source: src/onsetdetection.c @ f382ac6

/*
   Copyright (C) 2003 Paul Brossier

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "aubio_priv.h"
#include "sample.h"
#include "fft.h"
#include "mathutils.h"
#include "hist.h"
#include "onsetdetection.h"


struct _aubio_onsetdetection_t {
        aubio_onsetdetection_type type;
        /** Pointer to aubio_onsetdetection_<type> function */
        void (*funcpointer)(aubio_onsetdetection_t *o,
                        cvec_t * fftgrain, fvec_t * onset);
        smpl_t threshold;
        fvec_t *oldmag;
        fft_data_t *meas;
        fvec_t *dev1 ;
        fvec_t *theta1;
        fvec_t *theta2;
        aubio_hist_t * histog;
};


static aubio_onsetdetection_t * aubio_onsetdetection_alloc(aubio_onsetdetection_type type, uint_t size, uint_t channels);

/* Energy based onset detection function */
void aubio_onsetdetection_energy  (aubio_onsetdetection_t *o,
                cvec_t * fftgrain, fvec_t * onset) {
        uint_t i,j;
        for (i=0;i<fftgrain->channels;i++) {
                onset->data[i][0] = 0.;
                for (j=0;j<fftgrain->length;j++) {
                        onset->data[i][0] += SQR(fftgrain->norm[i][j]);
                }
        }
}

/* High Frequency Content onset detection function */
void aubio_onsetdetection_hfc(aubio_onsetdetection_t *o,        cvec_t * fftgrain, fvec_t * onset){
        uint_t i,j;
        for (i=0;i<fftgrain->channels;i++) {
                onset->data[i][0] = 0.;
                for (j=0;j<fftgrain->length;j++) {
                        onset->data[i][0] += (j+1)*fftgrain->norm[i][j];
                }
        }
}


/* Complex Domain Method onset detection function */
/* moved to /2 032402 */
void aubio_onsetdetection_complex (aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset) {
        uint_t i, j;
        uint_t nbins = fftgrain->length;
        for (i=0;i<fftgrain->channels; i++)     {
                onset->data[i][0] = 0.;
                for (j=0;j<nbins; j++)  {
                        o->dev1->data[i][j]      = unwrap2pi(
                                        fftgrain->phas[i][j]
                                        -2.0*o->theta1->data[i][j]+
                                        o->theta2->data[i][j]);
                        o->meas[j] = fftgrain->norm[i][j]*CEXPC(I*o->dev1->data[i][j]);
                        /* sum on all bins */
                        onset->data[i][0]                += //(fftgrain->norm[i][j]);
                                        SQRT(SQR( REAL(o->oldmag->data[i][j]-o->meas[j]) )
                                                +  SQR( IMAG(o->oldmag->data[i][j]-o->meas[j]) )
                                                );
                        /* swap old phase data (need to remember 2 frames behind)*/
                        o->theta2->data[i][j] = o->theta1->data[i][j];
                        o->theta1->data[i][j] = fftgrain->phas[i][j];
                        /* swap old magnitude data (1 frame is enough) */
                        o->oldmag->data[i][j] = fftgrain->norm[i][j];
                }
        }
}


/* Phase Based Method onset detection function */
void aubio_onsetdetection_phase(aubio_onsetdetection_t *o, 
                cvec_t * fftgrain, fvec_t * onset){
        uint_t i, j;
        uint_t nbins = fftgrain->length;
        for (i=0;i<fftgrain->channels; i++)     {
                onset->data[i][0] = 0.0f;
                o->dev1->data[i][0]=0.;
                for ( j=0;j<nbins; j++ )        {
                        o->dev1->data[i][j] = 
                                unwrap2pi(
                                                fftgrain->phas[i][j]
                                                -2.0*o->theta1->data[i][j]
                                                +o->theta2->data[i][j]);
                        if ( o->threshold < fftgrain->norm[i][j] )
                                o->dev1->data[i][j] = ABS(o->dev1->data[i][j]);
                        else 
                                o->dev1->data[i][j] = 0.0f;
                        /* keep a track of the past frames */
                        o->theta2->data[i][j] = o->theta1->data[i][j];
                        o->theta1->data[i][j] = fftgrain->phas[i][j];
                }
                /* apply o->histogram */
                aubio_hist_dyn_notnull(o->histog,o->dev1);
                /* weight it */
                aubio_hist_weigth(o->histog);
                /* its mean is the result */
                onset->data[i][0] = aubio_hist_mean(o->histog); 
                //onset->data[i][0] = vec_mean(o->dev1);
        }
}

/* Spectral difference method onset detection function */
/* moved to /2 032402 */
void aubio_onsetdetection_specdiff(aubio_onsetdetection_t *o,
                cvec_t * fftgrain, fvec_t * onset){
        uint_t i, j;
        uint_t nbins = fftgrain->length;
        for (i=0;i<fftgrain->channels; i++)     {
                onset->data[i][0] = 0.0f;
                for (j=0;j<nbins; j++)  {
                        o->dev1->data[i][j] = SQRT(
                                        ABS(SQR( fftgrain->norm[i][j])
                                                - SQR(o->oldmag->data[i][j])));
                        if (o->threshold < fftgrain->norm[i][j] )
                                o->dev1->data[i][j] = ABS(o->dev1->data[i][j]);
                        else 
                                o->dev1->data[i][j] = 0.0f;
                        o->oldmag->data[i][j] = fftgrain->norm[i][j];
                }

                /* apply o->histogram (act somewhat as a low pass on the
                 * overall function)*/
                aubio_hist_dyn_notnull(o->histog,o->dev1);
                /* weight it */
                aubio_hist_weigth(o->histog);
                /* its mean is the result */
                onset->data[i][0] = aubio_hist_mean(o->histog); 

        }
}

/* Generic function pointing to the choosen one */
void 
aubio_onsetdetection(aubio_onsetdetection_t *o, cvec_t * fftgrain, 
                fvec_t * onset) {
        o->funcpointer(o,fftgrain,onset);
}

/* Allocate memory for an onset detection */
aubio_onsetdetection_t * 
new_aubio_onsetdetection (aubio_onsetdetection_type type, 
                uint_t size, uint_t channels){
        return aubio_onsetdetection_alloc(type,size,channels);
}

/* depending on the choosen type, allocate memory as needed */
aubio_onsetdetection_t * 
aubio_onsetdetection_alloc (aubio_onsetdetection_type type, 
                uint_t size, uint_t channels){
        aubio_onsetdetection_t * o = AUBIO_NEW(aubio_onsetdetection_t);
        uint_t rsize = size/2+1;
        switch(type) {
                /* for both energy and hfc, only fftgrain->norm is required */
                case energy: 
                        break;
                case hfc:
                        break;
                /* the other approaches will need some more memory spaces */
                case complexdomain:
                        o->oldmag = new_fvec(rsize,channels);
                        /** bug: must be complex array */
                        o->meas = AUBIO_ARRAY(fft_data_t,size);
                        o->dev1  = new_fvec(rsize,channels);
                        o->theta1 = new_fvec(rsize,channels);
                        o->theta2 = new_fvec(rsize,channels);
                        break;
                case phase:
                        o->dev1  = new_fvec(rsize,channels);
                        o->theta1 = new_fvec(rsize,channels);
                        o->theta2 = new_fvec(rsize,channels);
                        o->histog = new_aubio_hist(0.0f, PI, 10, channels);
                        o->threshold = 0.1;
                        break;
                case specdiff:
                        o->oldmag = new_fvec(rsize,channels);
                        o->dev1   = new_fvec(rsize,channels);
                        o->histog = new_aubio_hist(0.0f, PI, 10, channels);
                        o->threshold = 0.1;
                        break;
                default:
                        break;
        }
        
        /* this switch could be in its own function to change between
         * detections on the fly. this would need getting rid of the switch
         * above and always allocate all the structure */

        switch(type) {
                case energy:
                        o->funcpointer = aubio_onsetdetection_energy;
                        break;
                case hfc:
                        o->funcpointer = aubio_onsetdetection_hfc;
                        break;
                case complexdomain:
                        o->funcpointer = aubio_onsetdetection_complex;
                        break;
                case phase:
                        o->funcpointer = aubio_onsetdetection_phase;
                        break;
                case specdiff:
                        o->funcpointer = aubio_onsetdetection_specdiff;
                        break;
                default:
                        break;
        }
        o->type = type;
        return o;
}

void aubio_onsetdetection_free (aubio_onsetdetection_t *o){

        switch(o->type) {
                /* for both energy and hfc, only fftgrain->norm is required */
                case energy: 
                        break;
                case hfc:
                        break;
                /* the other approaches will need some more memory spaces */
                case complexdomain:
                        AUBIO_FREE(o->meas);
                        del_fvec(o->oldmag);
                        del_fvec(o->dev1);
                        del_fvec(o->theta1);
                        del_fvec(o->theta2);
                        break;
                case phase:
                        del_fvec(o->dev1);
                        del_fvec(o->theta1);
                        del_fvec(o->theta2);
                        del_aubio_hist(o->histog);
                        break;
                case specdiff:
                        del_fvec(o->oldmag);
                        del_fvec(o->dev1);
                        del_aubio_hist(o->histog);
                        break;
                default:
                        break;
        }
        AUBIO_FREE(o);
        
}