BTrack - A Real-Time Beat Tracker: Main Page

@@ -119,84 +119,85 @@

51 TukeyWindow

52 };

54 class OnsetDetectionFunction

55 {

56 public:

64 OnsetDetectionFunction(int hopSize_,int frameSize_,int onsetDetectionFunctionType_,int windowType);

67 ~OnsetDetectionFunction();

70 void initialise(int hopSize_,int frameSize_,int onsetDetectionFunctionType_,int windowType);

73 double calculateOnsetDetectionFunctionSample(double *buffer);

76 void setOnsetDetectionFunctionType(int onsetDetectionFunctionType_);

78 private:

81 void performFFT();

83 //=======================================================================

85 double energyEnvelope();

88 double energyDifference();

54 //=======================================================================

56 class OnsetDetectionFunction

57 {

58 public:

66 OnsetDetectionFunction(int hopSize_,int frameSize_,int onsetDetectionFunctionType_,int windowType);

69 ~OnsetDetectionFunction();

77 void initialise(int hopSize_,int frameSize_,int onsetDetectionFunctionType_,int windowType);

83 double calculateOnsetDetectionFunctionSample(double *buffer);

88 void setOnsetDetectionFunctionType(int onsetDetectionFunctionType_);

91 double spectralDifference();

94 double spectralDifferenceHWR();

97 double phaseDeviation();

90 private:

93 void performFFT();

95 //=======================================================================

97 double energyEnvelope();

100 double complexSpectralDifference();

100 double energyDifference();

101

103 double complexSpectralDifferenceHWR();

103 double spectralDifference();

104

106 double highFrequencyContent();

106 double spectralDifferenceHWR();

107

109 double highFrequencySpectralDifference();

109 double phaseDeviation();

110

112 double highFrequencySpectralDifferenceHWR();

113

114 //=======================================================================

116 void calculateRectangularWindow();

117

119 void calculateHanningWindow();

120

122 void calclulateHammingWindow();

123

125 void calculateBlackmanWindow();

126

128 void calculateTukeyWindow();

129

130 //=======================================================================

132 double princarg(double phaseVal);

133

134

135 double pi;

137 int frameSize;

138 int hopSize;

139 int onsetDetectionFunctionType;

141 fftw_plan p;

142 fftw_complex *complexIn;

143 fftw_complex *complexOut;

145 int initialised;

147 double *frame;

148 double *window;

150 double prevEnergySum;

152 double *magSpec;

153 double *prevMagSpec;

155 double *phase;

156 double *prevPhase;

157 double *prevPhase2;

159 };

160

161

162 #endif

112 double complexSpectralDifference();

113

115 double complexSpectralDifferenceHWR();

116

118 double highFrequencyContent();

119

121 double highFrequencySpectralDifference();

122

124 double highFrequencySpectralDifferenceHWR();

125

126 //=======================================================================

128 void calculateRectangularWindow();

129

131 void calculateHanningWindow();

132

134 void calclulateHammingWindow();

135

137 void calculateBlackmanWindow();

138

140 void calculateTukeyWindow();

141

142 //=======================================================================

147 double princarg(double phaseVal);

148

149

150 double pi;

152 int frameSize;

153 int hopSize;

154 int onsetDetectionFunctionType;

156 fftw_plan p;

157 fftw_complex *complexIn;

158 fftw_complex *complexOut;

160 int initialised;

162 double *frame;

163 double *window;

165 double prevEnergySum;

167 double *magSpec;

168 double *prevMagSpec;

170 double *phase;

171 double *prevPhase;

172 double *prevPhase2;

174 };

175

176

177 #endif

+ +

#include <OnsetDetectionFunction.h>

@@ -100,7 +102,9 @@

Public Member Functions
void	setOnsetDetectionFunctionType (int onsetDetectionFunctionType_)

Constructor & Destructor Documentation

Detailed Description

A class for calculating onset detection functions.

Constructor & Destructor Documentation

@@ -179,7 +183,14 @@

process input frame and calculate detection function sample

Process input frame and calculate detection function sample

Parameters

+ + +

buffer a pointer to an array containing the audio samples to be processed

Returns: the onset detection function sample

@@ -219,6 +230,15 @@

A real-time beat tracker, implemented in C++.

Written by Adam Stark, Matthew Davies and Mark Plumbley.

License

BTrack is made available under the GNU General Public License, version 3. Please see the included LICENSE.txt for more details.

Usage - C++

STEP 1

Include the BTrack header file as follows:

    #include "BTrack.h"
+

STEP 2

Instantiate the algorithm by one of the following:

// to use the default 512 hop size and 1024 frame size
+BTrack b; 
+

or:

// to specify a hop size (e.g. 512) and have a frame size of 2 x the hop size
+BTrack b(512); 
+

or:

// to specify both the hop size and frame size
+BTrack b(512,1024);
+

STEP 3.1 - Audio Input

In the processing loop, fill a double precision array with one frame of audio samples (as determined in step 2):

double *frame; 
+
+// !
+// do something here to fill the frame with audio samples
+// !
+

and then call:

b.processAudioFrame(frame);
+

and to check for beats, simply call:

if (b.beatDueInCurrentFrame())
+{
+    // do something on the beat
+}
+

STEP 3.2 - Onset Detection Function Input

The algorithm can process onset detection function samples. Given a double precision onset detection function sample called 'newSamples', at each step, call:

b.processOnsetDetectionFunctionSample(newSample);
+

and then check for beats with:

if (b.beatDueInCurrentFrame())
+{
+    // do something on the beat
+}
+

For any questions, please email Adam Stark (email at http://www.adamstark.co.uk).

hopSize_	the hop size in audio samples
frameSize_	the frame size in audio samples
onsetDetectionFunctionType_	the type of onset detection function to use - (see OnsetDetectionFunctionType)
windowType	the type of window to use (see WindowType)

Public Member Functions

Constructor & Destructor Documentation

Detailed Description

Constructor & Destructor Documentation

License

Usage - C++