source: src/spectral/mfcc.c @ 1c1dae7

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretch
Last change on this file since 1c1dae7 was 1c1dae7, checked in by Paul Brossier <piem@piem.org>, 12 months ago

[mfcc] default to full range when not using 40 filters

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File size: 4.7 KB
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1/*
2  Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org>
3                      and Amaury Hazan <ahazan@iua.upf.edu>
4
5  This file is part of aubio.
6
7  aubio is free software: you can redistribute it and/or modify
8  it under the terms of the GNU General Public License as published by
9  the Free Software Foundation, either version 3 of the License, or
10  (at your option) any later version.
11
12  aubio is distributed in the hope that it will be useful,
13  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  GNU General Public License for more details.
16
17  You should have received a copy of the GNU General Public License
18  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
19
20*/
21
22#include "aubio_priv.h"
23#include "fvec.h"
24#include "fmat.h"
25#include "cvec.h"
26#include "mathutils.h"
27#include "vecutils.h"
28#include "spectral/fft.h"
29#include "spectral/filterbank.h"
30#include "spectral/filterbank_mel.h"
31#include "spectral/dct.h"
32#include "spectral/mfcc.h"
33
34#ifdef HAVE_NOOPT
35#define HAVE_SLOW_DCT 1
36#endif
37
38/** Internal structure for mfcc object */
39
40struct _aubio_mfcc_t
41{
42  uint_t win_s;             /** grain length */
43  uint_t samplerate;        /** sample rate (needed?) */
44  uint_t n_filters;         /** number of filters */
45  uint_t n_coefs;           /** number of coefficients (<= n_filters/2 +1) */
46  aubio_filterbank_t *fb;   /** filter bank */
47  fvec_t *in_dct;           /** input buffer for dct * [fb->n_filters] */
48#if defined(HAVE_SLOW_DCT)
49  fmat_t *dct_coeffs;       /** DCT transform n_filters * n_coeffs */
50#else
51  aubio_dct_t *dct;
52  fvec_t *output;
53#endif
54  smpl_t scale;
55};
56
57
58aubio_mfcc_t *
59new_aubio_mfcc (uint_t win_s, uint_t n_filters, uint_t n_coefs,
60    uint_t samplerate)
61{
62
63  /* allocate space for mfcc object */
64  aubio_mfcc_t *mfcc = AUBIO_NEW (aubio_mfcc_t);
65#if defined(HAVE_SLOW_DCT)
66  smpl_t scaling;
67
68  uint_t i, j;
69#endif
70
71  mfcc->win_s = win_s;
72  mfcc->samplerate = samplerate;
73  mfcc->n_filters = n_filters;
74  mfcc->n_coefs = n_coefs;
75
76  /* filterbank allocation */
77  mfcc->fb = new_aubio_filterbank (n_filters, mfcc->win_s);
78  if (n_filters == 40)
79    aubio_filterbank_set_mel_coeffs_slaney (mfcc->fb, samplerate);
80  else
81    aubio_filterbank_set_mel_coeffs(mfcc->fb, samplerate,
82        0, samplerate/2.);
83
84  /* allocating buffers */
85  mfcc->in_dct = new_fvec (n_filters);
86
87#if defined(HAVE_SLOW_DCT)
88  mfcc->dct_coeffs = new_fmat (n_coefs, n_filters);
89
90  /* compute DCT transform dct_coeffs[j][i] as
91     cos ( j * (i+.5) * PI / n_filters ) */
92  scaling = 1. / SQRT (n_filters / 2.);
93  for (i = 0; i < n_filters; i++) {
94    for (j = 0; j < n_coefs; j++) {
95      mfcc->dct_coeffs->data[j][i] =
96          scaling * COS (j * (i + 0.5) * PI / n_filters);
97    }
98    mfcc->dct_coeffs->data[0][i] *= SQRT (2.) / 2.;
99  }
100#else
101  mfcc->dct = new_aubio_dct (n_filters);
102  mfcc->output = new_fvec (n_filters);
103#endif
104
105  mfcc->scale = 1.;
106
107  return mfcc;
108}
109
110void
111del_aubio_mfcc (aubio_mfcc_t * mf)
112{
113
114  /* delete filterbank */
115  del_aubio_filterbank (mf->fb);
116
117  /* delete buffers */
118  del_fvec (mf->in_dct);
119#if defined(HAVE_SLOW_DCT)
120  del_fmat (mf->dct_coeffs);
121#else
122  del_aubio_dct (mf->dct);
123  del_fvec (mf->output);
124#endif
125
126  /* delete mfcc object */
127  AUBIO_FREE (mf);
128}
129
130
131void
132aubio_mfcc_do (aubio_mfcc_t * mf, const cvec_t * in, fvec_t * out)
133{
134#ifndef HAVE_SLOW_DCT
135  fvec_t tmp;
136#endif
137
138  /* compute filterbank */
139  aubio_filterbank_do (mf->fb, in, mf->in_dct);
140
141  /* compute log10 */
142  fvec_log10 (mf->in_dct);
143
144  if (mf->scale != 1) fvec_mul (mf->in_dct, mf->scale);
145
146  /* compute mfccs */
147#if defined(HAVE_SLOW_DCT)
148  fmat_vecmul(mf->dct_coeffs, mf->in_dct, out);
149#else
150  aubio_dct_do(mf->dct, mf->in_dct, mf->output);
151  // copy only first n_coeffs elements
152  // TODO assert mf->output->length == n_coeffs
153  tmp.data = mf->output->data;
154  tmp.length = out->length;
155  fvec_copy(&tmp, out);
156#endif
157
158  return;
159}
160
161uint_t aubio_mfcc_set_power (aubio_mfcc_t *mf, smpl_t power)
162{
163  return aubio_filterbank_set_power(mf->fb, power);
164}
165
166uint_t aubio_mfcc_get_power (aubio_mfcc_t *mf)
167{
168  return aubio_filterbank_get_power(mf->fb);
169}
170
171uint_t aubio_mfcc_set_scale (aubio_mfcc_t *mf, smpl_t scale)
172{
173  mf->scale = scale;
174  return AUBIO_OK;
175}
176
177uint_t aubio_mfcc_get_scale (aubio_mfcc_t *mf)
178{
179  return mf->scale;
180}
181
182uint_t aubio_mfcc_set_mel_coeffs (aubio_mfcc_t *mf, smpl_t freq_min,
183    smpl_t freq_max)
184{
185  return aubio_filterbank_set_mel_coeffs(mf->fb, mf->samplerate,
186      freq_min, freq_max);
187}
188
189uint_t aubio_mfcc_set_mel_coeffs_htk (aubio_mfcc_t *mf, smpl_t freq_min,
190    smpl_t freq_max)
191{
192  return aubio_filterbank_set_mel_coeffs_htk(mf->fb, mf->samplerate,
193      freq_min, freq_max);
194}
195
196uint_t aubio_mfcc_set_mel_coeffs_slaney (aubio_mfcc_t *mf)
197{
198  return aubio_filterbank_set_mel_coeffs_slaney (mf->fb, mf->samplerate);
199}
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