27319718b1f8/code-docs/PowerSpectrum_8cpp_source.html

 /* -*- 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 2008 QMUL.

     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 "PowerSpectrum.h"

 using std::string;
 using std::cerr;
 using std::endl;

 #include <math.h>

 PowerSpectrum::PowerSpectrum(float inputSampleRate) :
     Plugin(inputSampleRate),
     m_blockSize(0)
 {
 }

 PowerSpectrum::~PowerSpectrum()
 {
 }

 string
 PowerSpectrum::getIdentifier() const
 {
     return "powerspectrum";
 }

 string
 PowerSpectrum::getName() const
 {
     return "Simple Power Spectrum";
 }

 string
 PowerSpectrum::getDescription() const
 {
     return "Return the power spectrum of a signal";
 }

 string
 PowerSpectrum::getMaker() const
 {
     return "Vamp SDK Example Plugins";
 }

 int
 PowerSpectrum::getPluginVersion() const
 {
     return 1;
 }

 string
 PowerSpectrum::getCopyright() const
 {
     return "Freely redistributable (BSD license)";
 }

 bool
 PowerSpectrum::initialise(size_t channels, size_t, size_t blockSize)
 {
     if (channels < getMinChannelCount() ||
         channels > getMaxChannelCount()) return false;

     m_blockSize = blockSize;

     return true;
 }

 void
 PowerSpectrum::reset()
 {
 }

 PowerSpectrum::OutputList
 PowerSpectrum::getOutputDescriptors() const
 {
     OutputList list;

     OutputDescriptor d;
     d.identifier = "powerspectrum";
     d.name = "Power Spectrum";
     d.description = "Power values of the frequency spectrum bins calculated from the input signal";
     d.unit = "";
     d.hasFixedBinCount = true;
     if (m_blockSize == 0) {
         // Just so as not to return "1".  This is the bin count that
         // would result from a block size of 1024, which is a likely
         // default -- but the host should always set the block size
         // before querying the bin count for certain.
         d.binCount = 513;
     } else {
         d.binCount = m_blockSize / 2 + 1;
     }
     d.hasKnownExtents = false;
     d.isQuantized = false;
     d.sampleType = OutputDescriptor::OneSamplePerStep;
     list.push_back(d);

     return list;
 }

 PowerSpectrum::FeatureSet
 PowerSpectrum::process(const float *const *inputBuffers, Vamp::RealTime)
 {
     FeatureSet fs;

     if (m_blockSize == 0) {
         cerr << "ERROR: PowerSpectrum::process: Not initialised" << endl;
         return fs;
     }

     size_t n = m_blockSize / 2 + 1;
     const float *fbuf = inputBuffers[0];

     Feature feature;
     feature.hasTimestamp = false;
     feature.values.reserve(n); // optional

     for (size_t i = 0; i < n; ++i) {

         double real = fbuf[i * 2];
         double imag = fbuf[i * 2 + 1];

         feature.values.push_back(real * real + imag * imag);
     }

     fs[0].push_back(feature);

     return fs;
 }

 PowerSpectrum::FeatureSet
 PowerSpectrum::getRemainingFeatures()
 {
     return FeatureSet();
 }

Vamp::Plugin::OutputList
std::vector< OutputDescriptor > OutputList
Definition: vamp-sdk/Plugin.h:335

Chris@6: PowerSpectrum::~PowerSpectrum
virtual ~PowerSpectrum()
Definition: PowerSpectrum.cpp:51

Chris@6: PowerSpectrum::getName
std::string getName() const
Get a human-readable name or title of the plugin.
Definition: PowerSpectrum.cpp:62

Chris@6: PowerSpectrum.h

Chris@6: Vamp::Plugin::OutputDescriptor
Definition: vamp-sdk/Plugin.h:206

Chris@6: 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

Chris@6: PowerSpectrum::getPluginVersion
int getPluginVersion() const
Get the version number of the plugin.
Definition: PowerSpectrum.cpp:80

Chris@6: Vamp::Plugin::Feature::values
std::vector< float > values
Results for a single sample of this feature.
Definition: vamp-sdk/Plugin.h:382

Chris@6: Vamp::Plugin::FeatureSet
std::map< int, FeatureList > FeatureSet
Definition: vamp-sdk/Plugin.h:395

Chris@6: PowerSpectrum::getMaker
std::string getMaker() const
Get the name of the author or vendor of the plugin in human-readable form.
Definition: PowerSpectrum.cpp:74

Chris@6: Vamp::Plugin::OutputDescriptor::description
std::string description
A human-readable short text describing the output.
Definition: vamp-sdk/Plugin.h:227

Chris@6: Vamp::Plugin::OutputDescriptor::identifier
std::string identifier
The name of the output, in computer-usable form.
Definition: vamp-sdk/Plugin.h:214

Chris@6: PowerSpectrum::getIdentifier
std::string getIdentifier() const
Get the computer-usable name of the plugin.
Definition: PowerSpectrum.cpp:56

Chris@6: PowerSpectrum::process
FeatureSet process(const float *const *inputBuffers, Vamp::RealTime timestamp)
Process a single block of input data.
Definition: PowerSpectrum.cpp:136

Chris@6: Vamp::Plugin::Feature
Definition: vamp-sdk/Plugin.h:344

Chris@6: Vamp::Plugin::OutputDescriptor::unit
std::string unit
The unit of the output, in human-readable form.
Definition: vamp-sdk/Plugin.h:232

Chris@6: Vamp::Plugin::getMinChannelCount
virtual size_t getMinChannelCount() const
Get the minimum supported number of input channels.
Definition: vamp-sdk/Plugin.h:199

Chris@6: Vamp::Plugin::OutputDescriptor::name
std::string name
The human-readable name of the output.
Definition: vamp-sdk/Plugin.h:220

Chris@6: Vamp::Plugin::getMaxChannelCount
virtual size_t getMaxChannelCount() const
Get the maximum supported number of input channels.
Definition: vamp-sdk/Plugin.h:204

Chris@6: PowerSpectrum::getDescription
std::string getDescription() const
Get a human-readable description for the plugin, typically a line of text that may optionally be disp...
Definition: PowerSpectrum.cpp:68

Chris@6: Vamp::RealTime
RealTime represents time values to nanosecond precision with accurate arithmetic and frame-rate conve...
Definition: vamp-sdk/RealTime.h:66

Chris@6: Vamp::Plugin::Feature::hasTimestamp
bool hasTimestamp
True if an output feature has its own timestamp.
Definition: vamp-sdk/Plugin.h:352

Chris@6: PowerSpectrum::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, step size (window increment, in sample frames) and block size (window size, in sample frames).
Definition: PowerSpectrum.cpp:92

Chris@6: PowerSpectrum::getRemainingFeatures
FeatureSet getRemainingFeatures()
After all blocks have been processed, calculate and return any remaining features derived from the co...
Definition: PowerSpectrum.cpp:166

Chris@6: PowerSpectrum::getOutputDescriptors
OutputList getOutputDescriptors() const
Get the outputs of this plugin.
Definition: PowerSpectrum.cpp:108

Chris@6: Vamp::Plugin::OutputDescriptor::OneSamplePerStep
Results from each process() align with that call&#39;s block start.
Definition: vamp-sdk/Plugin.h:290

Chris@6: Vamp::Plugin::OutputDescriptor::binCount
size_t binCount
The number of values per result of the output.
Definition: vamp-sdk/Plugin.h:247

Chris@6: PowerSpectrum::reset
void reset()
Reset the plugin after use, to prepare it for another clean run.
Definition: PowerSpectrum.cpp:103

Chris@6: Vamp::Plugin::OutputDescriptor::isQuantized
bool isQuantized
True if the output values are quantized to a particular resolution.
Definition: vamp-sdk/Plugin.h:278

Chris@6: PowerSpectrum::m_blockSize
size_t m_blockSize
Definition: PowerSpectrum.h:76

Chris@6: PowerSpectrum::getCopyright
std::string getCopyright() const
Get the copyright statement or licensing summary for the plugin.
Definition: PowerSpectrum.cpp:86

Chris@6: PowerSpectrum::PowerSpectrum
PowerSpectrum(float inputSampleRate)
Definition: PowerSpectrum.cpp:45

Chris@6: Vamp::Plugin::OutputDescriptor::sampleType
SampleType sampleType
Positioning in time of the output results.
Definition: vamp-sdk/Plugin.h:302

Chris@6: 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

Chris@6: