source: src/pitchfcomb.c @ 8d84c0b

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretchpitchshiftsamplertimestretchyinfft+
Last change on this file since 8d84c0b was 8d84c0b, checked in by Paul Brossier <piem@altern.org>, 16 years ago

added raw output cleaning

  • Property mode set to 100644
File size: 3.6 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 "phasevoc.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 rate;
46        cvec_t * fftOut;
47        fvec_t * fftLastPhase;
48        aubio_pvoc_t * pvoc;
49};
50
51aubio_pitchfcomb_t * new_aubio_pitchfcomb (uint_t size, uint_t samplerate)
52{
53  aubio_pitchfcomb_t * p = AUBIO_NEW(aubio_pitchfcomb_t);
54  uint_t overlap_rate = 4;
55  p->rate         = samplerate;
56  p->fftSize      = size;
57  p->fftOut       = new_cvec(size,1);
58  p->fftLastPhase = new_fvec(size,1);
59  p->pvoc = new_aubio_pvoc(size, size/overlap_rate, 1);
60  return p;
61}
62
63/* input must be stepsize long */
64smpl_t aubio_pitchfcomb_detect (aubio_pitchfcomb_t * p, fvec_t * input)
65{
66  uint_t k, l, maxharm = 0, stepSize = input->length;
67  smpl_t freqPerBin = p->rate/(smpl_t)p->fftSize,
68    phaseDifference = TWO_PI*(smpl_t)stepSize/(smpl_t)p->fftSize;
69  aubio_fpeak_t peaks[MAX_PEAKS];
70
71  for (k=0; k<MAX_PEAKS; k++) {
72    peaks[k].db = -200.;
73    peaks[k].freq = 0.;
74  }
75
76  aubio_pvoc_do (p->pvoc, input, p->fftOut);
77
78  for (k=0; k<=p->fftSize; k++) {
79    //long qpd;
80    smpl_t
81      magnitude = 20.*LOG10(2.*p->fftOut->norm[0][k]/(smpl_t)p->fftSize),
82      phase     = p->fftOut->phas[0][k],
83      tmp, freq;
84
85    /* compute phase difference */
86    tmp = phase - p->fftLastPhase->data[0][k];
87    p->fftLastPhase->data[0][k] = phase;
88
89    /* subtract expected phase difference */
90    tmp -= (smpl_t)k*phaseDifference;
91
92    /* map delta phase into +/- Pi interval */
93    tmp = unwrap2pi(tmp);
94
95    /* get deviation from bin frequency from the +/- Pi interval */
96    tmp = p->fftSize/input->length*tmp/(TWO_PI);
97
98    /* compute the k-th partials' true frequency */
99    freq = (smpl_t)k*freqPerBin + tmp*freqPerBin;
100
101    if (freq > 0.0 && magnitude > peaks[0].db && magnitude < 0) {
102      memmove(peaks+1, peaks, sizeof(aubio_fpeak_t)*(MAX_PEAKS-1));
103      peaks[0].freq = freq;
104      peaks[0].db = magnitude;
105    }
106  }
107 
108  k = 0;
109  for (l=1; l<MAX_PEAKS && peaks[l].freq > 0.0; l++) {
110    sint_t harmonic;
111    for (harmonic=5; harmonic>1; harmonic--) {
112      if (peaks[0].freq / peaks[l].freq < harmonic+.02 &&
113        peaks[0].freq / peaks[l].freq > harmonic-.02) {
114        if (harmonic > maxharm &&
115          peaks[0].db < peaks[l].db/2) {
116          maxharm = harmonic;
117          k = l;
118        }
119      }
120    }
121  }
122  /* quick hack to clean output a bit */
123  if (peaks[k].freq > 10000) return 0.;
124  return peaks[k].freq;
125}
126
127void del_aubio_pitchfcomb (aubio_pitchfcomb_t * p)
128{
129  del_cvec(p->fftOut);
130  del_fvec(p->fftLastPhase);
131  del_aubio_pvoc(p->pvoc);
132  AUBIO_FREE(p);
133}
134
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