3c430ef1ed66/code-docs/PowerSpectrum_8cpp_source.html

00001 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1: 00002
Chris@1: 00003 /*
Chris@1: 00004     Vamp
Chris@1: 00005
Chris@1: 00006     An API for audio analysis and feature extraction plugins.
Chris@1: 00007
Chris@1: 00008     Centre for Digital Music, Queen Mary, University of London.
Chris@1: 00009     Copyright 2008 QMUL.
Chris@1: 00010
Chris@1: 00011     Permission is hereby granted, free of charge, to any person
Chris@1: 00012     obtaining a copy of this software and associated documentation
Chris@1: 00013     files (the "Software"), to deal in the Software without
Chris@1: 00014     restriction, including without limitation the rights to use, copy,
Chris@1: 00015     modify, merge, publish, distribute, sublicense, and/or sell copies
Chris@1: 00016     of the Software, and to permit persons to whom the Software is
Chris@1: 00017     furnished to do so, subject to the following conditions:
Chris@1: 00018
Chris@1: 00019     The above copyright notice and this permission notice shall be
Chris@1: 00020     included in all copies or substantial portions of the Software.
Chris@1: 00021
Chris@1: 00022     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
Chris@1: 00023     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
Chris@1: 00024     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
Chris@1: 00025     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
Chris@1: 00026     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
Chris@1: 00027     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
Chris@1: 00028     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Chris@1: 00029
Chris@1: 00030     Except as contained in this notice, the names of the Centre for
Chris@1: 00031     Digital Music; Queen Mary, University of London; and Chris Cannam
Chris@1: 00032     shall not be used in advertising or otherwise to promote the sale,
Chris@1: 00033     use or other dealings in this Software without prior written
Chris@1: 00034     authorization.
Chris@1: 00035 */
Chris@1: 00036
Chris@1: 00037 #include "PowerSpectrum.h"
Chris@1: 00038
Chris@1: 00039 using std::string;
Chris@1: 00040 using std::cerr;
Chris@1: 00041 using std::endl;
Chris@1: 00042
Chris@1: 00043 #include <math.h>
Chris@1: 00044
Chris@1: 00045 PowerSpectrum::PowerSpectrum(float inputSampleRate) :
Chris@1: 00046     Plugin(inputSampleRate),
Chris@1: 00047     m_blockSize(0)
Chris@1: 00048 {
Chris@1: 00049 }
Chris@1: 00050
Chris@1: 00051 PowerSpectrum::~PowerSpectrum()
Chris@1: 00052 {
Chris@1: 00053 }
Chris@1: 00054
Chris@1: 00055 string
Chris@1: 00056 PowerSpectrum::getIdentifier() const
Chris@1: 00057 {
Chris@1: 00058     return "powerspectrum";
Chris@1: 00059 }
Chris@1: 00060
Chris@1: 00061 string
Chris@1: 00062 PowerSpectrum::getName() const
Chris@1: 00063 {
Chris@1: 00064     return "Simple Power Spectrum";
Chris@1: 00065 }
Chris@1: 00066
Chris@1: 00067 string
Chris@1: 00068 PowerSpectrum::getDescription() const
Chris@1: 00069 {
Chris@1: 00070     return "Return the power spectrum of a signal";
Chris@1: 00071 }
Chris@1: 00072
Chris@1: 00073 string
Chris@1: 00074 PowerSpectrum::getMaker() const
Chris@1: 00075 {
Chris@1: 00076     return "Vamp SDK Example Plugins";
Chris@1: 00077 }
Chris@1: 00078
Chris@1: 00079 int
Chris@1: 00080 PowerSpectrum::getPluginVersion() const
Chris@1: 00081 {
Chris@1: 00082     return 1;
Chris@1: 00083 }
Chris@1: 00084
Chris@1: 00085 string
Chris@1: 00086 PowerSpectrum::getCopyright() const
Chris@1: 00087 {
Chris@1: 00088     return "Freely redistributable (BSD license)";
Chris@1: 00089 }
Chris@1: 00090
Chris@1: 00091 bool
Chris@1: 00092 PowerSpectrum::initialise(size_t channels, size_t stepSize, size_t blockSize)
Chris@1: 00093 {
Chris@1: 00094     if (channels < getMinChannelCount() ||
Chris@1: 00095         channels > getMaxChannelCount()) return false;
Chris@1: 00096
Chris@1: 00097     m_blockSize = blockSize;
Chris@1: 00098
Chris@1: 00099     return true;
Chris@1: 00100 }
Chris@1: 00101
Chris@1: 00102 void
Chris@1: 00103 PowerSpectrum::reset()
Chris@1: 00104 {
Chris@1: 00105 }
Chris@1: 00106
Chris@1: 00107 PowerSpectrum::OutputList
Chris@1: 00108 PowerSpectrum::getOutputDescriptors() const
Chris@1: 00109 {
Chris@1: 00110     OutputList list;
Chris@1: 00111
Chris@1: 00112     OutputDescriptor d;
Chris@1: 00113     d.identifier = "powerspectrum";
Chris@1: 00114     d.name = "Power Spectrum";
Chris@1: 00115     d.description = "Power values of the frequency spectrum bins calculated from the input signal";
Chris@1: 00116     d.unit = "";
Chris@1: 00117     d.hasFixedBinCount = true;
Chris@1: 00118     if (m_blockSize == 0) {
Chris@1: 00119         // Just so as not to return "1".  This is the bin count that
Chris@1: 00120         // would result from a block size of 1024, which is a likely
Chris@1: 00121         // default -- but the host should always set the block size
Chris@1: 00122         // before querying the bin count for certain.
Chris@1: 00123         d.binCount = 513;
Chris@1: 00124     } else {
Chris@1: 00125         d.binCount = m_blockSize / 2 + 1;
Chris@1: 00126     }
Chris@1: 00127     d.hasKnownExtents = false;
Chris@1: 00128     d.isQuantized = false;
Chris@1: 00129     d.sampleType = OutputDescriptor::OneSamplePerStep;
Chris@1: 00130     list.push_back(d);
Chris@1: 00131
Chris@1: 00132     return list;
Chris@1: 00133 }
Chris@1: 00134
Chris@1: 00135 PowerSpectrum::FeatureSet
Chris@1: 00136 PowerSpectrum::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
Chris@1: 00137 {
Chris@1: 00138     FeatureSet fs;
Chris@1: 00139
Chris@1: 00140     if (m_blockSize == 0) {
Chris@1: 00141         cerr << "ERROR: PowerSpectrum::process: Not initialised" << endl;
Chris@1: 00142         return fs;
Chris@1: 00143     }
Chris@1: 00144
Chris@1: 00145     size_t n = m_blockSize / 2 + 1;
Chris@1: 00146     const float *fbuf = inputBuffers[0];
Chris@1: 00147
Chris@1: 00148     Feature feature;
Chris@1: 00149     feature.hasTimestamp = false;
Chris@1: 00150     feature.values.reserve(n); // optional
Chris@1: 00151
Chris@1: 00152     for (size_t i = 0; i < n; ++i) {
Chris@1: 00153
Chris@1: 00154         double real = fbuf[i * 2];
Chris@1: 00155         double imag = fbuf[i * 2 + 1];
Chris@1: 00156
Chris@1: 00157         feature.values.push_back(real * real + imag * imag);
Chris@1: 00158     }
Chris@1: 00159
Chris@1: 00160     fs[0].push_back(feature);
Chris@1: 00161
Chris@1: 00162     return fs;
Chris@1: 00163 }
Chris@1: 00164
Chris@1: 00165 PowerSpectrum::FeatureSet
Chris@1: 00166 PowerSpectrum::getRemainingFeatures()
Chris@1: 00167 {
Chris@1: 00168     return FeatureSet();
Chris@1: 00169 }
Chris@1: 00170
Chris@1: