ref: 1e20c3f49d0624025c81e8b255edc8e7aa69ff00
dir: /src/pitch/pitchyinfft.c/
/*
Copyright (C) 2003-2013 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 "cvec.h"
#include "mathutils.h"
#include "spectral/fft.h"
#include "pitch/pitchyinfft.h"
/** pitch yinfft structure */
struct _aubio_pitchyinfft_t
{
fvec_t *win; /**< temporal weighting window */
fvec_t *winput; /**< windowed spectrum */
fvec_t *sqrmag; /**< square difference function */
fvec_t *weight; /**< spectral weighting window (psychoacoustic model) */
fvec_t *fftout; /**< Fourier transform output */
aubio_fft_t *fft; /**< fft object to compute square difference function */
fvec_t *yinfft; /**< Yin function */
smpl_t tol; /**< Yin tolerance */
smpl_t confidence; /**< confidence */
uint_t short_period; /** shortest period under which to check for octave error */
};
static const smpl_t freqs[] = {
0., 20., 25., 31.5, 40., 50., 63., 80., 100., 125.,
160., 200., 250., 315., 400., 500., 630., 800., 1000., 1250.,
1600., 2000., 2500., 3150., 4000., 5000., 6300., 8000., 9000., 10000.,
12500., 15000., 20000., 25100
};
static const smpl_t weight[] = {
-75.8, -70.1, -60.8, -52.1, -44.2, -37.5, -31.3, -25.6, -20.9, -16.5,
-12.6, -9.60, -7.00, -4.70, -3.00, -1.80, -0.80, -0.20, -0.00, 0.50,
1.60, 3.20, 5.40, 7.80, 8.10, 5.30, -2.40, -11.1, -12.8, -12.2,
-7.40, -17.8, -17.8, -17.8
};
aubio_pitchyinfft_t *
new_aubio_pitchyinfft (uint_t samplerate, uint_t bufsize)
{
uint_t i = 0, j = 1;
smpl_t freq = 0, a0 = 0, a1 = 0, f0 = 0, f1 = 0;
aubio_pitchyinfft_t *p = AUBIO_NEW (aubio_pitchyinfft_t);
p->winput = new_fvec (bufsize);
p->fft = new_aubio_fft (bufsize);
p->fftout = new_fvec (bufsize);
p->sqrmag = new_fvec (bufsize);
p->yinfft = new_fvec (bufsize / 2 + 1);
p->tol = 0.85;
p->win = new_aubio_window ("hanningz", bufsize);
p->weight = new_fvec (bufsize / 2 + 1);
for (i = 0; i < p->weight->length; i++) {
freq = (smpl_t) i / (smpl_t) bufsize *(smpl_t) samplerate;
while (freq > freqs[j]) {
j += 1;
}
a0 = weight[j - 1];
f0 = freqs[j - 1];
a1 = weight[j];
f1 = freqs[j];
if (f0 == f1) { // just in case
p->weight->data[i] = a0;
} else if (f0 == 0) { // y = ax+b
p->weight->data[i] = (a1 - a0) / f1 * freq + a0;
} else {
p->weight->data[i] = (a1 - a0) / (f1 - f0) * freq +
(a0 - (a1 - a0) / (f1 / f0 - 1.));
}
while (freq > freqs[j]) {
j += 1;
}
//AUBIO_DBG("%f\n",p->weight->data[i]);
p->weight->data[i] = DB2LIN (p->weight->data[i]);
//p->weight->data[i] = SQRT(DB2LIN(p->weight->data[i]));
}
// check for octave errors above 1300 Hz
p->short_period = (uint_t)ROUND(samplerate / 1300.);
return p;
}
void
aubio_pitchyinfft_do (aubio_pitchyinfft_t * p, const fvec_t * input, fvec_t * output)
{
uint_t tau, l;
uint_t length = p->fftout->length;
uint_t halfperiod;
fvec_t *fftout = p->fftout;
fvec_t *yin = p->yinfft;
smpl_t tmp = 0., sum = 0.;
// window the input
fvec_weighted_copy(input, p->win, p->winput);
// get the real / imag parts of its fft
aubio_fft_do_complex (p->fft, p->winput, fftout);
// get the squared magnitude spectrum, applying some weight
p->sqrmag->data[0] = SQR(fftout->data[0]);
p->sqrmag->data[0] *= p->weight->data[0];
for (l = 1; l < length / 2; l++) {
p->sqrmag->data[l] = SQR(fftout->data[l]) + SQR(fftout->data[length - l]);
p->sqrmag->data[l] *= p->weight->data[l];
p->sqrmag->data[length - l] = p->sqrmag->data[l];
}
p->sqrmag->data[length / 2] = SQR(fftout->data[length / 2]);
p->sqrmag->data[length / 2] *= p->weight->data[length / 2];
// get sum of weighted squared mags
for (l = 0; l < length / 2 + 1; l++) {
sum += p->sqrmag->data[l];
}
sum *= 2.;
// get the real / imag parts of the fft of the squared magnitude
aubio_fft_do_complex (p->fft, p->sqrmag, fftout);
yin->data[0] = 1.;
for (tau = 1; tau < yin->length; tau++) {
// compute the square differences
yin->data[tau] = sum - fftout->data[tau];
// and the cumulative mean normalized difference function
tmp += yin->data[tau];
if (tmp != 0) {
yin->data[tau] *= tau / tmp;
} else {
yin->data[tau] = 1.;
}
}
// find best candidates
tau = fvec_min_elem (yin);
if (yin->data[tau] < p->tol) {
// no interpolation, directly return the period as an integer
//output->data[0] = tau;
//return;
// 3 point quadratic interpolation
//return fvec_quadratic_peak_pos (yin,tau,1);
/* additional check for (unlikely) octave doubling in higher frequencies */
if (tau > p->short_period) {
output->data[0] = fvec_quadratic_peak_pos (yin, tau);
} else {
/* should compare the minimum value of each interpolated peaks */
halfperiod = FLOOR (tau / 2 + .5);
if (yin->data[halfperiod] < p->tol)
output->data[0] = fvec_quadratic_peak_pos (yin, halfperiod);
else
output->data[0] = fvec_quadratic_peak_pos (yin, tau);
}
} else {
output->data[0] = 0.;
}
}
void
del_aubio_pitchyinfft (aubio_pitchyinfft_t * p)
{
del_fvec (p->win);
del_aubio_fft (p->fft);
del_fvec (p->yinfft);
del_fvec (p->sqrmag);
del_fvec (p->fftout);
del_fvec (p->winput);
del_fvec (p->weight);
AUBIO_FREE (p);
}
smpl_t
aubio_pitchyinfft_get_confidence (aubio_pitchyinfft_t * o) {
o->confidence = 1. - fvec_min (o->yinfft);
return o->confidence;
}
uint_t
aubio_pitchyinfft_set_tolerance (aubio_pitchyinfft_t * p, smpl_t tol)
{
p->tol = tol;
return 0;
}
smpl_t
aubio_pitchyinfft_get_tolerance (aubio_pitchyinfft_t * p)
{
return p->tol;
}