ref: 992beaa9bea5d3cd1aae961f80f581d2003bcc79
dir: /src/onset/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 "fvec.h"
#include "mathutils.h"
#include "lvec.h"
#include "temporal/filter.h"
#include "temporal/biquad.h"
#include "onset/peakpick.h"
/* peak picking parameters, default values in brackets
*
* [<----post----|--pre-->]
* .................|.............
* time-> ^now
*/
struct _aubio_peakpicker_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_filter_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;
/** number of channels to analyse */
uint_t channels;
/** \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 */
void
aubio_peakpicker_do (aubio_peakpicker_t * p, fvec_t * onset, fvec_t * out)
{
fvec_t *onset_keep = p->onset_keep;
fvec_t *onset_proc = p->onset_proc;
fvec_t *onset_peek = p->onset_peek;
fvec_t *scratch = p->scratch;
smpl_t mean = 0., median = 0.;
uint_t length = p->win_post + p->win_pre + 1;
uint_t i, j = 0;
for (i = 0; i < p->channels; i++) {
/* store onset in onset_keep */
/* shift all elements but last, then write last */
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_filter_do_filtfilt (p->biquad, onset_proc, scratch);
for (i = 0; i < p->channels; i++) {
/* calculate mean and median for onset_proc */
mean = fvec_mean_channel (onset_proc, i);
/* copy to scratch */
for (j = 0; j < length; j++)
scratch->data[i][j] = onset_proc->data[i][j];
median = p->thresholdfn (scratch, 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;
out->data[i][0] = (p->pickerfn) (onset_peek, 1);
if (out->data[i][0]) {
out->data[i][0] = fvec_quadint (onset_peek, 1, i);
}
}
}
/** this method returns the current value in the pick peaking buffer
* after smoothing
*/
smpl_t aubio_peakpicker_get_thresholded_input(aubio_peakpicker_t * p)
{
return p->onset_peek->data[0][1];
}
uint_t aubio_peakpicker_set_threshold(aubio_peakpicker_t * p, smpl_t threshold) {
p->threshold = threshold;
return AUBIO_OK;
}
smpl_t aubio_peakpicker_get_threshold(aubio_peakpicker_t * p) {
return p->threshold;
}
uint_t aubio_peakpicker_set_thresholdfn(aubio_peakpicker_t * p, aubio_thresholdfn_t thresholdfn) {
p->thresholdfn = thresholdfn;
return AUBIO_OK;
}
aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn(aubio_peakpicker_t * p) {
return (aubio_thresholdfn_t) (p->thresholdfn);
}
aubio_peakpicker_t * new_aubio_peakpicker(uint_t channels) {
aubio_peakpicker_t * t = AUBIO_NEW(aubio_peakpicker_t);
t->threshold = 0.1; /* 0.0668; 0.33; 0.082; 0.033; */
t->win_post = 5;
t->win_pre = 1;
//channels = 1;
t->channels = channels;
t->thresholdfn = (aubio_thresholdfn_t)(fvec_median_channel); /* (fvec_mean); */
t->pickerfn = (aubio_pickerfn_t)(fvec_peakpick);
t->scratch = new_fvec(t->win_post+t->win_pre+1, channels);
t->onset_keep = new_fvec(t->win_post+t->win_pre+1, channels);
t->onset_proc = new_fvec(t->win_post+t->win_pre+1, channels);
t->onset_peek = new_fvec(3, channels);
/* cutoff: low-pass filter with cutoff reduced frequency at 0.34
generated with octave butter function: [b,a] = butter(2, 0.34);
*/
t->biquad = new_aubio_filter_biquad (0.15998789, 0.31997577, 0.15998789,
-0.59488894, 0.23484048, channels);
return t;
}
void del_aubio_peakpicker(aubio_peakpicker_t * p) {
del_aubio_filter(p->biquad);
del_fvec(p->onset_keep);
del_fvec(p->onset_proc);
del_fvec(p->onset_peek);
del_fvec(p->scratch);
AUBIO_FREE(p);
}