Chris@23: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@23: 
Chris@23: /*
Chris@23:     Vamp
Chris@23: 
Chris@23:     An API for audio analysis and feature extraction plugins.
Chris@23: 
Chris@23:     Centre for Digital Music, Queen Mary, University of London.
Chris@23:     This file copyright 2006 Dan Stowell.
Chris@23:   
Chris@23:     Permission is hereby granted, free of charge, to any person
Chris@23:     obtaining a copy of this software and associated documentation
Chris@23:     files (the "Software"), to deal in the Software without
Chris@23:     restriction, including without limitation the rights to use, copy,
Chris@23:     modify, merge, publish, distribute, sublicense, and/or sell copies
Chris@23:     of the Software, and to permit persons to whom the Software is
Chris@23:     furnished to do so, subject to the following conditions:
Chris@23: 
Chris@23:     The above copyright notice and this permission notice shall be
Chris@23:     included in all copies or substantial portions of the Software.
Chris@23: 
Chris@23:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
Chris@23:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
Chris@23:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
Chris@23:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
Chris@23:     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
Chris@23:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
Chris@23:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Chris@23: 
Chris@23:     Except as contained in this notice, the names of the Centre for
Chris@23:     Digital Music; Queen Mary, University of London; and Chris Cannam
Chris@23:     shall not be used in advertising or otherwise to promote the sale,
Chris@23:     use or other dealings in this Software without prior written
Chris@23:     authorization.
Chris@23: */
Chris@23: 
Chris@23: #include "AmplitudeFollower.h"
Chris@23: 
Chris@23: #include <cmath>
Chris@23: 
Chris@23: #include <string>
Chris@23: #include <vector>
Chris@23: #include <iostream>
Chris@23: 
Chris@23: using std::string;
Chris@23: using std::vector;
Chris@23: using std::cerr;
Chris@23: using std::endl;
Chris@23: 
Chris@23: /**
Chris@23:  * An implementation of SuperCollider's amplitude-follower algorithm
Chris@23:  * as a simple Vamp plugin.
Chris@23:  */
Chris@23: 
Chris@23: AmplitudeFollower::AmplitudeFollower(float inputSampleRate) :
Chris@23:     Plugin(inputSampleRate),
Chris@23:     m_stepSize(0),
Chris@23:     m_previn(0.0f),
Chris@23:     m_clampcoef(0.01f),
Chris@23:     m_relaxcoef(0.01f)
Chris@23: {
Chris@23: }
Chris@23: 
Chris@23: AmplitudeFollower::~AmplitudeFollower()
Chris@23: {
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: AmplitudeFollower::getIdentifier() const
Chris@23: {
Chris@23:     return "amplitudefollower";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: AmplitudeFollower::getName() const
Chris@23: {
Chris@23:     return "Amplitude Follower";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: AmplitudeFollower::getDescription() const
Chris@23: {
Chris@23:     return "Track the amplitude of the audio signal";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: AmplitudeFollower::getMaker() const
Chris@23: {
Chris@23:     return "Vamp SDK Example Plugins";
Chris@23: }
Chris@23: 
Chris@23: int
Chris@23: AmplitudeFollower::getPluginVersion() const
Chris@23: {
Chris@23:     return 1;
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: AmplitudeFollower::getCopyright() const
Chris@23: {
Chris@23:     return "Code copyright 2006 Dan Stowell; method from SuperCollider.  Freely redistributable (BSD license)";
Chris@23: }
Chris@23: 
Chris@23: bool
Chris@23: AmplitudeFollower::initialise(size_t channels, size_t stepSize, size_t blockSize)
Chris@23: {
Chris@23:     if (channels < getMinChannelCount() ||
Chris@23: 	channels > getMaxChannelCount()) return false;
Chris@23: 
Chris@23:     m_stepSize = std::min(stepSize, blockSize);
Chris@23: 	
Chris@23:     // Translate the coefficients 
Chris@23:     // from their "convenient" 60dB convergence-time values
Chris@23:     // to real coefficients
Chris@23:     m_clampcoef = m_clampcoef==0.0 ? 0.0 : exp(log(0.1)/(m_clampcoef * m_inputSampleRate));
Chris@23:     m_relaxcoef = m_relaxcoef==0.0 ? 0.0 : exp(log(0.1)/(m_relaxcoef * m_inputSampleRate));
Chris@23: 
Chris@23:     return true;
Chris@23: }
Chris@23: 
Chris@23: void
Chris@23: AmplitudeFollower::reset()
Chris@23: {
Chris@23:     m_previn = 0.0f;
Chris@23: }
Chris@23: 
Chris@23: AmplitudeFollower::OutputList
Chris@23: AmplitudeFollower::getOutputDescriptors() const
Chris@23: {
Chris@23:     OutputList list;
Chris@23: 
Chris@23:     OutputDescriptor sca;
Chris@23:     sca.identifier = "amplitude";
Chris@23:     sca.name = "Amplitude";
Chris@23:     sca.description = "The peak tracked amplitude for the current processing block";
Chris@23:     sca.unit = "V";
Chris@23:     sca.hasFixedBinCount = true;
Chris@23:     sca.binCount = 1;
Chris@23:     sca.hasKnownExtents = false;
Chris@23:     sca.isQuantized = false;
Chris@23:     sca.sampleType = OutputDescriptor::OneSamplePerStep;
Chris@23:     list.push_back(sca);
Chris@23: 
Chris@23:     return list;
Chris@23: }
Chris@23: 
Chris@23: AmplitudeFollower::ParameterList
Chris@23: AmplitudeFollower::getParameterDescriptors() const
Chris@23: {
Chris@23:     ParameterList list;
Chris@23: 	
Chris@23:     ParameterDescriptor att;
Chris@23:     att.identifier = "attack";
Chris@23:     att.name = "Attack time";
Chris@23:     att.description = "The 60dB convergence time for an increase in amplitude";
Chris@23:     att.unit = "s";
Chris@23:     att.minValue = 0.0f;
Chris@23:     att.maxValue = 1.f;
Chris@23:     att.defaultValue = 0.01f;
Chris@23:     att.isQuantized = false;
Chris@23:     
Chris@23:     list.push_back(att);
Chris@23:     
Chris@23:     ParameterDescriptor dec;
Chris@23:     dec.identifier = "release";
Chris@23:     dec.name = "Release time";
Chris@23:     dec.description = "The 60dB convergence time for a decrease in amplitude";
Chris@23:     dec.unit = "s";
Chris@23:     dec.minValue = 0.0f;
Chris@23:     dec.maxValue = 1.f;
Chris@23:     dec.defaultValue = 0.01f;
Chris@23:     dec.isQuantized = false;
Chris@23:     
Chris@23:     list.push_back(dec);
Chris@23:     
Chris@23:     return list;
Chris@23: }
Chris@23: 
Chris@23: void AmplitudeFollower::setParameter(std::string paramid, float newval)
Chris@23: {
Chris@23:     if (paramid == "attack") {
Chris@23:         m_clampcoef = newval;
Chris@23:     } else if (paramid == "release") {
Chris@23:         m_relaxcoef = newval;
Chris@23:     }
Chris@23: }
Chris@23: 
Chris@23: float AmplitudeFollower::getParameter(std::string paramid) const
Chris@23: {
Chris@23:     if (paramid == "attack") {
Chris@23:         return m_clampcoef;
Chris@23:     } else if (paramid == "release") {
Chris@23:         return m_relaxcoef;
Chris@23:     }
Chris@23: 
Chris@23:     return 0.0f;
Chris@23: }
Chris@23: 
Chris@23: AmplitudeFollower::FeatureSet
Chris@23: AmplitudeFollower::process(const float *const *inputBuffers,
Chris@23:                            Vamp::RealTime timestamp)
Chris@23: {
Chris@23:     if (m_stepSize == 0) {
Chris@23: 	cerr << "ERROR: AmplitudeFollower::process: "
Chris@23: 	     << "AmplitudeFollower has not been initialised"
Chris@23: 	     << endl;
Chris@23: 	return FeatureSet();
Chris@23:     }
Chris@23: 
Chris@23:     float previn = m_previn;
Chris@23: 
Chris@23:     FeatureSet returnFeatures;
Chris@23: 	
Chris@23:     float val;
Chris@23:     float peak = 0.0f;
Chris@23: 
Chris@23:     for (size_t i = 0; i < m_stepSize; ++i) {
Chris@23: 
Chris@23:         val = fabs(inputBuffers[0][i]);
Chris@23: 		
Chris@23:         if (val < previn) {
Chris@23:             val = val + (previn - val) * m_relaxcoef;
Chris@23:         } else {
Chris@23:             val = val + (previn - val) * m_clampcoef;
Chris@23:         }
Chris@23: 
Chris@23:         if (val > peak) peak = val;
Chris@23:         previn = val;
Chris@23:     }
Chris@23: 
Chris@23:     m_previn = previn;
Chris@23: 
Chris@23:     // Now store the "feature" (peak amp) for this sample
Chris@23:     Feature feature;
Chris@23:     feature.hasTimestamp = false;
Chris@23:     feature.values.push_back(peak);
Chris@23:     returnFeatures[0].push_back(feature);
Chris@23: 
Chris@23:     return returnFeatures;
Chris@23: }
Chris@23: 
Chris@23: AmplitudeFollower::FeatureSet
Chris@23: AmplitudeFollower::getRemainingFeatures()
Chris@23: {
Chris@23:     return FeatureSet();
Chris@23: }
Chris@23: