diff modules-and-plug-ins/python-module/btrack_python_module.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/modules-and-plug-ins/python-module/btrack_python_module.cpp	Wed Jan 22 02:49:29 2014 +0000
+++ b/modules-and-plug-ins/python-module/btrack_python_module.cpp	Wed Jan 22 18:47:16 2014 +0000
@@ -4,6 +4,7 @@
 #include "../../src/BTrack.h"
 #include <numpy/arrayobject.h>
 
+//=======================================================================
 static PyObject * btrack_onsetdf(PyObject *dummy, PyObject *args) 
 {
     PyObject *arg1=NULL;
@@ -29,23 +30,19 @@
     
     // get array size
     long signal_length = PyArray_Size((PyObject*)arr1);
-    //int k = (int) theSize;
-    
-    // get data type 
-    //char type = PyArray_DESCR(arr1)->type;
     
     ////////// BEGIN PROCESS ///////////////////
-    int hsize = 512;
-    int fsize = 1024;
+    int hopSize = 512;
+    int frameSize = 1024;
     int df_type = 6;
     int numframes;
-    double buffer[hsize];	// buffer to hold one hopsize worth of audio samples
+    double buffer[hopSize];	// buffer to hold one hopsize worth of audio samples
 
     
     // get number of audio frames, given the hop size and signal length
-	numframes = (int) floor(((double) signal_length) / ((double) hsize));
+	numframes = (int) floor(((double) signal_length) / ((double) hopSize));
     
-    OnsetDetectionFunction onset(hsize,fsize,df_type,1);
+    OnsetDetectionFunction onset(hopSize,frameSize,df_type,1);
 
     double df[numframes];
     
@@ -57,9 +54,9 @@
 	for (int i=0;i < numframes;i++)
 	{		
 		// add new samples to frame
-		for (int n = 0;n < hsize;n++)
+		for (int n = 0;n < hopSize;n++)
 		{
-			buffer[n] = data[(i*hsize)+n];
+			buffer[n] = data[(i*hopSize)+n];
 		}
 		
 		df[i] = onset.getDFsample(buffer);
@@ -91,19 +88,9 @@
     //return Py_None;
     
     return (PyObject *)c;
-    
-    //return Py_BuildValue("c", type);
-    //return Py_BuildValue("d", sum);
-    //return Py_BuildValue("i", k);
-/*    
-fail:
-    Py_XDECREF(arr1); 
-    Py_XDECREF(arr2); 
-    PyArray_XDECREF_ERR(oarr); 
-    return NULL;*/
 }
 
-
+//=======================================================================
 static PyObject * btrack_btrack(PyObject *dummy, PyObject *args) 
 {
     PyObject *arg1=NULL;
@@ -129,35 +116,25 @@
     
     // get array size
     long signal_length = PyArray_Size((PyObject*)arr1);
-    //int k = (int) theSize;
-    
-    // get data type 
-    //char type = PyArray_DESCR(arr1)->type;
+
     
     ////////// BEGIN PROCESS ///////////////////
-    int hsize = 512;
-    int fsize = 1024;
-    int df_type = 6;
+    int hopSize = 512;
+    int frameSize = 1024;
+
     int numframes;
-    double buffer[hsize];	// buffer to hold one hopsize worth of audio samples
+    double buffer[hopSize];	// buffer to hold one hopsize worth of audio samples
     
     
     // get number of audio frames, given the hop size and signal length
-	numframes = (int) floor(((double) signal_length) / ((double) hsize));
+	numframes = (int) floor(((double) signal_length) / ((double) hopSize));
     
-    OnsetDetectionFunction onset(hsize,fsize,df_type,1);
-    BTrack b;
+
+    BTrack b(hopSize,frameSize);
     
-    b.initialise((int) hsize);	// initialise beat tracker
-	
-	// set parameters
-    //b.setparams(0.9,5);
     
-    double df[numframes];
     double beats[5000];
     int beatnum = 0;
-
-    double df_val;
     
     ///////////////////////////////////////////
 	//////// Begin Processing Loop ////////////
@@ -165,21 +142,20 @@
 	for (int i=0;i < numframes;i++)
 	{		
 		// add new samples to frame
-		for (int n = 0;n < hsize;n++)
+		for (int n = 0;n < hopSize;n++)
 		{
-			buffer[n] = data[(i*hsize)+n];
+			buffer[n] = data[(i*hopSize)+n];
 		}
 		
-		df[i] = onset.getDFsample(buffer);
+        // process the current audio frame
+        b.processAudioFrame(buffer);
         
-        df_val = df[i] + 0.0001;
-                
-		b.process(df_val);				// process df sample in beat tracker
-		
+        // if a beat is currently scheduled
 		if (b.playbeat == 1)
 		{
-			beats[beatnum] = (((double) hsize) / 44100) * ((double) i);
-			beatnum = beatnum + 1;	
+			//beats[beatnum] = (((double) hopSize) / 44100) * ((double) i);
+			beats[beatnum] = BTrack::getBeatTimeInSeconds(i,hopSize,44100);
+            beatnum = beatnum + 1;
 		}
 		
 	}
@@ -217,18 +193,9 @@
     //return Py_None;
     
     return (PyObject *)c;
-    
-    //return Py_BuildValue("c", type);
-    //return Py_BuildValue("d", sum);
-    //return Py_BuildValue("i", k);
-    /*    
-     fail:
-     Py_XDECREF(arr1); 
-     Py_XDECREF(arr2); 
-     PyArray_XDECREF_ERR(oarr); 
-     return NULL;*/
 }
 
+//=======================================================================
 static PyObject * btrack_btrack_df(PyObject *dummy, PyObject *args) 
 {
     PyObject *arg1=NULL;
@@ -254,20 +221,12 @@
     
     // get array size
     long numframes = PyArray_Size((PyObject*)arr1);
-    //int k = (int) theSize;
-    
-    // get data type 
-    //char type = PyArray_DESCR(arr1)->type;
-    
+
     ////////// BEGIN PROCESS ///////////////////
-    int hsize = 512;
+    int hopSize = 512;
+    int frameSize = 2*hopSize;
 
-    BTrack b;
-    
-    b.initialise((int) hsize);	// initialise beat tracker
-	
-	// set parameters
-    //b.setparams(0.9,5);
+    BTrack b(hopSize,frameSize);
     
     double beats[5000];
     int beatnum = 0;
@@ -280,11 +239,12 @@
 	{		
         df_val = data[i] + 0.0001;
         
-		b.process(df_val);				// process df sample in beat tracker
+		b.processOnsetDetectionFunctionSample(df_val);				// process df sample in beat tracker
 		
 		if (b.playbeat == 1)
 		{
-			beats[beatnum] = (((double) hsize) / 44100) * ((double) i);
+			//beats[beatnum] = (((double) hopSize) / 44100) * ((double) i);
+            beats[beatnum] = BTrack::getBeatTimeInSeconds(i,hopSize,44100);
 			beatnum = beatnum + 1;	
 		}
 		
@@ -323,20 +283,10 @@
     //return Py_None;
     
     return (PyObject *)c;
-    
-    //return Py_BuildValue("c", type);
-    //return Py_BuildValue("d", sum);
-    //return Py_BuildValue("i", k);
-    /*    
-     fail:
-     Py_XDECREF(arr1); 
-     Py_XDECREF(arr2); 
-     PyArray_XDECREF_ERR(oarr); 
-     return NULL;*/
 }
 
 
-
+//=======================================================================
 static PyMethodDef btrack_methods[] = {
     { "onsetdf",btrack_onsetdf,METH_VARARGS,"onset detection function"},
     { "btrack",btrack_btrack,METH_VARARGS,"beat tracker"},
@@ -344,12 +294,14 @@
     {NULL, NULL, 0, NULL} /* Sentinel */
 };
 
+//=======================================================================
 PyMODINIT_FUNC initbtrack(void)
 {
     (void)Py_InitModule("btrack", btrack_methods);
     import_array();
 }
 
+//=======================================================================
 int main(int argc, char *argv[])
 {
     /* Pass argv[0] to the Python interpreter */