source: src/onset/onsetdetection.c @ eb089fb

/*
   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 "fvec.h"
#include "cvec.h"
#include "spectral/fft.h"
#include "mathutils.h"
#include "utils/hist.h"
#include "onset/onsetdetection.h"


/** structure to store object state */
struct _aubio_onsetdetection_t {
  aubio_onsetdetection_type type; /**< onset detection type */
  /** Pointer to aubio_onsetdetection_<type> function */
  void (*funcpointer)(aubio_onsetdetection_t *o,
      cvec_t * fftgrain, fvec_t * onset);
  smpl_t threshold;      /**< minimum norm threshold for phase and specdiff */
  fvec_t *oldmag;        /**< previous norm vector */
  fvec_t *dev1 ;         /**< current onset detection measure vector */
  fvec_t *theta1;        /**< previous phase vector, one frame behind */
  fvec_t *theta2;        /**< previous phase vector, two frames behind */
  aubio_hist_t * histog; /**< histogram */
};


/* Energy based onset detection function */
void aubio_onsetdetection_energy  (aubio_onsetdetection_t *o UNUSED,
    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 UNUSED,
    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 */
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++)  {
      // compute the predicted phase
      o->dev1->data[i][j] = 2. * o->theta1->data[i][j] - o->theta2->data[i][j];
      // compute the euclidean distance in the complex domain
      // sqrt ( r_1^2 + r_2^2 - 2 * r_1 * r_2 * \cos ( \phi_1 - \phi_2 ) )
      onset->data[i][0] +=
        SQRT (ABS (SQR (o->oldmag->data[i][j]) + SQR (fftgrain->norm[i][j])
              - 2. * o->oldmag->data[i][j] * fftgrain->norm[i][j]
              * COS (o->dev1->data[i][j] - fftgrain->phas[i][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] = 0.0;
    o->dev1->data[i][0]=0.;
    for ( j=0;j<nbins; j++ )  {
      o->dev1->data[i][j] = 
        aubio_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] = 0.0;
      /* 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_weight(o->histog);
    /* its mean is the result */
    onset->data[i][0] = aubio_hist_mean(o->histog);  
    //onset->data[i][0] = fvec_mean(o->dev1);
  }
}

/* Spectral difference method onset detection function */
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] = 0.0;
    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] = 0.0;
      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_weight(o->histog);
    /* its mean is the result */
    onset->data[i][0] = aubio_hist_mean(o->histog);  

  }
}

/* Kullback Liebler onset detection function
 * note we use ln(1+Xn/(Xn-1+0.0001)) to avoid 
 * negative (1.+) and infinite values (+1.e-10) */
void aubio_onsetdetection_kl(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] += fftgrain->norm[i][j]
        *LOG(1.+fftgrain->norm[i][j]/(o->oldmag->data[i][j]+1.e-10));
      o->oldmag->data[i][j] = fftgrain->norm[i][j];
    }
    if (isnan(onset->data[i][0])) onset->data[i][0] = 0.;
  }
}

/* Modified Kullback Liebler onset detection function
 * note we use ln(1+Xn/(Xn-1+0.0001)) to avoid 
 * negative (1.+) and infinite values (+1.e-10) */
void aubio_onsetdetection_mkl(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] += LOG(1.+fftgrain->norm[i][j]/(o->oldmag->data[i][j]+1.e-10));
      o->oldmag->data[i][j] = fftgrain->norm[i][j];
    }
    if (isnan(onset->data[i][0])) onset->data[i][0] = 0.;
  }
}

/* Spectral flux */
void aubio_onsetdetection_specflux(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++) {
      if (fftgrain->norm[i][j] > o->oldmag->data[i][j])
        onset->data[i][0] += fftgrain->norm[i][j] - o->oldmag->data[i][j];
      o->oldmag->data[i][j] = fftgrain->norm[i][j];
    }
  }
}

/* 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 
 * depending on the choosen type, allocate memory as needed
 */
aubio_onsetdetection_t * 
new_aubio_onsetdetection (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;
  uint_t i;
  switch(type) {
    /* for both energy and hfc, only fftgrain->norm is required */
    case aubio_onset_energy: 
      break;
    case aubio_onset_hfc:
      break;
      /* the other approaches will need some more memory spaces */
    case aubio_onset_complex:
      o->oldmag = new_fvec(rsize,channels);
      o->dev1   = new_fvec(rsize,channels);
      o->theta1 = new_fvec(rsize,channels);
      o->theta2 = new_fvec(rsize,channels);
      break;
    case aubio_onset_phase:
      o->dev1   = new_fvec(rsize,channels);
      o->theta1 = new_fvec(rsize,channels);
      o->theta2 = new_fvec(rsize,channels);
      o->histog = new_aubio_hist(0.0, PI, 10, channels);
      o->threshold = 0.1;
      break;
    case aubio_onset_specdiff:
      o->oldmag = new_fvec(rsize,channels);
      o->dev1   = new_fvec(rsize,channels);
      o->histog = new_aubio_hist(0.0, PI, 10, channels);
      o->threshold = 0.1;
      break;
    case aubio_onset_kl:
    case aubio_onset_mkl:
    case aubio_onset_specflux:
      o->oldmag = new_fvec(rsize,channels);
      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 aubio_onset_energy:
      o->funcpointer = aubio_onsetdetection_energy;
      break;
    case aubio_onset_hfc:
      o->funcpointer = aubio_onsetdetection_hfc;
      break;
    case aubio_onset_complex:
      o->funcpointer = aubio_onsetdetection_complex;
      break;
    case aubio_onset_phase:
      o->funcpointer = aubio_onsetdetection_phase;
      break;
    case aubio_onset_specdiff:
      o->funcpointer = aubio_onsetdetection_specdiff;
      break;
    case aubio_onset_kl:
      o->funcpointer = aubio_onsetdetection_kl;
      break;
    case aubio_onset_mkl:
      o->funcpointer = aubio_onsetdetection_mkl;
      break;
    case aubio_onset_specflux:
      o->funcpointer = aubio_onsetdetection_specflux;
      break;
    default:
      break;
  }
  o->type = type;
  return o;
}

void del_aubio_onsetdetection (aubio_onsetdetection_t *o){
  switch(o->type) {
    /* for both energy and hfc, only fftgrain->norm is required */
    case aubio_onset_energy: 
      break;
    case aubio_onset_hfc:
      break;
      /* the other approaches will need some more memory spaces */
    case aubio_onset_complex:
      del_fvec(o->oldmag);
      del_fvec(o->dev1);
      del_fvec(o->theta1);
      del_fvec(o->theta2);
      break;
    case aubio_onset_phase:
      del_fvec(o->dev1);
      del_fvec(o->theta1);
      del_fvec(o->theta2);
      del_aubio_hist(o->histog);
      break;
    case aubio_onset_specdiff:
      del_fvec(o->oldmag);
      del_fvec(o->dev1);
      del_aubio_hist(o->histog);
      break;
    case aubio_onset_kl:
    case aubio_onset_mkl:
    case aubio_onset_specflux:
      del_fvec(o->oldmag);
      break;
    default:
      break;
  }
  AUBIO_FREE(o);
}