AmplitudeFollower.cpp
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
/*
Vamp
An API for audio analysis and feature extraction plugins.
Centre for Digital Music, Queen Mary, University of London.
This file copyright 2006 Dan Stowell.
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
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CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the names of the Centre for
Digital Music; Queen Mary, University of London; and Chris Cannam
shall not be used in advertising or otherwise to promote the sale,
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*/
#include "AmplitudeFollower.h"
#include <cmath>
#include <string>
#include <vector>
#include <iostream>
using std::string;
using std::vector;
using std::cerr;
using std::endl;
AmplitudeFollower::AmplitudeFollower(float inputSampleRate) :
Plugin(inputSampleRate),
m_stepSize(0),
m_previn(0.0f),
m_clampcoef(0.01f),
m_relaxcoef(0.01f)
{
}
AmplitudeFollower::~AmplitudeFollower()
{
}
string
AmplitudeFollower::getIdentifier() const
{
return "amplitudefollower";
}
string
AmplitudeFollower::getName() const
{
return "Amplitude Follower";
}
string
AmplitudeFollower::getDescription() const
{
return "Track the amplitude of the audio signal";
}
string
AmplitudeFollower::getMaker() const
{
return "Vamp SDK Example Plugins";
}
int
AmplitudeFollower::getPluginVersion() const
{
return 1;
}
string
AmplitudeFollower::getCopyright() const
{
return "Code copyright 2006 Dan Stowell; method from SuperCollider. Freely redistributable (BSD license)";
}
bool
AmplitudeFollower::initialise(size_t channels, size_t stepSize, size_t blockSize)
{
if (channels < getMinChannelCount() ||
channels > getMaxChannelCount()) return false;
m_stepSize = std::min(stepSize, blockSize);
// Translate the coefficients
// from their "convenient" 60dB convergence-time values
// to real coefficients
m_clampcoef = m_clampcoef==0.0 ? 0.0 : exp(log(0.1)/(m_clampcoef * m_inputSampleRate));
m_relaxcoef = m_relaxcoef==0.0 ? 0.0 : exp(log(0.1)/(m_relaxcoef * m_inputSampleRate));
return true;
}
void
AmplitudeFollower::reset()
{
m_previn = 0.0f;
}
AmplitudeFollower::OutputList
AmplitudeFollower::getOutputDescriptors() const
{
OutputList list;
OutputDescriptor sca;
sca.identifier = "amplitude";
sca.name = "Amplitude";
sca.description = "The peak tracked amplitude for the current processing block";
sca.unit = "V";
sca.hasFixedBinCount = true;
sca.binCount = 1;
sca.hasKnownExtents = false;
sca.isQuantized = false;
sca.sampleType = OutputDescriptor::OneSamplePerStep;
list.push_back(sca);
return list;
}
AmplitudeFollower::ParameterList
AmplitudeFollower::getParameterDescriptors() const
{
ParameterList list;
ParameterDescriptor att;
att.identifier = "attack";
att.name = "Attack time";
att.description = "The 60dB convergence time for an increase in amplitude";
att.unit = "s";
att.minValue = 0.0f;
att.maxValue = 1.f;
att.defaultValue = 0.01f;
att.isQuantized = false;
list.push_back(att);
ParameterDescriptor dec;
dec.identifier = "release";
dec.name = "Release time";
dec.description = "The 60dB convergence time for a decrease in amplitude";
dec.unit = "s";
dec.minValue = 0.0f;
dec.maxValue = 1.f;
dec.defaultValue = 0.01f;
dec.isQuantized = false;
list.push_back(dec);
return list;
}
void AmplitudeFollower::setParameter(std::string paramid, float newval)
{
if (paramid == "attack") {
m_clampcoef = newval;
} else if (paramid == "release") {
m_relaxcoef = newval;
}
}
float AmplitudeFollower::getParameter(std::string paramid) const
{
if (paramid == "attack") {
return m_clampcoef;
} else if (paramid == "release") {
return m_relaxcoef;
}
return 0.0f;
}
AmplitudeFollower::FeatureSet
AmplitudeFollower::process(const float *const *inputBuffers,
Vamp::RealTime timestamp)
{
if (m_stepSize == 0) {
cerr << "ERROR: AmplitudeFollower::process: "
<< "AmplitudeFollower has not been initialised"
<< endl;
return FeatureSet();
}
float previn = m_previn;
FeatureSet returnFeatures;
float val;
float peak = 0.0f;
for (size_t i = 0; i < m_stepSize; ++i) {
val = fabs(inputBuffers[0][i]);
if (val < previn) {
val = val + (previn - val) * m_relaxcoef;
} else {
val = val + (previn - val) * m_clampcoef;
}
if (val > peak) peak = val;
previn = val;
}
m_previn = previn;
// Now store the "feature" (peak amp) for this sample
Feature feature;
feature.hasTimestamp = false;
feature.values.push_back(peak);
returnFeatures[0].push_back(feature);
return returnFeatures;
}
AmplitudeFollower::FeatureSet
AmplitudeFollower::getRemainingFeatures()
{
return FeatureSet();
}
Vamp::Plugin::OutputList
std::vector< OutputDescriptor > OutputList
Definition: vamp-sdk/Plugin.h:327
AmplitudeFollower::initialise
bool initialise(size_t channels, size_t stepSize, size_t blockSize)
Initialise a plugin to prepare it for use with the given number of input channels, step size (window increment, in sample frames) and block size (window size, in sample frames).
Definition: AmplitudeFollower.cpp:105
Vamp::Plugin::OutputDescriptor
Definition: vamp-sdk/Plugin.h:206
AmplitudeFollower::getOutputDescriptors
OutputList getOutputDescriptors() const
Get the outputs of this plugin.
Definition: AmplitudeFollower.cpp:128
AmplitudeFollower::AmplitudeFollower
AmplitudeFollower(float inputSampleRate)
An implementation of SuperCollider's amplitude-follower algorithm as a simple Vamp plugin...
Definition: AmplitudeFollower.cpp:55
Vamp::Plugin::OutputDescriptor::hasFixedBinCount
bool hasFixedBinCount
True if the output has the same number of values per sample for every output sample.
Definition: vamp-sdk/Plugin.h:239
Vamp::Plugin::Feature::values
std::vector< float > values
Results for a single sample of this feature.
Definition: vamp-sdk/Plugin.h:374
Vamp::Plugin::FeatureSet
std::map< int, FeatureList > FeatureSet
Definition: vamp-sdk/Plugin.h:387
Vamp::PluginBase::ParameterDescriptor::identifier
std::string identifier
The name of the parameter, in computer-usable form.
Definition: vamp-sdk/PluginBase.h:133
Vamp::Plugin::OutputDescriptor::description
std::string description
A human-readable short text describing the output.
Definition: vamp-sdk/Plugin.h:227
Vamp::Plugin::OutputDescriptor::identifier
std::string identifier
The name of the output, in computer-usable form.
Definition: vamp-sdk/Plugin.h:214
AmplitudeFollower::getRemainingFeatures
FeatureSet getRemainingFeatures()
After all blocks have been processed, calculate and return any remaining features derived from the co...
Definition: AmplitudeFollower.cpp:243
Vamp::PluginBase::ParameterDescriptor::name
std::string name
The human-readable name of the parameter.
Definition: vamp-sdk/PluginBase.h:138
Vamp::Plugin::Feature
Definition: vamp-sdk/Plugin.h:336
Vamp::Plugin::m_inputSampleRate
float m_inputSampleRate
Definition: vamp-sdk/Plugin.h:436
AmplitudeFollower::getMaker
std::string getMaker() const
Get the name of the author or vendor of the plugin in human-readable form.
Definition: AmplitudeFollower.cpp:87
Vamp::PluginBase::ParameterDescriptor::minValue
float minValue
The minimum value of the parameter.
Definition: vamp-sdk/PluginBase.h:154
Vamp::PluginBase::ParameterDescriptor::unit
std::string unit
The unit of the parameter, in human-readable form.
Definition: vamp-sdk/PluginBase.h:149
Vamp::Plugin::OutputDescriptor::unit
std::string unit
The unit of the output, in human-readable form.
Definition: vamp-sdk/Plugin.h:232
Vamp::Plugin::OutputDescriptor::name
std::string name
The human-readable name of the output.
Definition: vamp-sdk/Plugin.h:220
Vamp::RealTime
RealTime represents time values to nanosecond precision with accurate arithmetic and frame-rate conve...
Definition: vamp-sdk/RealTime.h:66
Vamp::Plugin::Feature::hasTimestamp
bool hasTimestamp
True if an output feature has its own timestamp.
Definition: vamp-sdk/Plugin.h:344
AmplitudeFollower.h
Vamp::PluginBase::ParameterDescriptor::description
std::string description
A human-readable short text describing the parameter.
Definition: vamp-sdk/PluginBase.h:144
Vamp::PluginBase::ParameterDescriptor
Definition: vamp-sdk/PluginBase.h:126
Vamp::PluginBase::ParameterDescriptor::maxValue
float maxValue
The maximum value of the parameter.
Definition: vamp-sdk/PluginBase.h:159
AmplitudeFollower::getIdentifier
std::string getIdentifier() const
Get the computer-usable name of the plugin.
Definition: AmplitudeFollower.cpp:69
AmplitudeFollower::getDescription
std::string getDescription() const
Get a human-readable description for the plugin, typically a line of text that may optionally be disp...
Definition: AmplitudeFollower.cpp:81
AmplitudeFollower::reset
void reset()
Reset the plugin after use, to prepare it for another clean run.
Definition: AmplitudeFollower.cpp:122
AmplitudeFollower::m_stepSize
size_t m_stepSize
Definition: AmplitudeFollower.h:77
AmplitudeFollower::getName
std::string getName() const
Get a human-readable name or title of the plugin.
Definition: AmplitudeFollower.cpp:75
AmplitudeFollower::m_previn
float m_previn
Definition: AmplitudeFollower.h:78
AmplitudeFollower::getCopyright
std::string getCopyright() const
Get the copyright statement or licensing summary for the plugin.
Definition: AmplitudeFollower.cpp:99
AmplitudeFollower::getParameterDescriptors
ParameterList getParameterDescriptors() const
Get the controllable parameters of this plugin.
Definition: AmplitudeFollower.cpp:148
Vamp::Plugin::OutputDescriptor::OneSamplePerStep
Results from each process() align with that call's block start.
Definition: vamp-sdk/Plugin.h:290
Vamp::Plugin::getMaxChannelCount
virtual size_t getMaxChannelCount() const
Get the maximum supported number of input channels.
Definition: vamp-sdk/Plugin.h:204
Vamp::Plugin::OutputDescriptor::binCount
size_t binCount
The number of values per result of the output.
Definition: vamp-sdk/Plugin.h:247
AmplitudeFollower::getPluginVersion
int getPluginVersion() const
Get the version number of the plugin.
Definition: AmplitudeFollower.cpp:93
AmplitudeFollower::m_clampcoef
float m_clampcoef
Definition: AmplitudeFollower.h:79
Vamp::Plugin::OutputDescriptor::isQuantized
bool isQuantized
True if the output values are quantized to a particular resolution.
Definition: vamp-sdk/Plugin.h:278
AmplitudeFollower::m_relaxcoef
float m_relaxcoef
Definition: AmplitudeFollower.h:80
Vamp::PluginBase::ParameterDescriptor::defaultValue
float defaultValue
The default value of the parameter.
Definition: vamp-sdk/PluginBase.h:167
AmplitudeFollower::setParameter
void setParameter(std::string paramid, float newval)
Set a named parameter.
Definition: AmplitudeFollower.cpp:179
Vamp::Plugin::getMinChannelCount
virtual size_t getMinChannelCount() const
Get the minimum supported number of input channels.
Definition: vamp-sdk/Plugin.h:199
AmplitudeFollower::process
FeatureSet process(const float *const *inputBuffers, Vamp::RealTime timestamp)
Process a single block of input data.
Definition: AmplitudeFollower.cpp:200
Vamp::PluginBase::ParameterDescriptor::isQuantized
bool isQuantized
True if the parameter values are quantized to a particular resolution.
Definition: vamp-sdk/PluginBase.h:173
AmplitudeFollower::~AmplitudeFollower
virtual ~AmplitudeFollower()
Definition: AmplitudeFollower.cpp:64
Vamp::Plugin::OutputDescriptor::sampleType
SampleType sampleType
Positioning in time of the output results.
Definition: vamp-sdk/Plugin.h:302
AmplitudeFollower::getParameter
float getParameter(std::string paramid) const
Get the value of a named parameter.
Definition: AmplitudeFollower.cpp:188
Vamp::Plugin::OutputDescriptor::hasKnownExtents
bool hasKnownExtents
True if the results in each output bin fall within a fixed numeric range (minimum and maximum values)...
Definition: vamp-sdk/Plugin.h:260
Vamp::PluginBase::ParameterList
std::vector< ParameterDescriptor > ParameterList
Definition: vamp-sdk/PluginBase.h:199