cannam@0:
SpectralCentroid.cpp

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 "SpectralCentroid.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@21: 00044 #include <math.h>
cannam@0: 00045 
cannam@21: 00046 #ifdef WIN32
cannam@21: 00047 #define isnan(x) false
cannam@21: 00048 #define isinf(x) false
cannam@21: 00049 #endif
cannam@21: 00050 
cannam@21: 00051 SpectralCentroid::SpectralCentroid(float inputSampleRate) :
cannam@21: 00052     Plugin(inputSampleRate),
cannam@21: 00053     m_stepSize(0),
cannam@21: 00054     m_blockSize(0)
cannam@0: 00055 {
cannam@0: 00056 }
cannam@0: 00057 
cannam@21: 00058 SpectralCentroid::~SpectralCentroid()
cannam@21: 00059 {
cannam@21: 00060 }
cannam@21: 00061 
cannam@21: 00062 string
cannam@21: 00063 SpectralCentroid::getIdentifier() const
cannam@21: 00064 {
cannam@21: 00065     return "spectralcentroid";
cannam@21: 00066 }
cannam@21: 00067 
cannam@21: 00068 string
cannam@21: 00069 SpectralCentroid::getName() const
cannam@21: 00070 {
cannam@21: 00071     return "Spectral Centroid";
cannam@21: 00072 }
cannam@21: 00073 
cannam@21: 00074 string
cannam@21: 00075 SpectralCentroid::getDescription() const
cannam@21: 00076 {
cannam@21: 00077     return "Calculate the centroid frequency of the spectrum of the input signal";
cannam@21: 00078 }
cannam@21: 00079 
cannam@21: 00080 string
cannam@21: 00081 SpectralCentroid::getMaker() const
cannam@21: 00082 {
cannam@21: 00083     return "Vamp SDK Example Plugins";
cannam@21: 00084 }
cannam@21: 00085 
cannam@21: 00086 int
cannam@21: 00087 SpectralCentroid::getPluginVersion() const
cannam@21: 00088 {
cannam@21: 00089     return 2;
cannam@21: 00090 }
cannam@21: 00091 
cannam@21: 00092 string
cannam@21: 00093 SpectralCentroid::getCopyright() const
cannam@21: 00094 {
cannam@21: 00095     return "Freely redistributable (BSD license)";
cannam@21: 00096 }
cannam@21: 00097 
cannam@21: 00098 bool
cannam@21: 00099 SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@21: 00100 {
cannam@21: 00101     if (channels < getMinChannelCount() ||
cannam@21: 00102         channels > getMaxChannelCount()) return false;
cannam@21: 00103 
cannam@21: 00104     m_stepSize = stepSize;
cannam@21: 00105     m_blockSize = blockSize;
cannam@21: 00106 
cannam@21: 00107     return true;
cannam@21: 00108 }
cannam@21: 00109 
cannam@21: 00110 void
cannam@21: 00111 SpectralCentroid::reset()
cannam@21: 00112 {
cannam@21: 00113 }
cannam@21: 00114 
cannam@21: 00115 SpectralCentroid::OutputList
cannam@21: 00116 SpectralCentroid::getOutputDescriptors() const
cannam@21: 00117 {
cannam@21: 00118     OutputList list;
cannam@21: 00119 
cannam@21: 00120     OutputDescriptor d;
cannam@21: 00121     d.identifier = "logcentroid";
cannam@21: 00122     d.name = "Log Frequency Centroid";
cannam@21: 00123     d.description = "Centroid of the log weighted frequency spectrum";
cannam@21: 00124     d.unit = "Hz";
cannam@21: 00125     d.hasFixedBinCount = true;
cannam@21: 00126     d.binCount = 1;
cannam@21: 00127     d.hasKnownExtents = false;
cannam@21: 00128     d.isQuantized = false;
cannam@21: 00129     d.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@21: 00130     list.push_back(d);
cannam@21: 00131 
cannam@21: 00132     d.identifier = "linearcentroid";
cannam@21: 00133     d.name = "Linear Frequency Centroid";
cannam@21: 00134     d.description = "Centroid of the linear frequency spectrum";
cannam@21: 00135     list.push_back(d);
cannam@21: 00136 
cannam@21: 00137     return list;
cannam@21: 00138 }
cannam@21: 00139 
cannam@21: 00140 SpectralCentroid::FeatureSet
cannam@21: 00141 SpectralCentroid::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
cannam@21: 00142 {
cannam@21: 00143     if (m_stepSize == 0) {
cannam@21: 00144         cerr << "ERROR: SpectralCentroid::process: "
cannam@21: 00145              << "SpectralCentroid has not been initialised"
cannam@21: 00146              << endl;
cannam@21: 00147         return FeatureSet();
cannam@21: 00148     }
cannam@21: 00149 
cannam@21: 00150     double numLin = 0.0, numLog = 0.0, denom = 0.0;
cannam@21: 00151 
cannam@21: 00152     for (size_t i = 1; i <= m_blockSize/2; ++i) {
cannam@21: 00153         double freq = (double(i) * m_inputSampleRate) / m_blockSize;
cannam@21: 00154         double real = inputBuffers[0][i*2];
cannam@21: 00155         double imag = inputBuffers[0][i*2 + 1];
cannam@21: 00156         double scalemag = sqrt(real * real + imag * imag) / (m_blockSize/2);
cannam@21: 00157         numLin += freq * scalemag;
cannam@21: 00158         numLog += log10f(freq) * scalemag;
cannam@21: 00159         denom += scalemag;
cannam@21: 00160     }
cannam@0: 00161 
cannam@21: 00162     FeatureSet returnFeatures;
cannam@21: 00163 
cannam@21: 00164     if (denom != 0.0) {
cannam@21: 00165         float centroidLin = float(numLin / denom);
cannam@21: 00166         float centroidLog = powf(10, float(numLog / denom));
cannam@21: 00167 
cannam@21: 00168         Feature feature;
cannam@21: 00169         feature.hasTimestamp = false;
cannam@21: 00170 
cannam@21: 00171         if (!isnan(centroidLog) && !isinf(centroidLog)) {
cannam@21: 00172             feature.values.push_back(centroidLog);
cannam@21: 00173         }
cannam@21: 00174         returnFeatures[0].push_back(feature);
cannam@21: 00175 
cannam@21: 00176         feature.values.clear();
cannam@21: 00177         if (!isnan(centroidLin) && !isinf(centroidLin)) {
cannam@21: 00178             feature.values.push_back(centroidLin);
cannam@21: 00179         }
cannam@21: 00180         returnFeatures[1].push_back(feature);
cannam@21: 00181     }
cannam@0: 00182 
cannam@21: 00183     return returnFeatures;
cannam@21: 00184 }
cannam@21: 00185 
cannam@21: 00186 SpectralCentroid::FeatureSet
cannam@21: 00187 SpectralCentroid::getRemainingFeatures()
cannam@21: 00188 {
cannam@21: 00189     return FeatureSet();
cannam@21: 00190 }
cannam@21: 00191 
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