cannam@0: cannam@0: cannam@0: VampPluginSDK: ZeroCrossing.cpp Source File cannam@0: cannam@0: cannam@0: cannam@0: cannam@0: cannam@0: cannam@0:

ZeroCrossing.cpp

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00001 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@0: 00002 
cannam@0: 00003 /*
cannam@0: 00004     Vamp
cannam@0: 00005 
cannam@0: 00006     An API for audio analysis and feature extraction plugins.
cannam@0: 00007 
cannam@0: 00008     Centre for Digital Music, Queen Mary, University of London.
cannam@0: 00009     Copyright 2006 Chris Cannam.
cannam@0: 00010   
cannam@0: 00011     Permission is hereby granted, free of charge, to any person
cannam@0: 00012     obtaining a copy of this software and associated documentation
cannam@0: 00013     files (the "Software"), to deal in the Software without
cannam@0: 00014     restriction, including without limitation the rights to use, copy,
cannam@0: 00015     modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@0: 00016     of the Software, and to permit persons to whom the Software is
cannam@0: 00017     furnished to do so, subject to the following conditions:
cannam@0: 00018 
cannam@0: 00019     The above copyright notice and this permission notice shall be
cannam@0: 00020     included in all copies or substantial portions of the Software.
cannam@0: 00021 
cannam@0: 00022     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@0: 00023     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@0: 00024     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@0: 00025     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@0: 00026     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@0: 00027     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@0: 00028     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@0: 00029 
cannam@0: 00030     Except as contained in this notice, the names of the Centre for
cannam@0: 00031     Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@0: 00032     shall not be used in advertising or otherwise to promote the sale,
cannam@0: 00033     use or other dealings in this Software without prior written
cannam@0: 00034     authorization.
cannam@0: 00035 */
cannam@0: 00036 
cannam@0: 00037 #include "ZeroCrossing.h"
cannam@0: 00038 
cannam@0: 00039 using std::string;
cannam@0: 00040 using std::vector;
cannam@0: 00041 using std::cerr;
cannam@0: 00042 using std::endl;
cannam@0: 00043 
cannam@0: 00044 
cannam@0: 00045 ZeroCrossing::ZeroCrossing(float inputSampleRate) :
cannam@0: 00046     Plugin(inputSampleRate),
cannam@0: 00047     m_stepSize(0),
cannam@0: 00048     m_previousSample(0.0f)
cannam@0: 00049 {
cannam@0: 00050 }
cannam@0: 00051 
cannam@0: 00052 ZeroCrossing::~ZeroCrossing()
cannam@0: 00053 {
cannam@0: 00054 }
cannam@0: 00055 
cannam@0: 00056 string
cannam@0: 00057 ZeroCrossing::getIdentifier() const
cannam@0: 00058 {
cannam@0: 00059     return "zerocrossing";
cannam@0: 00060 }
cannam@0: 00061 
cannam@0: 00062 string
cannam@0: 00063 ZeroCrossing::getName() const
cannam@0: 00064 {
cannam@0: 00065     return "Zero Crossings";
cannam@0: 00066 }
cannam@0: 00067 
cannam@0: 00068 string
cannam@0: 00069 ZeroCrossing::getDescription() const
cannam@0: 00070 {
cannam@0: 00071     return "Detect and count zero crossing points";
cannam@0: 00072 }
cannam@0: 00073 
cannam@0: 00074 string
cannam@0: 00075 ZeroCrossing::getMaker() const
cannam@0: 00076 {
cannam@0: 00077     return "Vamp SDK Example Plugins";
cannam@0: 00078 }
cannam@0: 00079 
cannam@0: 00080 int
cannam@0: 00081 ZeroCrossing::getPluginVersion() const
cannam@0: 00082 {
cannam@0: 00083     return 2;
cannam@0: 00084 }
cannam@0: 00085 
cannam@0: 00086 string
cannam@0: 00087 ZeroCrossing::getCopyright() const
cannam@0: 00088 {
cannam@0: 00089     return "Freely redistributable (BSD license)";
cannam@0: 00090 }
cannam@0: 00091 
cannam@0: 00092 bool
cannam@0: 00093 ZeroCrossing::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@0: 00094 {
cannam@0: 00095     if (channels < getMinChannelCount() ||
cannam@0: 00096         channels > getMaxChannelCount()) return false;
cannam@0: 00097 
cannam@0: 00098     m_stepSize = std::min(stepSize, blockSize);
cannam@0: 00099 
cannam@0: 00100     return true;
cannam@0: 00101 }
cannam@0: 00102 
cannam@0: 00103 void
cannam@0: 00104 ZeroCrossing::reset()
cannam@0: 00105 {
cannam@0: 00106     m_previousSample = 0.0f;
cannam@0: 00107 }
cannam@0: 00108 
cannam@0: 00109 ZeroCrossing::OutputList
cannam@0: 00110 ZeroCrossing::getOutputDescriptors() const
cannam@0: 00111 {
cannam@0: 00112     OutputList list;
cannam@0: 00113 
cannam@0: 00114     OutputDescriptor zc;
cannam@0: 00115     zc.identifier = "counts";
cannam@0: 00116     zc.name = "Zero Crossing Counts";
cannam@0: 00117     zc.description = "The number of zero crossing points per processing block";
cannam@0: 00118     zc.unit = "crossings";
cannam@0: 00119     zc.hasFixedBinCount = true;
cannam@0: 00120     zc.binCount = 1;
cannam@0: 00121     zc.hasKnownExtents = false;
cannam@0: 00122     zc.isQuantized = true;
cannam@0: 00123     zc.quantizeStep = 1.0;
cannam@0: 00124     zc.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@0: 00125     list.push_back(zc);
cannam@0: 00126 
cannam@0: 00127     zc.identifier = "zerocrossings";
cannam@0: 00128     zc.name = "Zero Crossings";
cannam@0: 00129     zc.description = "The locations of zero crossing points";
cannam@0: 00130     zc.unit = "";
cannam@0: 00131     zc.hasFixedBinCount = true;
cannam@0: 00132     zc.binCount = 0;
cannam@0: 00133     zc.sampleType = OutputDescriptor::VariableSampleRate;
cannam@0: 00134     zc.sampleRate = m_inputSampleRate;
cannam@0: 00135     list.push_back(zc);
cannam@0: 00136 
cannam@0: 00137     return list;
cannam@0: 00138 }
cannam@0: 00139 
cannam@0: 00140 ZeroCrossing::FeatureSet
cannam@0: 00141 ZeroCrossing::process(const float *const *inputBuffers,
cannam@0: 00142                       Vamp::RealTime timestamp)
cannam@0: 00143 {
cannam@0: 00144     if (m_stepSize == 0) {
cannam@0: 00145         cerr << "ERROR: ZeroCrossing::process: "
cannam@0: 00146              << "ZeroCrossing has not been initialised"
cannam@0: 00147              << endl;
cannam@0: 00148         return FeatureSet();
cannam@0: 00149     }
cannam@0: 00150 
cannam@0: 00151     float prev = m_previousSample;
cannam@0: 00152     size_t count = 0;
cannam@0: 00153 
cannam@0: 00154     FeatureSet returnFeatures;
cannam@0: 00155 
cannam@0: 00156     for (size_t i = 0; i < m_stepSize; ++i) {
cannam@0: 00157 
cannam@0: 00158         float sample = inputBuffers[0][i];
cannam@0: 00159         bool crossing = false;
cannam@0: 00160 
cannam@0: 00161         if (sample <= 0.0) {
cannam@0: 00162             if (prev > 0.0) crossing = true;
cannam@0: 00163         } else if (sample > 0.0) {
cannam@0: 00164             if (prev <= 0.0) crossing = true;
cannam@0: 00165         }
cannam@0: 00166 
cannam@0: 00167         if (crossing) {
cannam@0: 00168             ++count; 
cannam@0: 00169             Feature feature;
cannam@0: 00170             feature.hasTimestamp = true;
cannam@0: 00171             feature.timestamp = timestamp +
cannam@0: 00172                 Vamp::RealTime::frame2RealTime(i, (size_t)m_inputSampleRate);
cannam@0: 00173             returnFeatures[1].push_back(feature);
cannam@0: 00174         }
cannam@0: 00175 
cannam@0: 00176         prev = sample;
cannam@0: 00177     }
cannam@0: 00178 
cannam@0: 00179     m_previousSample = prev;
cannam@0: 00180 
cannam@0: 00181     Feature feature;
cannam@0: 00182     feature.hasTimestamp = false;
cannam@0: 00183     feature.values.push_back(count);
cannam@0: 00184 
cannam@0: 00185     returnFeatures[0].push_back(feature);
cannam@0: 00186     return returnFeatures;
cannam@0: 00187 }
cannam@0: 00188 
cannam@0: 00189 ZeroCrossing::FeatureSet
cannam@0: 00190 ZeroCrossing::getRemainingFeatures()
cannam@0: 00191 {
cannam@0: 00192     return FeatureSet();
cannam@0: 00193 }
cannam@0: 00194 
cannam@0: 
cannam@0:
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