source: src/onset/onsetdetection.c @ 0a257a6

/*
   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"

/** Energy based onset detection function 
 
  This function calculates the local energy of the input spectral frame.
  
  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_energy(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** High Frequency Content onset detection function
 
  This method computes the High Frequency Content (HFC) of the input spectral
  frame. The resulting function is efficient at detecting percussive onsets.

  Paul Masri. Computer modeling of Sound for Transformation and Synthesis of
  Musical Signal. PhD dissertation, University of Bristol, UK, 1996.
  
  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_hfc(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Complex Domain Method onset detection function 
 
  Christopher Duxbury, Mike E. Davies, and Mark B. Sandler. Complex domain
  onset detection for musical signals. In Proceedings of the Digital Audio
  Effects Conference, DAFx-03, pages 90-93, London, UK, 2003.

  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_complex(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Phase Based Method onset detection function 

  Juan-Pablo Bello, Mike P. Davies, and Mark B. Sandler. Phase-based note onset
  detection for music signals. In Proceedings of the IEEE International
  Conference on Acoustics Speech and Signal Processing, pages 441­444,
  Hong-Kong, 2003.

  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_phase(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Spectral difference method onset detection function 

  Jonhatan Foote and Shingo Uchihashi. The beat spectrum: a new approach to
  rhythm analysis. In IEEE International Conference on Multimedia and Expo
  (ICME 2001), pages 881­884, Tokyo, Japan, August 2001.

  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_specdiff(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Kullback-Liebler onset detection function 
  
  Stephen Hainsworth and Malcom Macleod. Onset detection in music audio
  signals. In Proceedings of the International Computer Music Conference
  (ICMC), Singapore, 2003.
  
  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_kl(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Modified Kullback-Liebler onset detection function 

  Paul Brossier, ``Automatic annotation of musical audio for interactive
  systems'', Chapter 2, Temporal segmentation, PhD thesis, Centre for Digital
  music, Queen Mary University of London, London, UK, 2006.

  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_mkl(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);
/** Spectral Flux 

  Simon Dixon, Onset Detection Revisited, in ``Proceedings of the 9th
  International Conference on Digital Audio Effects'' (DAFx-06), Montreal,
  Canada, 2006. 

  \param o onset detection object as returned by new_aubio_onsetdetection()
  \param fftgrain input spectral frame
  \param onset output onset detection function

*/
void aubio_onsetdetection_specflux(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);

/** onsetdetection types */
typedef enum {
        aubio_onset_energy,         /**< energy based */          
        aubio_onset_specdiff,       /**< spectral diff */         
        aubio_onset_hfc,            /**< high frequency content */
        aubio_onset_complex,        /**< complex domain */        
        aubio_onset_phase,          /**< phase fast */            
        aubio_onset_kl,             /**< Kullback Liebler */
        aubio_onset_mkl,            /**< modified Kullback Liebler */
        aubio_onset_specflux,       /**< spectral flux */
        aubio_onset_default = aubio_onset_hfc, /**< default mode, set to hfc */
} aubio_onsetdetection_type;

/** structure to store object state */
struct _aubio_onsetdetection_t {
  aubio_onsetdetection_type onset_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_do (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 (char_t * onset_mode, 
    uint_t size, uint_t channels){
  aubio_onsetdetection_t * o = AUBIO_NEW(aubio_onsetdetection_t);
  uint_t rsize = size/2+1;
  aubio_onsetdetection_type onset_type;
  if (strcmp (onset_mode, "energy") == 0)
      onset_type = aubio_onset_energy;
  else if (strcmp (onset_mode, "specdiff") == 0)
      onset_type = aubio_onset_specdiff;
  else if (strcmp (onset_mode, "hfc") == 0)
      onset_type = aubio_onset_hfc;
  else if (strcmp (onset_mode, "complexdomain") == 0)
      onset_type = aubio_onset_complex;
  else if (strcmp (onset_mode, "complex") == 0)
      onset_type = aubio_onset_complex;
  else if (strcmp (onset_mode, "phase") == 0)
      onset_type = aubio_onset_phase;
  else if (strcmp (onset_mode, "mkl") == 0)
      onset_type = aubio_onset_mkl;
  else if (strcmp (onset_mode, "kl") == 0)
      onset_type = aubio_onset_kl;
  else if (strcmp (onset_mode, "specflux") == 0)
      onset_type = aubio_onset_specflux;
  else if (strcmp (onset_mode, "default") == 0)
      onset_type = aubio_onset_default;
  else {
      AUBIO_ERR("unknown onset type.\n");
      onset_type = aubio_onset_default;
  }
  switch(onset_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(onset_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->onset_type = onset_type;
  return o;
}

void del_aubio_onsetdetection (aubio_onsetdetection_t *o){
  switch(o->onset_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);
}