ref: 2a109e4ee1f09fe440cd0b776134440ad9dcd6bc
dir: /src/onset/peakpicker.c/
/*
Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
This file is part of aubio.
aubio 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 3 of the License, or
(at your option) any later version.
aubio 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 aubio. If not, see <http://www.gnu.org/licenses/>.
*/
#include "aubio_priv.h"
#include "fvec.h"
#include "mathutils.h"
#include "lvec.h"
#include "temporal/filter.h"
#include "temporal/biquad.h"
#include "onset/peakpicker.h"
/** function pointer to thresholding function */
typedef smpl_t (*aubio_thresholdfn_t)(fvec_t *input);
/** function pointer to peak-picking function */
typedef uint_t (*aubio_pickerfn_t)(fvec_t *input, uint_t pos);
/** set peak picker thresholding function */
uint_t aubio_peakpicker_set_thresholdfn(aubio_peakpicker_t * p, aubio_thresholdfn_t thresholdfn);
/** get peak picker thresholding function */
aubio_thresholdfn_t aubio_peakpicker_get_thresholdfn(aubio_peakpicker_t * p);
/* 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;
/** thresholded function */
fvec_t *thresholded;
/** 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 */
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 *thresholded = p->thresholded;
fvec_t *scratch = p->scratch;
smpl_t mean = 0., median = 0.;
uint_t length = p->win_post + p->win_pre + 1;
uint_t j = 0;
/* store onset in onset_keep */
/* shift all elements but last, then write last */
for (j = 0; j < length - 1; j++) {
onset_keep->data[j] = onset_keep->data[j + 1];
onset_proc->data[j] = onset_keep->data[j];
}
onset_keep->data[length - 1] = onset->data[0];
onset_proc->data[length - 1] = onset->data[0];
/* filter onset_proc */
/** \bug filtfilt calculated post+pre times, should be only once !? */
aubio_filter_do_filtfilt (p->biquad, onset_proc, scratch);
/* calculate mean and median for onset_proc */
mean = fvec_mean (onset_proc);
/* copy to scratch */
for (j = 0; j < length; j++)
scratch->data[j] = onset_proc->data[j];
median = p->thresholdfn (scratch);
/* shift peek array */
for (j = 0; j < 3 - 1; j++)
onset_peek->data[j] = onset_peek->data[j + 1];
/* calculate new tresholded value */
thresholded->data[0] =
onset_proc->data[p->win_post] - median - mean * p->threshold;
onset_peek->data[2] = thresholded->data[0];
out->data[0] = (p->pickerfn) (onset_peek, 1);
if (out->data[0]) {
out->data[0] = fvec_quadint (onset_peek, 1);
}
}
/** this method returns the current value in the pick peaking buffer
* after smoothing
*/
fvec_t *
aubio_peakpicker_get_thresholded_input (aubio_peakpicker_t * p)
{
return p->thresholded;
}
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 ()
{
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;
t->thresholdfn = (aubio_thresholdfn_t) (fvec_median); /* (fvec_mean); */
t->pickerfn = (aubio_pickerfn_t) (fvec_peakpick);
t->scratch = new_fvec (t->win_post + t->win_pre + 1);
t->onset_keep = new_fvec (t->win_post + t->win_pre + 1);
t->onset_proc = new_fvec (t->win_post + t->win_pre + 1);
t->onset_peek = new_fvec (3);
t->thresholded = new_fvec (1);
/* 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);
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->thresholded);
del_fvec (p->scratch);
AUBIO_FREE (p);
}