annotate 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.

#include <iostream>
#include <Python.h>
#include "../../src/OnsetDetectionFunction.h"
#include "../../src/BTrack.h"
#include <numpy/arrayobject.h>

//=======================================================================
static PyObject * btrack_onsetdf(PyObject *dummy, PyObject *args) 
{
    PyObject *arg1=NULL;
    PyObject *arr1=NULL;
    
    if (!PyArg_ParseTuple(args, "O", &arg1)) 
    {
        return NULL;
    }
    
    arr1 = PyArray_FROM_OTF(arg1, NPY_DOUBLE, NPY_IN_ARRAY); 
    if (arr1 == NULL) 
    {
        return NULL;
    }


    
    ////////// GET INPUT DATA ///////////////////
    
    // get data as array
    double* data = (double*) PyArray_DATA(arr1);
    
    // get array size
    long signal_length = PyArray_Size((PyObject*)arr1);
    
    ////////// BEGIN PROCESS ///////////////////
    int hopSize = 512;
    int frameSize = 1024;
    int df_type = 6;
    int numframes;
    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) hopSize));
    
    OnsetDetectionFunction onset(hopSize,frameSize,df_type,1);

    double df[numframes];
    

    
    ///////////////////////////////////////////
	//////// Begin Processing Loop ////////////
	
	for (int i=0;i < numframes;i++)
	{		
		// add new samples to frame
		for (int n = 0;n < hopSize;n++)
		{
			buffer[n] = data[(i*hopSize)+n];
		}
		
		df[i] = onset.getDFsample(buffer);
		
	}
	
	///////// End Processing Loop /////////////
	///////////////////////////////////////////
    
    
    ////////// END PROCESS ///////////////////
    
    
    
    ////////// CREATE ARRAY AND RETURN IT ///////////////////
    int nd=1;
    npy_intp m= numframes;
    //double fArray[5] = {0,1,2,3,4};
    
    PyObject* c=PyArray_SimpleNew(nd, &m, NPY_DOUBLE);
    
    void *arr_data = PyArray_DATA((PyArrayObject*)c);
        
    memcpy(arr_data, df, PyArray_ITEMSIZE((PyArrayObject*) c) * m); 
    
     
    Py_DECREF(arr1);  
    Py_INCREF(Py_None); 
    //return Py_None;
    
    return (PyObject *)c;
}

//=======================================================================
static PyObject * btrack_btrack(PyObject *dummy, PyObject *args) 
{
    PyObject *arg1=NULL;
    PyObject *arr1=NULL;
    
    if (!PyArg_ParseTuple(args, "O", &arg1)) 
    {
        return NULL;
    }
    
    arr1 = PyArray_FROM_OTF(arg1, NPY_DOUBLE, NPY_IN_ARRAY); 
    if (arr1 == NULL) 
    {
        return NULL;
    }
    
    
    
    ////////// GET INPUT DATA ///////////////////
    
    // get data as array
    double* data = (double*) PyArray_DATA(arr1);
    
    // get array size
    long signal_length = PyArray_Size((PyObject*)arr1);

    
    ////////// BEGIN PROCESS ///////////////////
    int hopSize = 512;
    int frameSize = 1024;

    int numframes;
    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) hopSize));
    

    BTrack b(hopSize,frameSize);
    
    
    double beats[5000];
    int beatnum = 0;
    
    ///////////////////////////////////////////
	//////// Begin Processing Loop ////////////
	
	for (int i=0;i < numframes;i++)
	{		
		// add new samples to frame
		for (int n = 0;n < hopSize;n++)
		{
			buffer[n] = data[(i*hopSize)+n];
		}
		
        // process the current audio frame
        b.processAudioFrame(buffer);
        
        // if a beat is currently scheduled
		if (b.playbeat == 1)
		{
			//beats[beatnum] = (((double) hopSize) / 44100) * ((double) i);
			beats[beatnum] = BTrack::getBeatTimeInSeconds(i,hopSize,44100);
            beatnum = beatnum + 1;
		}
		
	}
	
	///////// End Processing Loop /////////////
	///////////////////////////////////////////
    
    
    ////////// END PROCESS ///////////////////
    
    double beats_out[beatnum];          // create output array
    
    // copy beats into output array
    for (int i = 0;i < beatnum;i++)     
    {
        beats_out[i] = beats[i];
    }
    
    
    
    ////////// CREATE ARRAY AND RETURN IT ///////////////////
    int nd=1;
    npy_intp m= beatnum;
    //double fArray[5] = {0,1,2,3,4};
    
    PyObject* c=PyArray_SimpleNew(nd, &m, NPY_DOUBLE);
    
    void *arr_data = PyArray_DATA((PyArrayObject*)c);
    
    memcpy(arr_data, beats_out, PyArray_ITEMSIZE((PyArrayObject*) c) * m); 
    
    
    Py_DECREF(arr1);  
    Py_INCREF(Py_None); 
    //return Py_None;
    
    return (PyObject *)c;
}

//=======================================================================
static PyObject * btrack_btrack_df(PyObject *dummy, PyObject *args) 
{
    PyObject *arg1=NULL;
    PyObject *arr1=NULL;
    
    if (!PyArg_ParseTuple(args, "O", &arg1)) 
    {
        return NULL;
    }
    
    arr1 = PyArray_FROM_OTF(arg1, NPY_DOUBLE, NPY_IN_ARRAY); 
    if (arr1 == NULL) 
    {
        return NULL;
    }
    
    
    
    ////////// GET INPUT DATA ///////////////////
    
    // get data as array
    double* data = (double*) PyArray_DATA(arr1);
    
    // get array size
    long numframes = PyArray_Size((PyObject*)arr1);

    ////////// BEGIN PROCESS ///////////////////
    int hopSize = 512;
    int frameSize = 2*hopSize;

    BTrack b(hopSize,frameSize);
    
    double beats[5000];
    int beatnum = 0;
    double df_val;
    
    ///////////////////////////////////////////
	//////// Begin Processing Loop ////////////
	
	for (long i=0;i < numframes;i++)
	{		
        df_val = data[i] + 0.0001;
        
		b.processOnsetDetectionFunctionSample(df_val);				// process df sample in beat tracker
		
		if (b.playbeat == 1)
		{
			//beats[beatnum] = (((double) hopSize) / 44100) * ((double) i);
            beats[beatnum] = BTrack::getBeatTimeInSeconds(i,hopSize,44100);
			beatnum = beatnum + 1;	
		}
		
	}
	
	///////// End Processing Loop /////////////
	///////////////////////////////////////////
    
    
    ////////// END PROCESS ///////////////////
    
    double beats_out[beatnum];          // create output array
    
    
    // copy beats into output array
    for (int i = 0;i < beatnum;i++)     
    {
        beats_out[i] = beats[i];
    }
    
    
    ////////// CREATE ARRAY AND RETURN IT ///////////////////
    int nd=1;
    npy_intp m= beatnum;
    //double fArray[5] = {0,1,2,3,4};
    
    PyObject* c=PyArray_SimpleNew(nd, &m, NPY_DOUBLE);
    
    void *arr_data = PyArray_DATA((PyArrayObject*)c);
    
    memcpy(arr_data, beats_out, PyArray_ITEMSIZE((PyArrayObject*) c) * m); 
    
    
    Py_DECREF(arr1);  
    Py_INCREF(Py_None); 
    //return Py_None;
    
    return (PyObject *)c;
}


//=======================================================================
static PyMethodDef btrack_methods[] = {
    { "onsetdf",btrack_onsetdf,METH_VARARGS,"onset detection function"},
    { "btrack",btrack_btrack,METH_VARARGS,"beat tracker"},
    { "btrack_df",btrack_btrack_df,METH_VARARGS,"beat tracker with detection function input"},
    {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 */
    Py_SetProgramName(argv[0]);
    
    /* Initialize the Python interpreter.  Required. */
    Py_Initialize();
    
    /* Add a static module */
    initbtrack();
}