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:     Copyright 2006 Chris Cannam.
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 "ZeroCrossing.h"
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: #include <cmath>
Chris@23: 
Chris@23: ZeroCrossing::ZeroCrossing(float inputSampleRate) :
Chris@23:     Plugin(inputSampleRate),
Chris@23:     m_stepSize(0),
Chris@23:     m_previousSample(0.0f)
Chris@23: {
Chris@23: }
Chris@23: 
Chris@23: ZeroCrossing::~ZeroCrossing()
Chris@23: {
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: ZeroCrossing::getIdentifier() const
Chris@23: {
Chris@23:     return "zerocrossing";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: ZeroCrossing::getName() const
Chris@23: {
Chris@23:     return "Zero Crossings";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: ZeroCrossing::getDescription() const
Chris@23: {
Chris@23:     return "Detect and count zero crossing points";
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: ZeroCrossing::getMaker() const
Chris@23: {
Chris@23:     return "Vamp SDK Example Plugins";
Chris@23: }
Chris@23: 
Chris@23: int
Chris@23: ZeroCrossing::getPluginVersion() const
Chris@23: {
Chris@23:     return 2;
Chris@23: }
Chris@23: 
Chris@23: string
Chris@23: ZeroCrossing::getCopyright() const
Chris@23: {
Chris@23:     return "Freely redistributable (BSD license)";
Chris@23: }
Chris@23: 
Chris@23: bool
Chris@23: ZeroCrossing::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:     return true;
Chris@23: }
Chris@23: 
Chris@23: void
Chris@23: ZeroCrossing::reset()
Chris@23: {
Chris@23:     m_previousSample = 0.0f;
Chris@23: }
Chris@23: 
Chris@23: ZeroCrossing::OutputList
Chris@23: ZeroCrossing::getOutputDescriptors() const
Chris@23: {
Chris@23:     OutputList list;
Chris@23: 
Chris@23:     OutputDescriptor zc;
Chris@23:     zc.identifier = "counts";
Chris@23:     zc.name = "Zero Crossing Counts";
Chris@23:     zc.description = "The number of zero crossing points per processing block";
Chris@23:     zc.unit = "crossings";
Chris@23:     zc.hasFixedBinCount = true;
Chris@23:     zc.binCount = 1;
Chris@23:     zc.hasKnownExtents = false;
Chris@23:     zc.isQuantized = true;
Chris@23:     zc.quantizeStep = 1.0;
Chris@23:     zc.sampleType = OutputDescriptor::OneSamplePerStep;
Chris@23:     list.push_back(zc);
Chris@23: 
Chris@23:     zc.identifier = "zerocrossings";
Chris@23:     zc.name = "Zero Crossings";
Chris@23:     zc.description = "The locations of zero crossing points";
Chris@23:     zc.unit = "";
Chris@23:     zc.hasFixedBinCount = true;
Chris@23:     zc.binCount = 0;
Chris@23:     zc.sampleType = OutputDescriptor::VariableSampleRate;
Chris@23:     zc.sampleRate = m_inputSampleRate;
Chris@23:     list.push_back(zc);
Chris@23: 
Chris@23:     return list;
Chris@23: }
Chris@23: 
Chris@23: ZeroCrossing::FeatureSet
Chris@23: ZeroCrossing::process(const float *const *inputBuffers,
Chris@23:                       Vamp::RealTime timestamp)
Chris@23: {
Chris@23:     if (m_stepSize == 0) {
Chris@23: 	cerr << "ERROR: ZeroCrossing::process: "
Chris@23: 	     << "ZeroCrossing has not been initialised"
Chris@23: 	     << endl;
Chris@23: 	return FeatureSet();
Chris@23:     }
Chris@23: 
Chris@23:     float prev = m_previousSample;
Chris@23:     size_t count = 0;
Chris@23: 
Chris@23:     FeatureSet returnFeatures;
Chris@23: 
Chris@23:     for (size_t i = 0; i < m_stepSize; ++i) {
Chris@23: 
Chris@23: 	float sample = inputBuffers[0][i];
Chris@23: 	bool crossing = false;
Chris@23: 
Chris@23: 	if (sample <= 0.0) {
Chris@23: 	    if (prev > 0.0) crossing = true;
Chris@23: 	} else if (sample > 0.0) {
Chris@23: 	    if (prev <= 0.0) crossing = true;
Chris@23: 	}
Chris@23: 
Chris@23: 	if (crossing) {
Chris@23: 	    ++count; 
Chris@23: 	    Feature feature;
Chris@23: 	    feature.hasTimestamp = true;
Chris@23: 	    feature.timestamp = timestamp +
Chris@23: 		Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate);
Chris@23: 	    returnFeatures[1].push_back(feature);
Chris@23: 	}
Chris@23: 
Chris@23: 	prev = sample;
Chris@23:     }
Chris@23: 
Chris@23:     m_previousSample = prev;
Chris@23: 
Chris@23:     Feature feature;
Chris@23:     feature.hasTimestamp = false;
Chris@23:     feature.values.push_back(float(count));
Chris@23: 
Chris@23:     returnFeatures[0].push_back(feature);
Chris@23:     return returnFeatures;
Chris@23: }
Chris@23: 
Chris@23: ZeroCrossing::FeatureSet
Chris@23: ZeroCrossing::getRemainingFeatures()
Chris@23: {
Chris@23:     return FeatureSet();
Chris@23: }
Chris@23: