cannam@97: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@97: 
cannam@97: /*
cannam@97:     Vamp
cannam@97: 
cannam@97:     An API for audio analysis and feature extraction plugins.
cannam@97: 
cannam@97:     Centre for Digital Music, Queen Mary, University of London.
cannam@97:     Copyright 2006 Chris Cannam.
cannam@97:   
cannam@97:     Permission is hereby granted, free of charge, to any person
cannam@97:     obtaining a copy of this software and associated documentation
cannam@97:     files (the "Software"), to deal in the Software without
cannam@97:     restriction, including without limitation the rights to use, copy,
cannam@97:     modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@97:     of the Software, and to permit persons to whom the Software is
cannam@97:     furnished to do so, subject to the following conditions:
cannam@97: 
cannam@97:     The above copyright notice and this permission notice shall be
cannam@97:     included in all copies or substantial portions of the Software.
cannam@97: 
cannam@97:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@97:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@97:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@97:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@97:     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@97:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@97:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@97: 
cannam@97:     Except as contained in this notice, the names of the Centre for
cannam@97:     Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@97:     shall not be used in advertising or otherwise to promote the sale,
cannam@97:     use or other dealings in this Software without prior written
cannam@97:     authorization.
cannam@97: */
cannam@97: 
cannam@97: #include "ZeroCrossing.h"
cannam@97: 
cannam@97: using std::string;
cannam@97: using std::vector;
cannam@97: using std::cerr;
cannam@97: using std::endl;
cannam@97: 
cannam@97: #include <cmath>
cannam@97: 
cannam@97: ZeroCrossing::ZeroCrossing(float inputSampleRate) :
cannam@97:     Plugin(inputSampleRate),
cannam@97:     m_stepSize(0),
cannam@97:     m_previousSample(0.0f)
cannam@97: {
cannam@97: }
cannam@97: 
cannam@97: ZeroCrossing::~ZeroCrossing()
cannam@97: {
cannam@97: }
cannam@97: 
cannam@97: string
cannam@97: ZeroCrossing::getIdentifier() const
cannam@97: {
cannam@97:     return "zerocrossing";
cannam@97: }
cannam@97: 
cannam@97: string
cannam@97: ZeroCrossing::getName() const
cannam@97: {
cannam@97:     return "Zero Crossings";
cannam@97: }
cannam@97: 
cannam@97: string
cannam@97: ZeroCrossing::getDescription() const
cannam@97: {
cannam@97:     return "Detect and count zero crossing points";
cannam@97: }
cannam@97: 
cannam@97: string
cannam@97: ZeroCrossing::getMaker() const
cannam@97: {
cannam@97:     return "Vamp SDK Example Plugins";
cannam@97: }
cannam@97: 
cannam@97: int
cannam@97: ZeroCrossing::getPluginVersion() const
cannam@97: {
cannam@97:     return 2;
cannam@97: }
cannam@97: 
cannam@97: string
cannam@97: ZeroCrossing::getCopyright() const
cannam@97: {
cannam@97:     return "Freely redistributable (BSD license)";
cannam@97: }
cannam@97: 
cannam@97: bool
cannam@97: ZeroCrossing::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@97: {
cannam@97:     if (channels < getMinChannelCount() ||
cannam@97: 	channels > getMaxChannelCount()) return false;
cannam@97: 
cannam@97:     m_stepSize = std::min(stepSize, blockSize);
cannam@97: 
cannam@97:     return true;
cannam@97: }
cannam@97: 
cannam@97: void
cannam@97: ZeroCrossing::reset()
cannam@97: {
cannam@97:     m_previousSample = 0.0f;
cannam@97: }
cannam@97: 
cannam@97: ZeroCrossing::OutputList
cannam@97: ZeroCrossing::getOutputDescriptors() const
cannam@97: {
cannam@97:     OutputList list;
cannam@97: 
cannam@97:     OutputDescriptor zc;
cannam@97:     zc.identifier = "counts";
cannam@97:     zc.name = "Zero Crossing Counts";
cannam@97:     zc.description = "The number of zero crossing points per processing block";
cannam@97:     zc.unit = "crossings";
cannam@97:     zc.hasFixedBinCount = true;
cannam@97:     zc.binCount = 1;
cannam@97:     zc.hasKnownExtents = false;
cannam@97:     zc.isQuantized = true;
cannam@97:     zc.quantizeStep = 1.0;
cannam@97:     zc.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@97:     list.push_back(zc);
cannam@97: 
cannam@97:     zc.identifier = "zerocrossings";
cannam@97:     zc.name = "Zero Crossings";
cannam@97:     zc.description = "The locations of zero crossing points";
cannam@97:     zc.unit = "";
cannam@97:     zc.hasFixedBinCount = true;
cannam@97:     zc.binCount = 0;
cannam@97:     zc.sampleType = OutputDescriptor::VariableSampleRate;
cannam@97:     zc.sampleRate = m_inputSampleRate;
cannam@97:     list.push_back(zc);
cannam@97: 
cannam@97:     return list;
cannam@97: }
cannam@97: 
cannam@97: ZeroCrossing::FeatureSet
cannam@97: ZeroCrossing::process(const float *const *inputBuffers,
cannam@97:                       Vamp::RealTime timestamp)
cannam@97: {
cannam@97:     if (m_stepSize == 0) {
cannam@97: 	cerr << "ERROR: ZeroCrossing::process: "
cannam@97: 	     << "ZeroCrossing has not been initialised"
cannam@97: 	     << endl;
cannam@97: 	return FeatureSet();
cannam@97:     }
cannam@97: 
cannam@97:     float prev = m_previousSample;
cannam@97:     size_t count = 0;
cannam@97: 
cannam@97:     FeatureSet returnFeatures;
cannam@97: 
cannam@97:     for (size_t i = 0; i < m_stepSize; ++i) {
cannam@97: 
cannam@97: 	float sample = inputBuffers[0][i];
cannam@97: 	bool crossing = false;
cannam@97: 
cannam@97: 	if (sample <= 0.0) {
cannam@97: 	    if (prev > 0.0) crossing = true;
cannam@97: 	} else if (sample > 0.0) {
cannam@97: 	    if (prev <= 0.0) crossing = true;
cannam@97: 	}
cannam@97: 
cannam@97: 	if (crossing) {
cannam@97: 	    ++count; 
cannam@97: 	    Feature feature;
cannam@97: 	    feature.hasTimestamp = true;
cannam@97: 	    feature.timestamp = timestamp +
cannam@97: 		Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate);
cannam@97: 	    returnFeatures[1].push_back(feature);
cannam@97: 	}
cannam@97: 
cannam@97: 	prev = sample;
cannam@97:     }
cannam@97: 
cannam@97:     m_previousSample = prev;
cannam@97: 
cannam@97:     Feature feature;
cannam@97:     feature.hasTimestamp = false;
cannam@97:     feature.values.push_back(float(count));
cannam@97: 
cannam@97:     returnFeatures[0].push_back(feature);
cannam@97:     return returnFeatures;
cannam@97: }
cannam@97: 
cannam@97: ZeroCrossing::FeatureSet
cannam@97: ZeroCrossing::getRemainingFeatures()
cannam@97: {
cannam@97:     return FeatureSet();
cannam@97: }
cannam@97: