write, 148
MHA_TCP::Event_Watcher, 149
events, 150
observe, 149
wait, 149
MHA_TCP::Sockread_Event, 150
Sockread_Event, 150
MHA_TCP::Thread, 150
∼Thread, 152
arg, 152
thr_f, 152
Thread, 152
thread_arg, 152
thread_attr, 152
MHA_TCP::Timeout_Watcher, 152
MHA_TCP::Wakeup_Event, 153
Wakeup_Event, 154
MHA_TCP, 66
MHA_assert
Error handling in the openMHA, 32
MHA_assert_equal
Error handling in the openMHA, 32
MHAEvents, 67
MHAEvents::emitter_t, 156
MHAEvents::patchbay_t
connect, 156, 157
MHAEvents::patchbay_t< receiver_t >, 156
MHAFilter, 68
butter_stop_ord1, 70
o1_lp_coeffs, 69
resampling_factors, 70
sinc, 70
spec2fir, 70
MHAFilter::adapt_filter_t, 157
MHAFilter::blockprocessing_polyphase_←-

INDEX
resampling_t, 157
blockprocessing_polyphase_resampling←_t, 158
read, 159
write, 158
MHAFilter::complex_bandpass_t, 159
complex_bandpass_t, 160
MHAFilter::diff_t, 160
MHAFilter::fftfilter_t, 160
fftfilter_t, 161
filter, 161, 162
update_coeffs, 161
MHAFilter::fftfilterbank_t, 163
fftfilterbank_t, 163
filter, 164
update_coeffs, 164
MHAFilter::filter_t, 165
filter, 166, 167
filter_t, 166
MHAFilter::gamma_flt_t, 167
gamma_flt_t, 167
MHAFilter::iir_filter_t, 168
filter, 169, 170
iir_filter_t, 169
resize, 170
MHAFilter::iir_ord1_real_t, 170
MHAFilter::o1_ar_filter_t, 171
o1_ar_filter_t, 172
operator(), 172, 173
set_tau_attack, 172
set_tau_release, 172
MHAFilter::o1flt_lowpass_t, 173
o1flt_lowpass_t, 174
MHAFilter::o1flt_maxtrack_t, 174
o1flt_maxtrack_t, 175
MHAFilter::o1flt_mintrack_t, 176
MHAFilter::partitioned_convolution_t, 177
bookkeeping, 179
current_input_signal_buffer_half_index,
179
current_output_partition_index, 179
filter_partitions, 178
fragsize, 178
frequency_response, 179
input_signal_spec, 179
input_signal_wave, 179
nchannels_in, 178
nchannels_out, 178
output_partitions, 178
output_signal_spec, 179
output_signal_wave, 179
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
partitioned_convolution_t, 178
MHAFilter::partitioned_convolution_t::index←_t, 179
index_t, 180
source_channel_index, 180
target_channel_index, 180
MHAFilter::polyphase_resampling_t, 180
polyphase_resampling_t, 181
read, 182
readable_frames, 182
write, 182
MHAFilter::resampling_filter_t, 182
resampling_filter_t, 183
MHAFilter::smoothspec_t, 183
smoothspec, 184, 185
smoothspec_t, 184
spec2fir, 185
MHAFilter::transfer_function_t, 185
isempty, 187
non_empty_partitions, 186
partitions, 186
transfer_function_t, 186
MHAFilter::transfer_matrix_t, 187
MHAIOJack, 71
MHAIOJack::io_jack_t, 188
prepare, 189
reconnect_inports, 189
reconnect_outports, 189
MHAJack, 71
get_port_capture_latency, 72
get_port_capture_latency_int, 72
get_port_playback_latency, 72
MHAJack::client_avg_t, 189
client_avg_t, 189
io, 190
MHAJack::client_noncont_t, 190
MHAJack::client_t, 191
connect_input, 192
connect_output, 192
get_ports, 192
jack_proc_cb, 193
prepare, 192
prepare_impl, 192
release, 192
MHAJack::port_t, 193
connect_to, 194
mute, 194
port_t, 193, 194
read, 194
write, 194
MHAMultiSrc, 73
© 2005-2018 HörTech gGmbH, Oldenburg

313
MHAMultiSrc::base_t, 195
select_source, 195
MHAOvlFilter, 73
MHAOvlFilter::FreqScaleFun, 74
hz2bark, 74
hz2hz, 74
hz2log, 74
MHAOvlFilter::ShapeFun, 75
hann, 76
linear, 75
rect, 75
MHAOvlFilter::fftfb_t, 196
fftfb_t, 196
w, 197
MHAOvlFilter::fftfb_vars_t, 197
fftfb_vars_t, 198
MHAOvlFilter::fspacing_t, 198
MHAOvlFilter::overlap_save_filterbank_t, 199
MHAPLUGIN_CALLBACKS_PREFIX
The openMHA Plugins (programming interface), 8
MHAPLUGIN_CALLBACKS
The openMHA Plugins (programming interface), 8
MHAPLUGIN_DOCUMENTATION
The openMHA Plugins (programming interface), 9
MHAParser, 76
strreplace, 78
MHAParser::StrCnv, 79
num_brackets, 80
MHAParser::base_t, 200
base_t, 201
fullname, 202
parse, 201, 202
prereadaccess, 203
readaccess, 203
set_help, 202
set_node_id, 202
valuechanged, 202
writeaccess, 202
MHAParser::bool_mon_t, 203
bool_mon_t, 204
MHAParser::bool_t, 204
bool_t, 205
MHAParser::commit_t< receiver_t >, 205
MHAParser::complex_mon_t, 206
complex_mon_t, 206
MHAParser::complex_t, 207
MHAParser::float_mon_t, 207
float_mon_t, 208

314
MHAParser::float_t, 208
float_t, 209
MHAParser::int_mon_t, 210
int_mon_t, 211
MHAParser::int_t, 211
int_t, 212
MHAParser::keyword_list_t, 212
set_entries, 213
set_value, 213
MHAParser::kw_t, 214
kw_t, 215
set_range, 215
MHAParser::mcomplex_mon_t, 215
mcomplex_mon_t, 216
MHAParser::mcomplex_t, 216
MHAParser::mfloat_mon_t, 217
mfloat_mon_t, 218
MHAParser::mfloat_t, 218
mfloat_t, 219
MHAParser::mhapluginloader_t, 220
MHAParser::monitor_t, 220
MHAParser::parser_t, 220
force_remove_item, 222
insert_item, 222
parser_t, 222
remove_item, 222
MHAParser::range_var_t, 223
set_range, 224
MHAParser::string_mon_t, 224
string_mon_t, 224
MHAParser::string_t, 225
string_t, 225
MHAParser::variable_t, 226
setlock, 226
MHAParser::vcomplex_mon_t, 226
vcomplex_mon_t, 227
MHAParser::vcomplex_t, 227
MHAParser::vfloat_mon_t, 228
vfloat_mon_t, 229
MHAParser::vfloat_t, 229
vfloat_t, 230
MHAParser::vint_mon_t, 231
vint_mon_t, 231
MHAParser::vint_t, 232
vint_t, 233
MHAParser::vstring_mon_t, 233
vstring_mon_t, 234
MHAParser::vstring_t, 234
MHAParser::window_t, 234
MHAPlugin, 80
MHAPlugin::config_t

INDEX
last_config, 238
poll_config, 237
push_config, 238
MHAPlugin::config_t< runtime_cfg_t >, 236
MHAPlugin::plugin_t
ac, 240
plugin_t, 240
tftype, 240
MHAPlugin::plugin_t< runtime_cfg_t >, 238
MHASignal, 81
copy_permuted, 86
kth_smallest, 84
limit, 83
mean, 85
median, 84
quantile, 85
saveas_mat4, 86
MHASignal::async_rmslevel_t, 242
async_rmslevel_t, 242
peaklevel, 243
process, 243
rmslevel, 243
MHASignal::delay_t, 243
delay_t, 243
process, 244
MHASignal::delay_wave_t, 244
MHASignal::doublebuffer_t, 244
doublebuffer_t, 245
inner_process, 245
outer_process, 245
MHASignal::hilbert_t, 246
hilbert_t, 246
MHASignal::loop_wavefragment_t, 247
add, 248
input, 248
level_mode_t, 248
loop_wavefragment_t, 248
mute, 248
peak, 248
playback, 248, 249
playback_mode_t, 248
relative, 248
replace, 248
rms, 248
MHASignal::matrix_t, 249
dimension, 252
get_comm_var, 252
imag, 253, 254
matrix_t, 251, 252
operator(), 253, 254
operator=, 252
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
real, 253, 254
size, 252
MHASignal::minphase_t, 255
minphase_t, 255
operator(), 256
MHASignal::quantizer_t, 256
operator(), 256
quantizer_t, 256
MHASignal::ringbuffer_t, 257
discard, 258
ringbuffer_t, 258
value, 258
write, 259
MHASignal::schroeder_t, 259
down, 260
groupdelay_t, 260
schroeder_t, 261
sign_t, 260
up, 260
MHASignal::spectrum_t, 261
copy, 264
copy_channel, 264
export_to, 264
operator(), 263
operator[], 263
scale, 264
scale_channel, 264
spectrum_t, 263
value, 263
MHASignal::subsample_delay_t, 265
last_complex_bin, 266
process, 266
subsample_delay_t, 265
MHASignal::uint_vector_t, 266
getdata, 268
numbytes, 268
operator=, 268
uint_vector_t, 267, 268
write, 268
MHASignal::waveform_t, 268
assign, 273
assign_channel, 273
assign_frame, 273
copy, 273
copy_channel, 273
copy_from_at, 274
export_to, 274
limit, 274
operator(), 271
power, 274
powspec, 274
© 2005-2018 HörTech gGmbH, Oldenburg

315
scale, 275
scale_channel, 275
sum, 271, 272
sum_channel, 272
sumsqr, 272
value, 270, 271
waveform_t, 270
MHATableLookup, 86
MHATableLookup::xy_table_t, 275
add_entry, 276, 277
interp, 276
lookup, 276
set_xfun, 277
set_xyfun, 277
set_yfun, 277
MHAWindow, 87
MHAWindow::bartlett_t, 277
MHAWindow::base_t, 278
base_t, 279
MHAWindow::blackman_t, 279
MHAWindow::fun_t, 280
fun_t, 281
MHAWindow::hamming_t, 281
MHAWindow::hanning_t, 282
MHAWindow::rect_t, 283
MHAWindow::user_t, 284
user_t, 285
matrix_t
MHASignal::matrix_t, 251, 252
max
Vector and matrix processing toolbox, 51
max_fill_count
mha_fifo_t, 137
maxabs
Vector and matrix processing toolbox, 50,
51
maximum_reader_xruns_in_succession_←before_stop
mha_drifter_fifo_t, 131
maximum_writer_xruns_in_succession_←before_stop
mha_drifter_fifo_t, 131
mcomplex_mon_t
MHAParser::mcomplex_mon_t, 216
mean
MHASignal, 85
median
MHASignal, 84
mfloat_mon_t
MHAParser::mfloat_mon_t, 218
mfloat_t

316
MHAParser::mfloat_t, 219
mha.h, 287
mha_algo_comm.h, 289
mha_audio_descriptor_t, 122
mha_audio_t, 122
cdata, 123
descriptor, 123
rdata, 123
mha_channel_info_t, 123
mha_complex
Complex arithmetics in the openMHA, 55
mha_complex_t, 123
im, 124
re, 124
mha_dblbuf_t
delay, 127
inner_size, 126
input, 126
input_fifo, 127
mha_dblbuf_t, 125
outer_size, 126
output, 126
output_fifo, 127
process, 126
mha_dblbuf_t< FIFO >, 124
mha_defs.h, 290
mha_direction_t, 127
mha_drifter_fifo_t
desired_fill_count, 131
get_available_space, 130
get_fill_count, 130
maximum_reader_xruns_in_succession←_before_stop, 131
maximum_writer_xruns_in_succession←_before_stop, 131
mha_drifter_fifo_t, 129
minimum_fill_count, 131
read, 130
reader_started, 131
reader_xruns_in_succession, 131
starting, 130
startup_zeros, 131
stop, 130
write, 129
writer_started, 131
writer_xruns_in_succession, 131
writer_xruns_since_start, 131
mha_drifter_fifo_t< T >, 127
mha_error.cpp, 290
digits, 291
snprintf_required_length, 291

INDEX
mha_fft_backward
Fast Fourier Transform functions, 62
mha_fft_backward_scale
Fast Fourier Transform functions, 62
mha_fft_forward
Fast Fourier Transform functions, 61
mha_fft_forward_scale
Fast Fourier Transform functions, 62
mha_fft_free
Fast Fourier Transform functions, 59
mha_fft_new
Fast Fourier Transform functions, 59
mha_fft_spec2wave
Fast Fourier Transform functions, 60, 61
mha_fft_spec2wave_scale
Fast Fourier Transform functions, 63
mha_fft_t
Fast Fourier Transform functions, 59
mha_fft_wave2spec
Fast Fourier Transform functions, 59, 60
mha_fft_wave2spec_scale
Fast Fourier Transform functions, 63
mha_fifo_lw_t
error, 134
read, 134
set_error, 134
write, 134
mha_fifo_lw_t< T >, 132
mha_fifo_t
buf, 137
buf_uses_placement_new, 137
clear, 137
max_fill_count, 137
read, 136
write, 136
mha_fifo_t< T >, 135
mha_fifo_thread_guard_t, 137
mha_fifo_thread_platform_t, 137
aquire_mutex, 138
decrement, 139
increment, 138
release_mutex, 138
wait_for_decrease, 138
wait_for_increase, 138
mha_filter.hh, 291
mha_parser.hh, 293
insert_member, 296
mha_plugin.hh, 296
mha_real_t
Vector and matrix processing toolbox, 41
mha_rt_fifo_element_t
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
mha_rt_fifo_element_t, 139
mha_rt_fifo_element_t< T >, 139
mha_rt_fifo_t
current, 141
poll, 141
poll_1, 141
push, 141
mha_rt_fifo_t< T >, 140
mha_signal.hh, 297
mha_spec_t, 141
mha_tablelookup.hh, 306
mha_wave_t, 154
mhaconfig_t, 155
mhaserver_t, 241
mhaserver_t, 241
run, 241
set_announce_port, 241
min
Vector and matrix processing toolbox, 51
minimum_fill_count
mha_drifter_fifo_t, 131
minphase_t
MHASignal::minphase_t, 255
monitor variable, 4
mute
MHAJack::port_t, 194
MHASignal::loop_wavefragment_t, 248
nchannels_in
MHAFilter::partitioned_convolution_t, 178
nchannels_out
MHAFilter::partitioned_convolution_t, 178
non_empty_partitions
MHAFilter::transfer_function_t, 186
ntoh
io_tcp_sound_t, 112
num_brackets
MHAParser::StrCnv, 80
num_inchannels
io_tcp_sound_t, 113
numbytes
MHASignal::uint_vector_t, 268
o1_ar_filter_t
MHAFilter::o1_ar_filter_t, 172
o1_lp_coeffs
MHAFilter, 69
o1flt_lowpass_t
MHAFilter::o1flt_lowpass_t, 174
o1flt_maxtrack_t
MHAFilter::o1flt_maxtrack_t, 175
observe
© 2005-2018 HörTech gGmbH, Oldenburg

317
MHA_TCP::Event_Watcher, 149
operator∧ =
Vector and matrix processing toolbox, 48
operator()
MHAFilter::o1_ar_filter_t, 172, 173
MHASignal::matrix_t, 253, 254
MHASignal::minphase_t, 256
MHASignal::quantizer_t, 256
MHASignal::spectrum_t, 263
MHASignal::waveform_t, 271
operator=
MHA_AC::acspace2matrix_t, 117
MHASignal::matrix_t, 252
MHASignal::uint_vector_t, 268
operator[]
MHA_AC::acspace2matrix_t, 117
MHASignal::spectrum_t, 263
outer_process
MHASignal::doublebuffer_t, 245
outer_size
mha_dblbuf_t, 126
output
mha_dblbuf_t, 126
output_fifo
mha_dblbuf_t, 127
output_partitions
MHAFilter::partitioned_convolution_t, 178
output_signal_spec
MHAFilter::partitioned_convolution_t, 179
output_signal_wave
MHAFilter::partitioned_convolution_t, 179
pa22dbspl
Vector and matrix processing toolbox, 42
pa2dbspl
Vector and matrix processing toolbox, 42
parse
io_tcp_t, 114
MHAParser::base_t, 201, 202
parser_t
MHAParser::parser_t, 222
partitioned_convolution_t
MHAFilter::partitioned_convolution_t, 178
partitions
MHAFilter::transfer_function_t, 186
peak
MHASignal::loop_wavefragment_t, 248
peaklevel
MHASignal::async_rmslevel_t, 243
peer_address
io_tcp_parser_t, 110
peer_port

318
io_tcp_parser_t, 110
playback
MHASignal::loop_wavefragment_t, 248,
249
playback_mode_t
MHASignal::loop_wavefragment_t, 248
plugin_t
MHAPlugin::plugin_t, 240
PluginLoader::fourway_processor_t, 285
∼fourway_processor_t, 286
prepare, 287
process, 286, 287
release, 287
poll
mha_rt_fifo_t, 141
poll_1
mha_rt_fifo_t, 141
poll_config
MHAPlugin::config_t, 237
polyphase_resampling_t
MHAFilter::polyphase_resampling_t, 181
port_t
MHAJack::port_t, 193, 194
power
MHASignal::waveform_t, 274
powspec
MHASignal::waveform_t, 274
prepare
io_file_t, 101
io_lib_t, 101
io_parser_t, 103
io_tcp_sound_t, 111
io_tcp_t, 114
MHAIOJack::io_jack_t, 189
MHAJack::client_t, 192
PluginLoader::fourway_processor_t, 287
prepare_impl
MHAJack::client_t, 192
prereadaccess
MHAParser::base_t, 203
proc_err
io_tcp_fwcb_t, 105
proc_event
io_tcp_fwcb_t, 105
proc_handle
io_tcp_fwcb_t, 105
process
io_tcp_fwcb_t, 104
MHASignal::async_rmslevel_t, 243
MHASignal::delay_t, 244
MHASignal::subsample_delay_t, 266

INDEX
mha_dblbuf_t, 126
PluginLoader::fourway_processor_t, 286,
287
push
mha_rt_fifo_t, 141
push_config
MHAPlugin::config_t, 238
quantile
MHASignal, 85
quantizer_t
MHASignal::quantizer_t, 256
rad2smp
Vector and matrix processing toolbox, 44
range
Vector and matrix processing toolbox, 41
rdata
mha_audio_t, 123
re
mha_complex_t, 124
read
MHAFilter::blockprocessing_polyphase←_resampling_t, 159
MHAFilter::polyphase_resampling_t, 182
MHAJack::port_t, 194
mha_drifter_fifo_t, 130
mha_fifo_lw_t, 134
mha_fifo_t, 136
read_bytes
MHA_TCP::Connection, 148
read_line
MHA_TCP::Connection, 148
readable_frames
MHAFilter::polyphase_resampling_t, 182
readaccess
MHAParser::base_t, 203
reader_started
mha_drifter_fifo_t, 131
reader_xruns_in_succession
mha_drifter_fifo_t, 131
real
MHASignal::matrix_t, 253, 254
reconnect_inports
MHAIOJack::io_jack_t, 189
reconnect_outports
MHAIOJack::io_jack_t, 189
rect
MHAOvlFilter::ShapeFun, 75
relative
MHASignal::loop_wavefragment_t, 248
release
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
io_file_t, 101
io_parser_t, 103
io_tcp_sound_t, 112
io_tcp_t, 114
MHAJack::client_t, 192
PluginLoader::fourway_processor_t, 287
release_mutex
mha_fifo_thread_platform_t, 138
remove_item
MHAParser::parser_t, 222
remove_ref
algo_comm_t, 90
remove_var
algo_comm_t, 89
replace
MHASignal::loop_wavefragment_t, 248
resampling_factors
MHAFilter, 70
resampling_filter_t
MHAFilter::resampling_filter_t, 183
resize
MHAFilter::iir_filter_t, 170
ringbuffer_t
MHASignal::ringbuffer_t, 258
rms
MHASignal::loop_wavefragment_t, 248
rmslevel
MHASignal::async_rmslevel_t, 243
Vector and matrix processing toolbox, 49,
50
run
mhaserver_t, 241
runtime configuration, 4
s_in
io_tcp_sound_t, 113
safe_div
Complex arithmetics in the openMHA, 57
samplerate
io_tcp_sound_t, 113
saveas_mat4
MHASignal, 86
scale
MHASignal::spectrum_t, 264
MHASignal::waveform_t, 275
scale_channel
MHASignal::spectrum_t, 264
MHASignal::waveform_t, 275
schroeder_t
MHASignal::schroeder_t, 261
sec2smp
Vector and matrix processing toolbox, 43
© 2005-2018 HörTech gGmbH, Oldenburg

319
select_source
MHAMultiSrc::base_t, 195
server_port_open
io_tcp_parser_t, 110
set
Complex arithmetics in the openMHA, 55
set_announce_port
mhaserver_t, 241
set_connected
io_tcp_parser_t, 108
set_entries
MHAParser::keyword_list_t, 213
set_errnos
io_tcp_fwcb_t, 104
set_error
mha_fifo_lw_t, 134
set_help
MHAParser::base_t, 202
set_local_port
io_tcp_parser_t, 107
set_new_peer
io_tcp_parser_t, 109
set_node_id
MHAParser::base_t, 202
set_range
MHAParser::kw_t, 215
MHAParser::range_var_t, 224
set_server_port_open
io_tcp_parser_t, 108
set_tau_attack
MHAFilter::o1_ar_filter_t, 172
set_tau_release
MHAFilter::o1_ar_filter_t, 172
set_value
MHAParser::keyword_list_t, 213
set_xfun
MHATableLookup::xy_table_t, 277
set_xyfun
MHATableLookup::xy_table_t, 277
set_yfun
MHATableLookup::xy_table_t, 277
setlock
MHAParser::variable_t, 226
sign_t
MHASignal::schroeder_t, 260
sinc
MHAFilter, 70
size
MHASignal::matrix_t, 252
smoothspec
MHAFilter::smoothspec_t, 184, 185

320
smoothspec_t
MHAFilter::smoothspec_t, 184
smp2rad
Vector and matrix processing toolbox, 43
smp2sec
Vector and matrix processing toolbox, 42
snprintf_required_length
mha_error.cpp, 291
Sockread_Event
MHA_TCP::Sockread_Event, 150
source_channel_index
MHAFilter::partitioned_convolution_t←::index_t, 180
spec2fir
MHAFilter, 70
MHAFilter::smoothspec_t, 185
spectrum_t
MHA_AC::spectrum_t, 120
MHASignal::spectrum_t, 263
start
io_lib_t, 102
io_tcp_fwcb_t, 104
io_tcp_t, 114
start_event
io_tcp_fwcb_t, 105
starting
mha_drifter_fifo_t, 130
startup_zeros
mha_drifter_fifo_t, 131
std_vector_float
Vector and matrix processing toolbox, 48
std_vector_vector_complex
Vector and matrix processing toolbox, 48
std_vector_vector_float
Vector and matrix processing toolbox, 48
stop
io_tcp_fwcb_t, 105
io_tcp_t, 114
mha_drifter_fifo_t, 130
stop_event
io_tcp_fwcb_t, 105
string_mon_t
MHAParser::string_mon_t, 224
string_t
MHAParser::string_t, 225
strreplace
MHAParser, 78
subsample_delay_t
MHASignal::subsample_delay_t, 265
sum
MHASignal::waveform_t, 271, 272

INDEX
sum_channel
MHASignal::waveform_t, 272
sumsqr
MHASignal::waveform_t, 272
sumsqr_channel
Vector and matrix processing toolbox, 51
sumsqr_frame
Vector and matrix processing toolbox, 52
sysread
MHA_TCP::Connection, 146
syswrite
MHA_TCP::Connection, 146
target_channel_index
MHAFilter::partitioned_convolution_t←::index_t, 180
tftype
MHAPlugin::plugin_t, 240
The MHA Framework interface, 26
The openMHA configuration language, 33
The openMHA Plugins (programming interface), 6
MHAPLUGIN_CALLBACKS_PREFIX, 8
MHAPLUGIN_CALLBACKS, 8
MHAPLUGIN_DOCUMENTATION, 9
The openMHA Toolbox library, 34
thr_f
MHA_TCP::Thread, 152
Thread
MHA_TCP::Thread, 152
thread_arg
MHA_TCP::Thread, 152
thread_attr
MHA_TCP::Thread, 152
timeshift
Vector and matrix processing toolbox, 46
transfer_function_t
MHAFilter::transfer_function_t, 186
try_write
MHA_TCP::Connection, 148
uint_vector_t
MHASignal::uint_vector_t, 267, 268
up
MHASignal::schroeder_t, 260
update
DynComp::gaintable_t, 99
MHA_AC::ac2matrix_t, 116
MHA_AC::acspace2matrix_t, 118
update_coeffs
MHAFilter::fftfilter_t, 161
MHAFilter::fftfilterbank_t, 164
© 2005-2018 HörTech gGmbH, Oldenburg

INDEX
user_t
MHAWindow::user_t, 285

321

vfloat_t
MHAParser::vfloat_t, 230
vint_mon_t
value
MHAParser::vint_mon_t, 231
MHASignal::ringbuffer_t, 258
vint_t
MHASignal::spectrum_t, 263
MHAParser::vint_t, 233
MHASignal::waveform_t, 270, 271
vstring_mon_t
Vector and matrix processing toolbox, 46–
MHAParser::vstring_mon_t, 234
48
w
valuechanged
MHAOvlFilter::fftfb_t, 197
MHAParser::base_t, 202
wait
variable, 4
MHA_TCP::Event_Watcher, 149
variables, 4
wait_for_decrease
vcomplex_mon_t
mha_fifo_thread_platform_t, 138
MHAParser::vcomplex_mon_t, 227
wait_for_increase
Vector and matrix processing toolbox, 36
mha_fifo_thread_platform_t, 138
assign, 45, 46
Wakeup_Event
bin2freq, 43
MHA_TCP::Wakeup_Event, 154
channels, 41
waveform_t
colored_intensity, 49
MHA_AC::waveform_t, 121
copy_channel, 49
MHASignal::waveform_t, 270
db2lin, 42
write
dbspl2pa, 42
MHA_TCP::Connection, 148
dupvec, 44
MHAFilter::blockprocessing_polyphase←dupvec_chk, 44
_resampling_t, 158
equal_dim, 45
MHAFilter::polyphase_resampling_t, 182
for_each, 41
MHAJack::port_t, 194
freq2bin, 43
MHASignal::ringbuffer_t, 259
integrate, 45
MHASignal::uint_vector_t, 268
lin2db, 42
mha_drifter_fifo_t, 129
max, 51
mha_fifo_lw_t, 134
maxabs, 50, 51
mha_fifo_t, 136
mha_real_t, 41
writeaccess
min, 51
∧
MHAParser::base_t, 202
operator =, 48
writer_started
pa22dbspl, 42
mha_drifter_fifo_t, 131
pa2dbspl, 42
writer_xruns_in_succession
rad2smp, 44
mha_drifter_fifo_t, 131
range, 41
writer_xruns_since_start
rmslevel, 49, 50
mha_drifter_fifo_t, 131
sec2smp, 43
Writing openMHA Plugins. A step-by-step tusmp2rad, 43
torial, 10
smp2sec, 42
std_vector_float, 48
std_vector_vector_complex, 48
std_vector_vector_float, 48
sumsqr_channel, 51
sumsqr_frame, 52
timeshift, 46
value, 46–48
vfloat_mon_t
MHAParser::vfloat_mon_t, 229
© 2005-2018 HörTech gGmbH, Oldenburg



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