SpectralCentroid.cpp
Go to the documentation of this file.
/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
/*
Vamp
An API for audio analysis and feature extraction plugins.
Centre for Digital Music, Queen Mary, University of London.
Copyright 2006 Chris Cannam.
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the names of the Centre for
Digital Music; Queen Mary, University of London; and Chris Cannam
shall not be used in advertising or otherwise to promote the sale,
use or other dealings in this Software without prior written
authorization.
*/
#include "SpectralCentroid.h"
using std::string;
using std::vector;
using std::cerr;
using std::endl;
#include <math.h>
#ifdef __SUNPRO_CC
#include <ieeefp.h>
#define isinf(x) (!finite(x))
#endif
#ifdef WIN32
#define isnan(x) false
#define isinf(x) false
#endif
SpectralCentroid::SpectralCentroid(float inputSampleRate) :
Plugin(inputSampleRate),
m_stepSize(0),
m_blockSize(0)
{
}
SpectralCentroid::~SpectralCentroid()
{
}
string
SpectralCentroid::getIdentifier() const
{
return "spectralcentroid";
}
string
SpectralCentroid::getName() const
{
return "Spectral Centroid";
}
string
SpectralCentroid::getDescription() const
{
return "Calculate the centroid frequency of the spectrum of the input signal";
}
string
SpectralCentroid::getMaker() const
{
return "Vamp SDK Example Plugins";
}
int
SpectralCentroid::getPluginVersion() const
{
return 2;
}
string
SpectralCentroid::getCopyright() const
{
return "Freely redistributable (BSD license)";
}
bool
SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
{
if (channels < getMinChannelCount() ||
channels > getMaxChannelCount()) return false;
m_stepSize = stepSize;
m_blockSize = blockSize;
return true;
}
void
SpectralCentroid::reset()
{
}
SpectralCentroid::OutputList
SpectralCentroid::getOutputDescriptors() const
{
OutputList list;
OutputDescriptor d;
d.identifier = "logcentroid";
d.name = "Log Frequency Centroid";
d.description = "Centroid of the log weighted frequency spectrum";
d.unit = "Hz";
d.hasFixedBinCount = true;
d.binCount = 1;
d.hasKnownExtents = false;
d.isQuantized = false;
d.sampleType = OutputDescriptor::OneSamplePerStep;
list.push_back(d);
d.identifier = "linearcentroid";
d.name = "Linear Frequency Centroid";
d.description = "Centroid of the linear frequency spectrum";
list.push_back(d);
return list;
}
SpectralCentroid::FeatureSet
SpectralCentroid::process(const float *const *inputBuffers, Vamp::RealTime)
{
if (m_stepSize == 0) {
cerr << "ERROR: SpectralCentroid::process: "
<< "SpectralCentroid has not been initialised"
<< endl;
return FeatureSet();
}
double numLin = 0.0, numLog = 0.0, denom = 0.0;
for (size_t i = 1; i <= m_blockSize/2; ++i) {
double freq = (double(i) * m_inputSampleRate) / m_blockSize;
double real = inputBuffers[0][i*2];
double imag = inputBuffers[0][i*2 + 1];
double scalemag = sqrt(real * real + imag * imag) / (m_blockSize/2);
numLin += freq * scalemag;
numLog += log10f(freq) * scalemag;
denom += scalemag;
}
FeatureSet returnFeatures;
if (denom != 0.0) {
float centroidLin = float(numLin / denom);
float centroidLog = powf(10, float(numLog / denom));
Feature feature;
feature.hasTimestamp = false;
if (!isnan(centroidLog) && !isinf(centroidLog)) {
feature.values.push_back(centroidLog);
}
returnFeatures[0].push_back(feature);
feature.values.clear();
if (!isnan(centroidLin) && !isinf(centroidLin)) {
feature.values.push_back(centroidLin);
}
returnFeatures[1].push_back(feature);
}
return returnFeatures;
}
SpectralCentroid::FeatureSet
SpectralCentroid::getRemainingFeatures()
{
return FeatureSet();
}
SpectralCentroid.h
SpectralCentroid::getPluginVersion
int getPluginVersion() const
Get the version number of the plugin.
Definition SpectralCentroid.cpp:92
SpectralCentroid::m_blockSize
size_t m_blockSize
Definition SpectralCentroid.h:74
SpectralCentroid::SpectralCentroid
SpectralCentroid(float inputSampleRate)
Definition SpectralCentroid.cpp:56
SpectralCentroid::~SpectralCentroid
virtual ~SpectralCentroid()
Definition SpectralCentroid.cpp:63
SpectralCentroid::m_stepSize
size_t m_stepSize
Definition SpectralCentroid.h:73
SpectralCentroid::getIdentifier
std::string getIdentifier() const
Get the computer-usable name of the plugin.
Definition SpectralCentroid.cpp:68
SpectralCentroid::getRemainingFeatures
FeatureSet getRemainingFeatures()
After all blocks have been processed, calculate and return any remaining features derived from the co...
Definition SpectralCentroid.cpp:192
SpectralCentroid::reset
void reset()
Reset the plugin after use, to prepare it for another clean run.
Definition SpectralCentroid.cpp:116
SpectralCentroid::getMaker
std::string getMaker() const
Get the name of the author or vendor of the plugin in human-readable form.
Definition SpectralCentroid.cpp:86
SpectralCentroid::getName
std::string getName() const
Get a human-readable name or title of the plugin.
Definition SpectralCentroid.cpp:74
SpectralCentroid::initialise
bool initialise(size_t channels, size_t stepSize, size_t blockSize)
Initialise a plugin to prepare it for use with the given number of input channels,...
Definition SpectralCentroid.cpp:104
SpectralCentroid::getDescription
std::string getDescription() const
Get a human-readable description for the plugin, typically a line of text that may optionally be disp...
Definition SpectralCentroid.cpp:80
SpectralCentroid::process
FeatureSet process(const float *const *inputBuffers, Vamp::RealTime timestamp)
Process a single block of input data.
Definition SpectralCentroid.cpp:146
SpectralCentroid::getOutputDescriptors
OutputList getOutputDescriptors() const
Get the outputs of this plugin.
Definition SpectralCentroid.cpp:121
SpectralCentroid::getCopyright
std::string getCopyright() const
Get the copyright statement or licensing summary for the plugin.
Definition SpectralCentroid.cpp:98
Vamp::Plugin::getMaxChannelCount
virtual size_t getMaxChannelCount() const
Get the maximum supported number of input channels.
Definition vamp-sdk/Plugin.h:204
Vamp::Plugin::OutputList
std::vector< OutputDescriptor > OutputList
Definition vamp-sdk/Plugin.h:335
Vamp::Plugin::FeatureSet
std::map< int, FeatureList > FeatureSet
Definition vamp-sdk/Plugin.h:395
Vamp::Plugin::m_inputSampleRate
float m_inputSampleRate
Definition vamp-sdk/Plugin.h:449
Vamp::Plugin::getMinChannelCount
virtual size_t getMinChannelCount() const
Get the minimum supported number of input channels.
Definition vamp-sdk/Plugin.h:199
Vamp::Plugin::Feature
Definition vamp-sdk/Plugin.h:345
Vamp::Plugin::Feature::values
std::vector< float > values
Results for a single sample of this feature.
Definition vamp-sdk/Plugin.h:382
Vamp::Plugin::Feature::hasTimestamp
bool hasTimestamp
True if an output feature has its own timestamp.
Definition vamp-sdk/Plugin.h:352
Vamp::Plugin::OutputDescriptor
Definition vamp-sdk/Plugin.h:207
Vamp::Plugin::OutputDescriptor::sampleType
SampleType sampleType
Positioning in time of the output results.
Definition vamp-sdk/Plugin.h:302
Vamp::Plugin::OutputDescriptor::isQuantized
bool isQuantized
True if the output values are quantized to a particular resolution.
Definition vamp-sdk/Plugin.h:278
Vamp::Plugin::OutputDescriptor::unit
std::string unit
The unit of the output, in human-readable form.
Definition vamp-sdk/Plugin.h:232
Vamp::Plugin::OutputDescriptor::name
std::string name
The human-readable name of the output.
Definition vamp-sdk/Plugin.h:220
Vamp::Plugin::OutputDescriptor::identifier
std::string identifier
The name of the output, in computer-usable form.
Definition vamp-sdk/Plugin.h:214
Vamp::Plugin::OutputDescriptor::hasKnownExtents
bool hasKnownExtents
True if the results in each output bin fall within a fixed numeric range (minimum and maximum values)...
Definition vamp-sdk/Plugin.h:260
Vamp::Plugin::OutputDescriptor::hasFixedBinCount
bool hasFixedBinCount
True if the output has the same number of values per sample for every output sample.
Definition vamp-sdk/Plugin.h:239
Vamp::Plugin::OutputDescriptor::description
std::string description
A human-readable short text describing the output.
Definition vamp-sdk/Plugin.h:227
Vamp::Plugin::OutputDescriptor::binCount
size_t binCount
The number of values per result of the output.
Definition vamp-sdk/Plugin.h:247
Vamp::RealTime
RealTime represents time values to nanosecond precision with accurate arithmetic and frame-rate conve...
Definition vamp-sdk/RealTime.h:67