source: src/pitch/pitchyinfft.c @ 09558b8

yinfft+
Last change on this file since 09558b8 was 09558b8, checked in by Paul Brossier <piem@piem.org>, 4 years ago

src/pitch/pitchyinfft.c: simplify local peak lookup

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File size: 6.5 KB
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1/*
2  Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
3
4  This file is part of aubio.
5
6  aubio is free software: you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation, either version 3 of the License, or
9  (at your option) any later version.
10
11  aubio is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  GNU General Public License for more details.
15
16  You should have received a copy of the GNU General Public License
17  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
18
19*/
20
21#include "aubio_priv.h"
22#include "fvec.h"
23#include "cvec.h"
24#include "mathutils.h"
25#include "spectral/fft.h"
26#include "pitch/pitchyinfft.h"
27
28/** pitch yinfft structure */
29struct _aubio_pitchyinfft_t
30{
31  fvec_t *win;        /**< temporal weighting window */
32  fvec_t *winput;     /**< windowed spectrum */
33  fvec_t *sqrmag;     /**< square difference function */
34  fvec_t *weight;     /**< spectral weighting window (psychoacoustic model) */
35  fvec_t *fftout;     /**< Fourier transform output */
36  aubio_fft_t *fft;   /**< fft object to compute square difference function */
37  fvec_t *yinfft;     /**< Yin function */
38  smpl_t tol;         /**< Yin tolerance */
39  smpl_t confidence;  /**< confidence */
40  uint_t samplerate;  /**< samplerate we got initialized with */
41};
42
43static const smpl_t freqs[] = {
44     0.,    20.,    25.,   31.5,    40.,    50.,    63.,    80.,   100.,   125.,
45   160.,   200.,   250.,   315.,   400.,   500.,   630.,   800.,  1000.,  1250.,
46  1600.,  2000.,  2500.,  3150.,  4000.,  5000.,  6300.,  8000.,  9000., 10000.,
47 12500., 15000., 20000., 25100
48};
49
50static const smpl_t weight[] = {
51  -75.8,  -70.1,  -60.8,  -52.1,  -44.2,  -37.5,  -31.3,  -25.6,  -20.9,  -16.5,
52  -12.6,  -9.60,  -7.00,  -4.70,  -3.00,  -1.80,  -0.80,  -0.20,  -0.00,   0.50,
53   1.60,   3.20,   5.40,   7.80,   8.10,   5.30,  -2.40,  -11.1,  -12.8,  -12.2,
54  -7.40,  -17.8,  -17.8,  -17.8
55};
56
57aubio_pitchyinfft_t *
58new_aubio_pitchyinfft (uint_t samplerate, uint_t bufsize)
59{
60  uint_t i = 0, j = 1;
61  smpl_t freq = 0, a0 = 0, a1 = 0, f0 = 0, f1 = 0;
62  aubio_pitchyinfft_t *p = AUBIO_NEW (aubio_pitchyinfft_t);
63  p->winput = new_fvec (bufsize);
64  p->fft = new_aubio_fft (bufsize);
65  if (!p->fft) goto beach;
66  p->fftout = new_fvec (bufsize);
67  p->sqrmag = new_fvec (bufsize);
68  p->yinfft = new_fvec (bufsize / 2 + 1);
69  p->tol = 0.85;
70  p->win = new_aubio_window ("hanningz", bufsize);
71  p->weight = new_fvec (bufsize / 2 + 1);
72  p->samplerate = samplerate;
73  for (i = 0; i < p->weight->length; i++) {
74    freq = (smpl_t) i / (smpl_t) bufsize *(smpl_t) samplerate;
75    while (freq > freqs[j]) {
76      j += 1;
77    }
78    a0 = weight[j - 1];
79    f0 = freqs[j - 1];
80    a1 = weight[j];
81    f1 = freqs[j];
82    if (f0 == f1) {           // just in case
83      p->weight->data[i] = a0;
84    } else if (f0 == 0) {     // y = ax+b
85      p->weight->data[i] = (a1 - a0) / f1 * freq + a0;
86    } else {
87      p->weight->data[i] = (a1 - a0) / (f1 - f0) * freq +
88          (a0 - (a1 - a0) / (f1 / f0 - 1.));
89    }
90    while (freq > freqs[j]) {
91      j += 1;
92    }
93    //AUBIO_DBG("%f\n",p->weight->data[i]);
94    p->weight->data[i] = DB2LIN (p->weight->data[i]);
95    //p->weight->data[i] = SQRT(DB2LIN(p->weight->data[i]));
96  }
97
98  // disable weighting
99  fvec_set_all (p->weight, 1.0);
100
101  return p;
102
103beach:
104  if (p->winput) del_fvec(p->winput);
105  AUBIO_FREE(p);
106  return NULL;
107}
108
109void
110aubio_pitchyinfft_do (aubio_pitchyinfft_t * p, const fvec_t * input, fvec_t * output)
111{
112  uint_t tau, l;
113  uint_t length = p->fftout->length;
114  fvec_t *fftout = p->fftout;
115  fvec_t *yin = p->yinfft;
116  smpl_t tmp = 0., sum = 0.;
117  uint_t startbin = 0, endbin = 0, before = 0, after = 0;
118
119  // window the input
120  fvec_weighted_copy(input, p->win, p->winput);
121  // get the real / imag parts of its fft
122  aubio_fft_do_complex (p->fft, p->winput, fftout);
123  // get the squared magnitude spectrum, applying some weight
124  p->sqrmag->data[0] = SQR(fftout->data[0]);
125  p->sqrmag->data[0] *= p->weight->data[0];
126  for (l = 1; l < length / 2; l++) {
127    p->sqrmag->data[l] = SQR(fftout->data[l]) + SQR(fftout->data[length - l]);
128    p->sqrmag->data[l] *= p->weight->data[l];
129    p->sqrmag->data[length - l] = p->sqrmag->data[l];
130  }
131  p->sqrmag->data[length / 2] = SQR(fftout->data[length / 2]);
132  p->sqrmag->data[length / 2] *= p->weight->data[length / 2];
133  // get sum of weighted squared mags
134  for (l = 0; l < length / 2 + 1; l++) {
135    sum += p->sqrmag->data[l];
136  }
137  sum *= 2.;
138  // get the real / imag parts of the fft of the squared magnitude
139  aubio_fft_do_complex (p->fft, p->sqrmag, fftout);
140  yin->data[0] = 1.;
141  for (tau = 1; tau < yin->length; tau++) {
142    // compute the square differences
143    yin->data[tau] = sum - fftout->data[tau];
144    // and the cumulative mean normalized difference function
145    tmp += yin->data[tau];
146    if (tmp != 0) {
147      yin->data[tau] *= tau / tmp;
148    } else {
149      yin->data[tau] = 1.;
150    }
151  }
152
153  // calc min available confidence first
154  tmp = fvec_min(yin);
155  if (tmp > p->tol) {
156    // give up - got no confident candidate at all
157    output->data[0] = 0.;
158    return;
159  }
160
161  // choose lowest confident candidate first, to avoid choosing harmonics
162  tau = 0;
163  for (l = 1; l < yin->length; l++) {
164    // is this candidate "roughly" as good as the lowest one?
165    if (ABS (yin->data[l] - tmp) < 0.1) {
166      tau = l;
167      break;
168    }
169  }
170  // find local min around current pick to sharpen the results
171  before = 2, after = 5;
172  // for low frequency, the peak may be large, we use a larger after
173  if (tau > yin->length/2) { before = 1; after = 20; }
174  startbin = tau > before ? tau - before : 0;
175  endbin = tau < yin->length - 1 - after ? tau + after : yin->length - 1;
176  tmp = yin->data[tau];
177  for (l = startbin; l < endbin; l++) {
178    if (yin->data[l] < tmp ) {
179      tmp = yin->data[l];
180      tau = l;
181    }
182  }
183  output->data[0] = fvec_quadratic_peak_pos(yin, tau);
184}
185
186void
187del_aubio_pitchyinfft (aubio_pitchyinfft_t * p)
188{
189  del_fvec (p->win);
190  del_aubio_fft (p->fft);
191  del_fvec (p->yinfft);
192  del_fvec (p->sqrmag);
193  del_fvec (p->fftout);
194  del_fvec (p->winput);
195  del_fvec (p->weight);
196  AUBIO_FREE (p);
197}
198
199smpl_t
200aubio_pitchyinfft_get_confidence (aubio_pitchyinfft_t * o) {
201  o->confidence = 1. - fvec_min (o->yinfft);
202  return o->confidence;
203}
204
205uint_t
206aubio_pitchyinfft_set_tolerance (aubio_pitchyinfft_t * p, smpl_t tol)
207{
208  p->tol = tol;
209  return 0;
210}
211
212smpl_t
213aubio_pitchyinfft_get_tolerance (aubio_pitchyinfft_t * p)
214{
215  return p->tol;
216}
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