diff src/BTrack.cpp @ 18:450c53430540 develop

Changed the interface of the algorithm so that onset detection function samples are calculated internally. This makes the call to the algorithm for most cases much simpler. Also added a static function for calculating beat times in seconds based upon sampling frequency, hop size and the current frame number.

--- a/src/BTrack.cpp	Wed Jan 22 02:49:29 2014 +0000
+++ b/src/BTrack.cpp	Wed Jan 22 18:47:16 2014 +0000
@@ -24,11 +24,54 @@
 #include "BTrack.h"
 #include "samplerate.h"
 
+//=======================================================================
+BTrack::BTrack() : odf(512,1024,6,1)
+{
+    initialise(512, 1024);
+}
 
 //=======================================================================
-BTrack :: BTrack()
+BTrack::BTrack(int hopSize) : odf(hopSize,2*hopSize,6,1)
 {	
-	double rayparam = 43;
+    initialise(hopSize, 2*hopSize);
+}
+
+//=======================================================================
+BTrack::BTrack(int hopSize,int frameSize) : odf(hopSize,frameSize,6,1)
+{
+    initialise(hopSize, frameSize);
+}
+
+//=======================================================================
+BTrack::~BTrack()
+{	
+	
+}
+
+//=======================================================================
+double BTrack::getBeatTimeInSeconds(long frameNumber,int hopSize,int fs)
+{
+    double hop = (double) hopSize;
+    double samplingFrequency = (double) fs;
+    double frameNum = (double) frameNumber;
+    
+    return ((hop / samplingFrequency) * frameNum);
+}
+
+//=======================================================================
+double BTrack::getBeatTimeInSeconds(int frameNumber,int hopSize,int fs)
+{
+    long frameNum = (long) frameNumber;
+    
+    return getBeatTimeInSeconds(frameNum, hopSize, fs);
+}
+
+
+
+//=======================================================================
+void BTrack::initialise(int hopSize, int frameSize)
+{
+    double rayparam = 43;
 	double pi = 3.14159265;
 	
 	
@@ -72,27 +115,22 @@
 			t_mu = i+1;
 			t_tmat[i][j] = (1 / (m_sig * sqrt(2*pi))) * exp( (-1*pow((x-t_mu),2)) / (2*pow(m_sig,2)) );
 		}
-	}	
+	}
 	
 	// tempo is not fixed
 	tempofix = 0;
+    
+    // initialise algorithm given the hopsize
+    setHopSize(hopSize);
 }
 
 //=======================================================================
-BTrack :: ~BTrack()
+void BTrack :: setHopSize(int hopSize)
 {	
+	framesize = hopSize;
+	dfbuffer_size = (512*512)/hopSize;		// calculate df buffer size
 	
-}
-
-
-
-//=======================================================================
-void BTrack :: initialise(int fsize)
-{	
-	framesize = fsize;
-	dfbuffer_size = (512*512)/fsize;		// calculate df buffer size
-	
-	bperiod = round(60/((((double) fsize)/44100)*tempo));
+	bperiod = round(60/((((double) hopSize)/44100)*tempo));
 	
 	dfbuffer = new double[dfbuffer_size];	// create df_buffer
 	cumscore = new double[dfbuffer_size];	// create cumscore
@@ -113,7 +151,21 @@
 }
 
 //=======================================================================
-void BTrack :: process(double df_sample)
+void BTrack::processAudioFrame(double *frame)
+{
+    // calculate the onset detection function sample for the frame
+    double sample = odf.getDFsample(frame);
+    
+    // add a tiny constant to the sample to stop it from ever going
+    // to zero. this is to avoid problems further down the line
+    sample = sample + 0.0001;
+    
+    // process the new onset detection function sample in the beat tracking algorithm
+    processOnsetDetectionFunctionSample(sample);
+}
+
+//=======================================================================
+void BTrack::processOnsetDetectionFunctionSample(double newSample)
 {	 
 	m0--;
 	beat--;
@@ -126,10 +178,10 @@
 	}
 	
 	// add new sample at the end
-	dfbuffer[dfbuffer_size-1] = df_sample;	
+	dfbuffer[dfbuffer_size-1] = newSample;
 	
 	// update cumulative score
-	updatecumscore(df_sample);
+	updatecumscore(newSample);
 	
 	// if we are halfway between beats
 	if (m0 == 0)