source: src/pitchfcomb.c @ 1d4fc4a

feature/autosinkfeature/cnnfeature/cnn_orgfeature/constantqfeature/crepefeature/crepe_orgfeature/pitchshiftfeature/pydocstringsfeature/timestretchfix/ffmpeg5pitchshiftsamplertimestretchyinfft+
Last change on this file since 1d4fc4a was 1d4fc4a, checked in by Paul Brossier <piem@altern.org>, 18 years ago

add windowing, correct phase interpolation
add windowing, correct phase interpolation

  • Property mode set to 100644
File size: 3.9 KB
Line 
1/*
2   Copyright (C) 2004, 2005  Mario Lang <mlang@delysid.org>
3
4   This program is free software; you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 2 of the License, or
7   (at your option) any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program; if not, write to the Free Software
16   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17
18*/
19
20/*
21 
22   This file was taken from the tuneit project, in the file
23   tuneit.c -- Detect fundamental frequency of a sound
24   see http://delysid.org/tuneit.html
25 
26   a fast harmonic comb filter algorithm for pitch tracking
27
28*/
29
30#include "aubio_priv.h"
31#include "sample.h"
32#include "mathutils.h"
33#include "fft.h"
34#include "pitchfcomb.h"
35
36#define MAX_PEAKS 8
37
38typedef struct {
39  smpl_t freq;
40  smpl_t db;
41} aubio_fpeak_t;
42
43struct _aubio_pitchfcomb_t {
44        uint_t fftSize;
45        uint_t stepSize;
46        uint_t rate;
47        fvec_t * winput;
48        fvec_t * win;
49        cvec_t * fftOut;
50        fvec_t * fftLastPhase;
51        aubio_mfft_t * fft;
52        //aubio_pvoc_t * pvoc;
53};
54
55aubio_pitchfcomb_t * new_aubio_pitchfcomb (uint_t bufsize, uint_t hopsize, uint_t samplerate)
56{
57  aubio_pitchfcomb_t * p = AUBIO_NEW(aubio_pitchfcomb_t);
58  p->rate         = samplerate;
59  p->fftSize      = bufsize;
60  p->stepSize     = hopsize; 
61  p->winput       = new_fvec(bufsize,1);
62  p->fftOut       = new_cvec(bufsize,1);
63  p->fftLastPhase = new_fvec(bufsize,1);
64  p->fft = new_aubio_mfft(bufsize, 1);
65  p->win = new_fvec(bufsize,1);
66  aubio_window(p->win->data[0], bufsize, aubio_win_hanning);
67  return p;
68}
69
70/* input must be stepsize long */
71smpl_t aubio_pitchfcomb_detect (aubio_pitchfcomb_t * p, fvec_t * input)
72{
73  uint_t k, l, maxharm = 0;
74  smpl_t freqPerBin = p->rate/(smpl_t)p->fftSize,
75    phaseDifference = TWO_PI*(smpl_t)p->stepSize/(smpl_t)p->fftSize;
76  aubio_fpeak_t peaks[MAX_PEAKS];
77
78  for (k=0; k<MAX_PEAKS; k++) {
79    peaks[k].db = -200.;
80    peaks[k].freq = 0.;
81  }
82
83  for (k=0; k < input->length; k++){
84          p->winput->data[0][k] = p->win->data[0][k] * input->data[0][k];
85  }
86  aubio_mfft_do(p->fft,p->winput,p->fftOut);
87
88  for (k=0; k<=p->fftSize/2; k++) {
89    smpl_t
90      magnitude = 20.*LOG10(2.*p->fftOut->norm[0][k]/(smpl_t)p->fftSize),
91      phase     = p->fftOut->phas[0][k],
92      tmp, freq;
93
94    /* compute phase difference */
95    tmp = phase - p->fftLastPhase->data[0][k];
96    p->fftLastPhase->data[0][k] = phase;
97
98    /* subtract expected phase difference */
99    tmp -= (smpl_t)k*phaseDifference;
100
101    /* map delta phase into +/- Pi interval */
102    tmp = aubio_unwrap2pi(tmp);
103
104    /* get deviation from bin frequency from the +/- Pi interval */
105    tmp = p->fftSize/(smpl_t)p->stepSize*tmp/(TWO_PI);
106
107    /* compute the k-th partials' true frequency */
108    freq = (smpl_t)k*freqPerBin + tmp*freqPerBin;
109
110    if (freq > 0.0 && magnitude > peaks[0].db) { // && magnitude < 0) {
111      memmove(peaks+1, peaks, sizeof(aubio_fpeak_t)*(MAX_PEAKS-1));
112      peaks[0].freq = freq;
113      peaks[0].db = magnitude;
114    }
115  }
116 
117  k = 0;
118  for (l=1; l<MAX_PEAKS && peaks[l].freq > 0.0; l++) {
119    sint_t harmonic;
120    for (harmonic=5; harmonic>1; harmonic--) {
121      if (peaks[0].freq / peaks[l].freq < harmonic+.02 &&
122        peaks[0].freq / peaks[l].freq > harmonic-.02) {
123        if (harmonic > maxharm &&
124          peaks[0].db < peaks[l].db/2) {
125          maxharm = harmonic;
126          k = l;
127        }
128      }
129    }
130  }
131  /* quick hack to clean output a bit */
132  if (peaks[k].freq > 5000.) return 0.;
133  return peaks[k].freq;
134}
135
136void del_aubio_pitchfcomb (aubio_pitchfcomb_t * p)
137{
138  del_cvec(p->fftOut);
139  del_fvec(p->fftLastPhase);
140  del_aubio_mfft(p->fft);
141  AUBIO_FREE(p);
142}
143
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