cannam@21:
PowerSpectrum.cpp

00001 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
cannam@21: 00002 
cannam@21: 00003 /*
cannam@21: 00004     Vamp
cannam@21: 00005 
cannam@21: 00006     An API for audio analysis and feature extraction plugins.
cannam@21: 00007 
cannam@21: 00008     Centre for Digital Music, Queen Mary, University of London.
cannam@21: 00009     Copyright 2008 QMUL.
cannam@21: 00010   
cannam@21: 00011     Permission is hereby granted, free of charge, to any person
cannam@21: 00012     obtaining a copy of this software and associated documentation
cannam@21: 00013     files (the "Software"), to deal in the Software without
cannam@21: 00014     restriction, including without limitation the rights to use, copy,
cannam@21: 00015     modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@21: 00016     of the Software, and to permit persons to whom the Software is
cannam@21: 00017     furnished to do so, subject to the following conditions:
cannam@21: 00018 
cannam@21: 00019     The above copyright notice and this permission notice shall be
cannam@21: 00020     included in all copies or substantial portions of the Software.
cannam@21: 00021 
cannam@21: 00022     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@21: 00023     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@21: 00024     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@21: 00025     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@21: 00026     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@21: 00027     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@21: 00028     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@21: 00029 
cannam@21: 00030     Except as contained in this notice, the names of the Centre for
cannam@21: 00031     Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@21: 00032     shall not be used in advertising or otherwise to promote the sale,
cannam@21: 00033     use or other dealings in this Software without prior written
cannam@21: 00034     authorization.
cannam@21: 00035 */
cannam@21: 00036 
cannam@21: 00037 #include "PowerSpectrum.h"
cannam@21: 00038 
cannam@21: 00039 using std::string;
cannam@21: 00040 using std::cerr;
cannam@21: 00041 using std::endl;
cannam@21: 00042 
cannam@21: 00043 #include <math.h>
cannam@21: 00044 
cannam@21: 00045 PowerSpectrum::PowerSpectrum(float inputSampleRate) :
cannam@21: 00046     Plugin(inputSampleRate),
cannam@21: 00047     m_blockSize(0)
cannam@21: 00048 {
cannam@21: 00049 }
cannam@21: 00050 
cannam@21: 00051 PowerSpectrum::~PowerSpectrum()
cannam@21: 00052 {
cannam@21: 00053 }
cannam@21: 00054 
cannam@21: 00055 string
cannam@21: 00056 PowerSpectrum::getIdentifier() const
cannam@21: 00057 {
cannam@21: 00058     return "powerspectrum";
cannam@21: 00059 }
cannam@21: 00060 
cannam@21: 00061 string
cannam@21: 00062 PowerSpectrum::getName() const
cannam@21: 00063 {
cannam@21: 00064     return "Simple Power Spectrum";
cannam@21: 00065 }
cannam@21: 00066 
cannam@21: 00067 string
cannam@21: 00068 PowerSpectrum::getDescription() const
cannam@21: 00069 {
cannam@21: 00070     return "Return the power spectrum of a signal";
cannam@21: 00071 }
cannam@21: 00072 
cannam@21: 00073 string
cannam@21: 00074 PowerSpectrum::getMaker() const
cannam@21: 00075 {
cannam@21: 00076     return "Vamp SDK Example Plugins";
cannam@21: 00077 }
cannam@21: 00078 
cannam@21: 00079 int
cannam@21: 00080 PowerSpectrum::getPluginVersion() const
cannam@21: 00081 {
cannam@21: 00082     return 1;
cannam@21: 00083 }
cannam@21: 00084 
cannam@21: 00085 string
cannam@21: 00086 PowerSpectrum::getCopyright() const
cannam@21: 00087 {
cannam@21: 00088     return "Freely redistributable (BSD license)";
cannam@21: 00089 }
cannam@21: 00090 
cannam@21: 00091 bool
cannam@21: 00092 PowerSpectrum::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@21: 00093 {
cannam@21: 00094     if (channels < getMinChannelCount() ||
cannam@21: 00095         channels > getMaxChannelCount()) return false;
cannam@21: 00096 
cannam@21: 00097     m_blockSize = blockSize;
cannam@21: 00098 
cannam@21: 00099     return true;
cannam@21: 00100 }
cannam@21: 00101 
cannam@21: 00102 void
cannam@21: 00103 PowerSpectrum::reset()
cannam@21: 00104 {
cannam@21: 00105 }
cannam@21: 00106 
cannam@21: 00107 PowerSpectrum::OutputList
cannam@21: 00108 PowerSpectrum::getOutputDescriptors() const
cannam@21: 00109 {
cannam@21: 00110     OutputList list;
cannam@21: 00111 
cannam@21: 00112     OutputDescriptor d;
cannam@21: 00113     d.identifier = "powerspectrum";
cannam@21: 00114     d.name = "Power Spectrum";
cannam@21: 00115     d.description = "Power values of the frequency spectrum bins calculated from the input signal";
cannam@21: 00116     d.unit = "";
cannam@21: 00117     d.hasFixedBinCount = true;
cannam@21: 00118     if (m_blockSize == 0) {
cannam@21: 00119         // Just so as not to return "1".  This is the bin count that
cannam@21: 00120         // would result from a block size of 1024, which is a likely
cannam@21: 00121         // default -- but the host should always set the block size
cannam@21: 00122         // before querying the bin count for certain.
cannam@21: 00123         d.binCount = 513;
cannam@21: 00124     } else {
cannam@21: 00125         d.binCount = m_blockSize / 2 + 1;
cannam@21: 00126     }
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     return list;
cannam@21: 00133 }
cannam@21: 00134 
cannam@21: 00135 PowerSpectrum::FeatureSet
cannam@21: 00136 PowerSpectrum::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
cannam@21: 00137 {
cannam@21: 00138     FeatureSet fs;
cannam@21: 00139 
cannam@21: 00140     if (m_blockSize == 0) {
cannam@21: 00141         cerr << "ERROR: PowerSpectrum::process: Not initialised" << endl;
cannam@21: 00142         return fs;
cannam@21: 00143     }
cannam@21: 00144 
cannam@21: 00145     size_t n = m_blockSize / 2 + 1;
cannam@21: 00146     const float *fbuf = inputBuffers[0];
cannam@21: 00147 
cannam@21: 00148     Feature feature;
cannam@21: 00149     feature.hasTimestamp = false;
cannam@21: 00150     feature.values.reserve(n); // optional
cannam@21: 00151 
cannam@21: 00152     for (size_t i = 0; i < n; ++i) {
cannam@21: 00153 
cannam@21: 00154         double real = fbuf[i * 2];
cannam@21: 00155         double imag = fbuf[i * 2 + 1];
cannam@21: 00156 
cannam@21: 00157         feature.values.push_back(real * real + imag * imag);
cannam@21: 00158     }
cannam@21: 00159 
cannam@21: 00160     fs[0].push_back(feature);
cannam@21: 00161 
cannam@21: 00162     return fs;
cannam@21: 00163 }
cannam@21: 00164 
cannam@21: 00165 PowerSpectrum::FeatureSet
cannam@21: 00166 PowerSpectrum::getRemainingFeatures()
cannam@21: 00167 {
cannam@21: 00168     return FeatureSet();
cannam@21: 00169 }
cannam@21: 00170 
cannam@21: