annotate examples/SpectralCentroid.cpp @ 255:88ef5ffdbe8d

* docs
author cannam
date Wed, 12 Nov 2008 14:11:01 +0000
parents 3cf5bd155e5b
children 91574fc544db
rev   line source
cannam@0 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
cannam@0 2
cannam@0 3 /*
cannam@0 4 Vamp
cannam@0 5
cannam@0 6 An API for audio analysis and feature extraction plugins.
cannam@0 7
cannam@0 8 Centre for Digital Music, Queen Mary, University of London.
cannam@0 9 Copyright 2006 Chris Cannam.
cannam@0 10
cannam@0 11 Permission is hereby granted, free of charge, to any person
cannam@0 12 obtaining a copy of this software and associated documentation
cannam@0 13 files (the "Software"), to deal in the Software without
cannam@0 14 restriction, including without limitation the rights to use, copy,
cannam@0 15 modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@0 16 of the Software, and to permit persons to whom the Software is
cannam@0 17 furnished to do so, subject to the following conditions:
cannam@0 18
cannam@0 19 The above copyright notice and this permission notice shall be
cannam@0 20 included in all copies or substantial portions of the Software.
cannam@0 21
cannam@0 22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@0 23 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@0 24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@6 25 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@0 26 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@0 27 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@0 28 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@0 29
cannam@0 30 Except as contained in this notice, the names of the Centre for
cannam@0 31 Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@0 32 shall not be used in advertising or otherwise to promote the sale,
cannam@0 33 use or other dealings in this Software without prior written
cannam@0 34 authorization.
cannam@0 35 */
cannam@0 36
cannam@0 37 #include "SpectralCentroid.h"
cannam@0 38
cannam@0 39 using std::string;
cannam@0 40 using std::vector;
cannam@0 41 using std::cerr;
cannam@0 42 using std::endl;
cannam@0 43
cannam@210 44 #include <math.h>
cannam@7 45
cannam@210 46 #ifdef WIN32
cannam@210 47 #define isnan(x) false
cannam@210 48 #define isinf(x) false
cannam@210 49 #endif
cannam@0 50
cannam@0 51 SpectralCentroid::SpectralCentroid(float inputSampleRate) :
cannam@0 52 Plugin(inputSampleRate),
cannam@0 53 m_stepSize(0),
cannam@21 54 m_blockSize(0)
cannam@0 55 {
cannam@0 56 }
cannam@0 57
cannam@0 58 SpectralCentroid::~SpectralCentroid()
cannam@0 59 {
cannam@0 60 }
cannam@0 61
cannam@0 62 string
cannam@49 63 SpectralCentroid::getIdentifier() const
cannam@0 64 {
cannam@0 65 return "spectralcentroid";
cannam@0 66 }
cannam@0 67
cannam@0 68 string
cannam@49 69 SpectralCentroid::getName() const
cannam@49 70 {
cannam@49 71 return "Spectral Centroid";
cannam@49 72 }
cannam@49 73
cannam@49 74 string
cannam@0 75 SpectralCentroid::getDescription() const
cannam@0 76 {
cannam@49 77 return "Calculate the centroid frequency of the spectrum of the input signal";
cannam@0 78 }
cannam@0 79
cannam@0 80 string
cannam@0 81 SpectralCentroid::getMaker() const
cannam@0 82 {
cannam@43 83 return "Vamp SDK Example Plugins";
cannam@0 84 }
cannam@0 85
cannam@0 86 int
cannam@0 87 SpectralCentroid::getPluginVersion() const
cannam@0 88 {
cannam@0 89 return 2;
cannam@0 90 }
cannam@0 91
cannam@0 92 string
cannam@0 93 SpectralCentroid::getCopyright() const
cannam@0 94 {
cannam@7 95 return "Freely redistributable (BSD license)";
cannam@0 96 }
cannam@0 97
cannam@0 98 bool
cannam@0 99 SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@0 100 {
cannam@0 101 if (channels < getMinChannelCount() ||
cannam@0 102 channels > getMaxChannelCount()) return false;
cannam@0 103
cannam@0 104 m_stepSize = stepSize;
cannam@0 105 m_blockSize = blockSize;
cannam@0 106
cannam@0 107 return true;
cannam@0 108 }
cannam@0 109
cannam@0 110 void
cannam@0 111 SpectralCentroid::reset()
cannam@0 112 {
cannam@0 113 }
cannam@0 114
cannam@0 115 SpectralCentroid::OutputList
cannam@0 116 SpectralCentroid::getOutputDescriptors() const
cannam@0 117 {
cannam@0 118 OutputList list;
cannam@0 119
cannam@0 120 OutputDescriptor d;
cannam@49 121 d.identifier = "logcentroid";
cannam@49 122 d.name = "Log Frequency Centroid";
cannam@49 123 d.description = "Centroid of the log weighted frequency spectrum";
cannam@0 124 d.unit = "Hz";
cannam@9 125 d.hasFixedBinCount = true;
cannam@9 126 d.binCount = 1;
cannam@0 127 d.hasKnownExtents = false;
cannam@0 128 d.isQuantized = false;
cannam@0 129 d.sampleType = OutputDescriptor::OneSamplePerStep;
cannam@0 130 list.push_back(d);
cannam@0 131
cannam@49 132 d.identifier = "linearcentroid";
cannam@49 133 d.name = "Linear Frequency Centroid";
cannam@49 134 d.description = "Centroid of the linear frequency spectrum";
cannam@0 135 list.push_back(d);
cannam@0 136
cannam@0 137 return list;
cannam@0 138 }
cannam@0 139
cannam@0 140 SpectralCentroid::FeatureSet
cannam@190 141 SpectralCentroid::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
cannam@0 142 {
cannam@0 143 if (m_stepSize == 0) {
cannam@0 144 cerr << "ERROR: SpectralCentroid::process: "
cannam@0 145 << "SpectralCentroid has not been initialised"
cannam@0 146 << endl;
cannam@0 147 return FeatureSet();
cannam@0 148 }
cannam@0 149
cannam@0 150 double numLin = 0.0, numLog = 0.0, denom = 0.0;
cannam@0 151
cannam@47 152 for (size_t i = 1; i <= m_blockSize/2; ++i) {
cannam@0 153 double freq = (double(i) * m_inputSampleRate) / m_blockSize;
cannam@0 154 double real = inputBuffers[0][i*2];
cannam@0 155 double imag = inputBuffers[0][i*2 + 1];
cannam@243 156 double scalemag = sqrt(real * real + imag * imag) / (m_blockSize/2);
cannam@243 157 numLin += freq * scalemag;
cannam@243 158 numLog += log10f(freq) * scalemag;
cannam@243 159 denom += scalemag;
cannam@0 160 }
cannam@0 161
cannam@0 162 FeatureSet returnFeatures;
cannam@0 163
cannam@0 164 if (denom != 0.0) {
cannam@0 165 float centroidLin = float(numLin / denom);
cannam@19 166 float centroidLog = powf(10, float(numLog / denom));
cannam@47 167
cannam@0 168 Feature feature;
cannam@0 169 feature.hasTimestamp = false;
cannam@243 170
cannam@243 171 if (!isnan(centroidLog) && !isinf(centroidLog)) {
cannam@243 172 feature.values.push_back(centroidLog);
cannam@243 173 }
cannam@0 174 returnFeatures[0].push_back(feature);
cannam@47 175
cannam@243 176 feature.values.clear();
cannam@243 177 if (!isnan(centroidLin) && !isinf(centroidLin)) {
cannam@243 178 feature.values.push_back(centroidLin);
cannam@243 179 }
cannam@0 180 returnFeatures[1].push_back(feature);
cannam@0 181 }
cannam@0 182
cannam@0 183 return returnFeatures;
cannam@0 184 }
cannam@0 185
cannam@0 186 SpectralCentroid::FeatureSet
cannam@0 187 SpectralCentroid::getRemainingFeatures()
cannam@0 188 {
cannam@0 189 return FeatureSet();
cannam@0 190 }
cannam@0 191