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Diffstat (limited to 'libs/vamp-plugins/ZeroCrossing.cpp')
| -rw-r--r-- | libs/vamp-plugins/ZeroCrossing.cpp | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/libs/vamp-plugins/ZeroCrossing.cpp b/libs/vamp-plugins/ZeroCrossing.cpp new file mode 100644 index 0000000000..4b678e3f8f --- /dev/null +++ b/libs/vamp-plugins/ZeroCrossing.cpp @@ -0,0 +1,194 @@ +/* -*- 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. + Copyright 2006 Chris Cannam. + + 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 + ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF + 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, + use or other dealings in this Software without prior written + authorization. +*/ + +#include "ZeroCrossing.h" + +using std::string; +using std::vector; +using std::cerr; +using std::endl; + + +ZeroCrossing::ZeroCrossing(float inputSampleRate) : + Plugin(inputSampleRate), + m_stepSize(0), + m_previousSample(0.0f) +{ +} + +ZeroCrossing::~ZeroCrossing() +{ +} + +string +ZeroCrossing::getIdentifier() const +{ + return "zerocrossing"; +} + +string +ZeroCrossing::getName() const +{ + return "Zero Crossings"; +} + +string +ZeroCrossing::getDescription() const +{ + return "Detect and count zero crossing points"; +} + +string +ZeroCrossing::getMaker() const +{ + return "Vamp SDK Example Plugins"; +} + +int +ZeroCrossing::getPluginVersion() const +{ + return 2; +} + +string +ZeroCrossing::getCopyright() const +{ + return "Freely redistributable (BSD license)"; +} + +bool +ZeroCrossing::initialise(size_t channels, size_t stepSize, size_t blockSize) +{ + if (channels < getMinChannelCount() || + channels > getMaxChannelCount()) return false; + + m_stepSize = std::min(stepSize, blockSize); + + return true; +} + +void +ZeroCrossing::reset() +{ + m_previousSample = 0.0f; +} + +ZeroCrossing::OutputList +ZeroCrossing::getOutputDescriptors() const +{ + OutputList list; + + OutputDescriptor zc; + zc.identifier = "counts"; + zc.name = "Zero Crossing Counts"; + zc.description = "The number of zero crossing points per processing block"; + zc.unit = "crossings"; + zc.hasFixedBinCount = true; + zc.binCount = 1; + zc.hasKnownExtents = false; + zc.isQuantized = true; + zc.quantizeStep = 1.0; + zc.sampleType = OutputDescriptor::OneSamplePerStep; + list.push_back(zc); + + zc.identifier = "zerocrossings"; + zc.name = "Zero Crossings"; + zc.description = "The locations of zero crossing points"; + zc.unit = ""; + zc.hasFixedBinCount = true; + zc.binCount = 0; + zc.sampleType = OutputDescriptor::VariableSampleRate; + zc.sampleRate = m_inputSampleRate; + list.push_back(zc); + + return list; +} + +ZeroCrossing::FeatureSet +ZeroCrossing::process(const float *const *inputBuffers, + Vamp::RealTime timestamp) +{ + if (m_stepSize == 0) { + cerr << "ERROR: ZeroCrossing::process: " + << "ZeroCrossing has not been initialised" + << endl; + return FeatureSet(); + } + + float prev = m_previousSample; + size_t count = 0; + + FeatureSet returnFeatures; + + for (size_t i = 0; i < m_stepSize; ++i) { + + float sample = inputBuffers[0][i]; + bool crossing = false; + + if (sample <= 0.0) { + if (prev > 0.0) crossing = true; + } else if (sample > 0.0) { + if (prev <= 0.0) crossing = true; + } + + if (crossing) { + ++count; + Feature feature; + feature.hasTimestamp = true; + feature.timestamp = timestamp + + Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate); + returnFeatures[1].push_back(feature); + } + + prev = sample; + } + + m_previousSample = prev; + + Feature feature; + feature.hasTimestamp = false; + feature.values.push_back(count); + + returnFeatures[0].push_back(feature); + return returnFeatures; +} + +ZeroCrossing::FeatureSet +ZeroCrossing::getRemainingFeatures() +{ + return FeatureSet(); +} + |