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VampPluginSDK Chris@6:  2.7 Chris@1:
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SpectralCentroid.cpp
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1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
2 
3 /*
4  Vamp
5 
6  An API for audio analysis and feature extraction plugins.
7 
8  Centre for Digital Music, Queen Mary, University of London.
9  Copyright 2006 Chris Cannam.
10 
11  Permission is hereby granted, free of charge, to any person
12  obtaining a copy of this software and associated documentation
13  files (the "Software"), to deal in the Software without
14  restriction, including without limitation the rights to use, copy,
15  modify, merge, publish, distribute, sublicense, and/or sell copies
16  of the Software, and to permit persons to whom the Software is
17  furnished to do so, subject to the following conditions:
18 
19  The above copyright notice and this permission notice shall be
20  included in all copies or substantial portions of the Software.
21 
22  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
26  ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
27  CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 
30  Except as contained in this notice, the names of the Centre for
31  Digital Music; Queen Mary, University of London; and Chris Cannam
32  shall not be used in advertising or otherwise to promote the sale,
33  use or other dealings in this Software without prior written
34  authorization.
35 */
36 
37 #include "SpectralCentroid.h"
38 
39 using std::string;
40 using std::vector;
41 using std::cerr;
42 using std::endl;
43 
44 #include <math.h>
45 
46 #ifdef __SUNPRO_CC
47 #include <ieeefp.h>
48 #define isinf(x) (!finite(x))
49 #endif
50 
51 #ifdef WIN32
52 #define isnan(x) false
53 #define isinf(x) false
54 #endif
55 
56 SpectralCentroid::SpectralCentroid(float inputSampleRate) :
57  Plugin(inputSampleRate),
58  m_stepSize(0),
59  m_blockSize(0)
60 {
61 }
62 
63 SpectralCentroid::~SpectralCentroid()
64 {
65 }
66 
67 string
68 SpectralCentroid::getIdentifier() const
69 {
70  return "spectralcentroid";
71 }
72 
73 string
74 SpectralCentroid::getName() const
75 {
76  return "Spectral Centroid";
77 }
78 
79 string
80 SpectralCentroid::getDescription() const
81 {
82  return "Calculate the centroid frequency of the spectrum of the input signal";
83 }
84 
85 string
86 SpectralCentroid::getMaker() const
87 {
88  return "Vamp SDK Example Plugins";
89 }
90 
91 int
92 SpectralCentroid::getPluginVersion() const
93 {
94  return 2;
95 }
96 
97 string
98 SpectralCentroid::getCopyright() const
99 {
100  return "Freely redistributable (BSD license)";
101 }
102 
103 bool
104 SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
105 {
106  if (channels < getMinChannelCount() ||
107  channels > getMaxChannelCount()) return false;
108 
109  m_stepSize = stepSize;
110  m_blockSize = blockSize;
111 
112  return true;
113 }
114 
115 void
116 SpectralCentroid::reset()
117 {
118 }
119 
120 SpectralCentroid::OutputList
121 SpectralCentroid::getOutputDescriptors() const
122 {
123  OutputList list;
124 
125  OutputDescriptor d;
126  d.identifier = "logcentroid";
127  d.name = "Log Frequency Centroid";
128  d.description = "Centroid of the log weighted frequency spectrum";
129  d.unit = "Hz";
130  d.hasFixedBinCount = true;
131  d.binCount = 1;
132  d.hasKnownExtents = false;
133  d.isQuantized = false;
134  d.sampleType = OutputDescriptor::OneSamplePerStep;
135  list.push_back(d);
136 
137  d.identifier = "linearcentroid";
138  d.name = "Linear Frequency Centroid";
139  d.description = "Centroid of the linear frequency spectrum";
140  list.push_back(d);
141 
142  return list;
143 }
144 
145 SpectralCentroid::FeatureSet
146 SpectralCentroid::process(const float *const *inputBuffers, Vamp::RealTime)
147 {
148  if (m_stepSize == 0) {
149  cerr << "ERROR: SpectralCentroid::process: "
150  << "SpectralCentroid has not been initialised"
151  << endl;
152  return FeatureSet();
153  }
154 
155  double numLin = 0.0, numLog = 0.0, denom = 0.0;
156 
157  for (size_t i = 1; i <= m_blockSize/2; ++i) {
158  double freq = (double(i) * m_inputSampleRate) / m_blockSize;
159  double real = inputBuffers[0][i*2];
160  double imag = inputBuffers[0][i*2 + 1];
161  double scalemag = sqrt(real * real + imag * imag) / (m_blockSize/2);
162  numLin += freq * scalemag;
163  numLog += log10f(freq) * scalemag;
164  denom += scalemag;
165  }
166 
167  FeatureSet returnFeatures;
168 
169  if (denom != 0.0) {
170  float centroidLin = float(numLin / denom);
171  float centroidLog = powf(10, float(numLog / denom));
172 
173  Feature feature;
174  feature.hasTimestamp = false;
175 
176  if (!isnan(centroidLog) && !isinf(centroidLog)) {
177  feature.values.push_back(centroidLog);
178  }
179  returnFeatures[0].push_back(feature);
180 
181  feature.values.clear();
182  if (!isnan(centroidLin) && !isinf(centroidLin)) {
183  feature.values.push_back(centroidLin);
184  }
185  returnFeatures[1].push_back(feature);
186  }
187 
188  return returnFeatures;
189 }
190 
191 SpectralCentroid::FeatureSet
192 SpectralCentroid::getRemainingFeatures()
193 {
194  return FeatureSet();
195 }
196 
Vamp::Plugin::OutputList
std::vector< OutputDescriptor > OutputList
Definition: vamp-sdk/Plugin.h:335
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SpectralCentroid::getCopyright
std::string getCopyright() const
Get the copyright statement or licensing summary for the plugin.
Definition: SpectralCentroid.cpp:98
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SpectralCentroid::getOutputDescriptors
OutputList getOutputDescriptors() const
Get the outputs of this plugin.
Definition: SpectralCentroid.cpp:121
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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
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Vamp::Plugin::Feature::values
std::vector< float > values
Results for a single sample of this feature.
Definition: vamp-sdk/Plugin.h:382
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Vamp::Plugin::FeatureSet
std::map< int, FeatureList > FeatureSet
Definition: vamp-sdk/Plugin.h:395
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SpectralCentroid::process
FeatureSet process(const float *const *inputBuffers, Vamp::RealTime timestamp)
Process a single block of input data.
Definition: SpectralCentroid.cpp:146
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SpectralCentroid::reset
void reset()
Reset the plugin after use, to prepare it for another clean run.
Definition: SpectralCentroid.cpp:116
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Vamp::Plugin::OutputDescriptor::description
std::string description
A human-readable short text describing the output.
Definition: vamp-sdk/Plugin.h:227
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SpectralCentroid::getName
std::string getName() const
Get a human-readable name or title of the plugin.
Definition: SpectralCentroid.cpp:74
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Vamp::Plugin::OutputDescriptor::identifier
std::string identifier
The name of the output, in computer-usable form.
Definition: vamp-sdk/Plugin.h:214
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SpectralCentroid::getPluginVersion
int getPluginVersion() const
Get the version number of the plugin.
Definition: SpectralCentroid.cpp:92
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Vamp::Plugin::m_inputSampleRate
float m_inputSampleRate
Definition: vamp-sdk/Plugin.h:444
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Vamp::Plugin::OutputDescriptor::unit
std::string unit
The unit of the output, in human-readable form.
Definition: vamp-sdk/Plugin.h:232
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Vamp::Plugin::getMinChannelCount
virtual size_t getMinChannelCount() const
Get the minimum supported number of input channels.
Definition: vamp-sdk/Plugin.h:199
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Vamp::Plugin::OutputDescriptor::name
std::string name
The human-readable name of the output.
Definition: vamp-sdk/Plugin.h:220
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Vamp::Plugin::getMaxChannelCount
virtual size_t getMaxChannelCount() const
Get the maximum supported number of input channels.
Definition: vamp-sdk/Plugin.h:204
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Vamp::RealTime
RealTime represents time values to nanosecond precision with accurate arithmetic and frame-rate conve...
Definition: vamp-sdk/RealTime.h:66
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Vamp::Plugin::Feature::hasTimestamp
bool hasTimestamp
True if an output feature has its own timestamp.
Definition: vamp-sdk/Plugin.h:352
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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
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SpectralCentroid::getIdentifier
std::string getIdentifier() const
Get the computer-usable name of the plugin.
Definition: SpectralCentroid.cpp:68
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SpectralCentroid::SpectralCentroid
SpectralCentroid(float inputSampleRate)
Definition: SpectralCentroid.cpp:56
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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
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SpectralCentroid::~SpectralCentroid
virtual ~SpectralCentroid()
Definition: SpectralCentroid.cpp:63
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Vamp::Plugin::OutputDescriptor::OneSamplePerStep
Results from each process() align with that call&#39;s block start.
Definition: vamp-sdk/Plugin.h:290
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Vamp::Plugin::OutputDescriptor::binCount
size_t binCount
The number of values per result of the output.
Definition: vamp-sdk/Plugin.h:247
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Vamp::Plugin::OutputDescriptor::isQuantized
bool isQuantized
True if the output values are quantized to a particular resolution.
Definition: vamp-sdk/Plugin.h:278
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Vamp::Plugin::OutputDescriptor::sampleType
SampleType sampleType
Positioning in time of the output results.
Definition: vamp-sdk/Plugin.h:302
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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, step size (window increment, in sample frames) and block size (window size, in sample frames).
Definition: SpectralCentroid.cpp:104
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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
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SpectralCentroid::getRemainingFeatures
FeatureSet getRemainingFeatures()
After all blocks have been processed, calculate and return any remaining features derived from the co...
Definition: SpectralCentroid.cpp:192
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