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peakpick.c

/*
   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 "mathutils.h"
#include "biquad.h"
#include "peakpick.h"

/* peak picking parameters, default values in brackets
 *
 *       [<----post----|--pre-->]
 *    .................|.............
 *    time->           ^now
 */
struct _aubio_pickpeak_t {
      /** thresh: offset threshold [0.033 or 0.01] */
      smpl_t threshold;       
      /** win_post: median filter window length (causal part) [8] */
      uint_t      win_post;               
      /** pre: median filter window (anti-causal part) [post-1] */
      uint_t      win_pre;                      
      /** threshfn: name or handle of fn for computing adaptive threshold [median]  */
      aubio_thresholdfn_t thresholdfn;
      /** picker: name or handle of fn for picking event times [peakpick] */
      aubio_pickerfn_t pickerfn;

      /** biquad lowpass filter */
      aubio_biquad_t * biquad;
      /** original onsets */
      fvec_t * onset_keep;
      /** modified onsets */
      fvec_t * onset_proc;
      /** peak picked window [3] */
      fvec_t * onset_peek;
      /** scratch pad for biquad and median */
      fvec_t * scratch;

      /** \bug should be used to calculate filter coefficients */
      /* cutoff: low-pass filter cutoff [0.34, 1] */
      /* smpl_t cutoff; */

      /* not used anymore */
      /* time precision [512/44100  winlength/samplerate, fs/buffer_size */
      /* smpl_t tau; */
      /* alpha: normalisation exponent [9] */
      /* smpl_t alpha; */
};


/** modified version for real time, moving mean adaptive threshold this method
 * is slightly more permissive than the offline one, and yelds to an increase
 * of false positives. best  */
00070 uint_t aubio_peakpick_pimrt(fvec_t * onset,  aubio_pickpeak_t * p) {
      fvec_t * onset_keep = (fvec_t *)p->onset_keep;
      fvec_t * onset_proc = (fvec_t *)p->onset_proc;
      fvec_t * onset_peek = (fvec_t *)p->onset_peek;
      fvec_t * scratch    = (fvec_t *)p->scratch;
      smpl_t mean = 0., median = 0.;
      uint_t length = p->win_post + p->win_pre + 1;
      uint_t i = 0, j;

      /* store onset in onset_keep */
      /* shift all elements but last, then write last */
      /* for (i=0;i<channels;i++) { */
      for (j=0;j<length-1;j++) {
            onset_keep->data[i][j] = onset_keep->data[i][j+1];
            onset_proc->data[i][j] = onset_keep->data[i][j];
      }
      onset_keep->data[i][length-1] = onset->data[i][0];
      onset_proc->data[i][length-1] = onset->data[i][0];
      /* } */

      /* filter onset_proc */
      /** \bug filtfilt calculated post+pre times, should be only once !? */
      aubio_biquad_do_filtfilt(p->biquad,onset_proc,scratch);

      /* calculate mean and median for onset_proc */
      /* for (i=0;i<onset_proc->channels;i++) { */
      mean = vec_mean(onset_proc);
      /* copy to scratch */
      for (j = 0; j < length; j++)
            scratch->data[i][j] = onset_proc->data[i][j];
      median = p->thresholdfn(scratch);
      /* } */

      /* for (i=0;i<onset->channels;i++) { */
      /* shift peek array */
      for (j=0;j<3-1;j++) 
            onset_peek->data[i][j] = onset_peek->data[i][j+1];
      /* calculate new peek value */
      onset_peek->data[i][2] = 
            onset_proc->data[i][p->win_post] - median - mean * p->threshold;
      /* } */
      //AUBIO_DBG("%f\n", onset_peek->data[0][2]);
      return (p->pickerfn)(onset_peek,1);
}

/** this method returns the current value in the pick peaking buffer
 * after smoothing
 */
00118 smpl_t aubio_peakpick_pimrt_getval(aubio_pickpeak_t * p) 
{
      uint_t i = 0;
      return p->onset_peek->data[i][1];
}

/** function added by Miguel Ramirez to return the onset detection amplitude in peakval */
00125 uint_t aubio_peakpick_pimrt_wt(fvec_t * onset,  aubio_pickpeak_t * p, smpl_t* peakval) 
{
      uint_t isonset = 0;
      isonset = aubio_peakpick_pimrt(onset,p);

      //if ( isonset && peakval != NULL )
      if ( peakval != NULL )
            *peakval = aubio_peakpick_pimrt_getval(p); 

      return isonset;
}

00137 void aubio_peakpicker_set_threshold(aubio_pickpeak_t * p, smpl_t threshold) {
      p->threshold = threshold;
      return;
}

00142 smpl_t aubio_peakpicker_get_threshold(aubio_pickpeak_t * p) {
      return p->threshold;
}

00146 void aubio_peakpicker_set_thresholdfn(aubio_pickpeak_t * p, aubio_thresholdfn_t thresholdfn) {
      p->thresholdfn = thresholdfn;
      return;
}

00151 aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn(aubio_pickpeak_t * p) {
      return (aubio_thresholdfn_t) (p->thresholdfn);
}

00155 aubio_pickpeak_t * new_aubio_peakpicker(smpl_t threshold) {
      aubio_pickpeak_t * t = AUBIO_NEW(aubio_pickpeak_t);
      t->threshold = 0.1; /* 0.0668; 0.33; 0.082; 0.033; */
      if (threshold > 0. && threshold < 10.)
            t->threshold = threshold;
      t->win_post  = 5;
      t->win_pre   = 1;

      t->thresholdfn = (aubio_thresholdfn_t)(vec_median); /* (vec_mean); */
      t->pickerfn = (aubio_pickerfn_t)(vec_peakpick);

      t->scratch = new_fvec(t->win_post+t->win_pre+1,1);
      t->onset_keep = new_fvec(t->win_post+t->win_pre+1,1);
      t->onset_proc = new_fvec(t->win_post+t->win_pre+1,1);
      t->onset_peek = new_fvec(3,1);

      /* cutoff: low-pass filter cutoff [0.34, 1] */
      /* t->cutoff=0.34; */
      t->biquad = new_aubio_biquad(0.1600,0.3200,0.1600,-0.5949,0.2348);
      return t;
}

00177 void del_aubio_peakpicker(aubio_pickpeak_t * p) {
      del_aubio_biquad(p->biquad);
      del_fvec(p->onset_keep);
      del_fvec(p->onset_proc);
      del_fvec(p->onset_peek);
      del_fvec(p->scratch);
      AUBIO_FREE(p);
}

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