source: src/spectral/mfcc.c

Last change on this file was 8affe8c, checked in by Paul Brossier <piem@piem.org>, 6 years ago

[mfcc] get_scale/power return smpl_t

  • Property mode set to 100644
File size: 4.3 KB
Line 
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/** Internal structure for mfcc object */
35
36struct _aubio_mfcc_t
37{
38  uint_t win_s;             /** grain length */
39  uint_t samplerate;        /** sample rate (needed?) */
40  uint_t n_filters;         /** number of filters */
41  uint_t n_coefs;           /** number of coefficients (<= n_filters/2 +1) */
42  aubio_filterbank_t *fb;   /** filter bank */
43  fvec_t *in_dct;           /** input buffer for dct * [fb->n_filters] */
44  aubio_dct_t *dct;         /** dct object */
45  fvec_t *output;           /** dct output */
46  smpl_t scale;
47};
48
49
50aubio_mfcc_t *
51new_aubio_mfcc (uint_t win_s, uint_t n_filters, uint_t n_coefs,
52    uint_t samplerate)
53{
54
55  /* allocate space for mfcc object */
56  aubio_mfcc_t *mfcc = AUBIO_NEW (aubio_mfcc_t);
57
58  if ((sint_t)n_coefs <= 0) {
59    AUBIO_ERR("mfcc: n_coefs should be > 0, got %d\n", n_coefs);
60    goto failure;
61  }
62  if ((sint_t)samplerate <= 0) {
63    AUBIO_ERR("mfcc: samplerate should be > 0, got %d\n", samplerate);
64    goto failure;
65  }
66
67  mfcc->win_s = win_s;
68  mfcc->samplerate = samplerate;
69  mfcc->n_filters = n_filters;
70  mfcc->n_coefs = n_coefs;
71
72  /* filterbank allocation */
73  mfcc->fb = new_aubio_filterbank (n_filters, mfcc->win_s);
74
75  if (!mfcc->fb)
76    goto failure;
77
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  mfcc->dct = new_aubio_dct (n_filters);
88  mfcc->output = new_fvec (n_filters);
89
90  if (!mfcc->in_dct || !mfcc->dct || !mfcc->output)
91    goto failure;
92
93  mfcc->scale = 1.;
94
95  return mfcc;
96
97failure:
98  del_aubio_mfcc(mfcc);
99  return NULL;
100}
101
102void
103del_aubio_mfcc (aubio_mfcc_t * mf)
104{
105  if (mf->fb)
106    del_aubio_filterbank (mf->fb);
107  if (mf->in_dct)
108    del_fvec (mf->in_dct);
109  if (mf->dct)
110    del_aubio_dct (mf->dct);
111  if (mf->output)
112    del_fvec (mf->output);
113  AUBIO_FREE (mf);
114}
115
116
117void
118aubio_mfcc_do (aubio_mfcc_t * mf, const cvec_t * in, fvec_t * out)
119{
120  fvec_t tmp;
121
122  /* compute filterbank */
123  aubio_filterbank_do (mf->fb, in, mf->in_dct);
124
125  /* compute log10 */
126  fvec_log10 (mf->in_dct);
127
128  if (mf->scale != 1) fvec_mul (mf->in_dct, mf->scale);
129
130  /* compute mfccs */
131  aubio_dct_do(mf->dct, mf->in_dct, mf->output);
132  // copy only first n_coeffs elements
133  // TODO assert mf->output->length == n_coeffs
134  tmp.data = mf->output->data;
135  tmp.length = out->length;
136  fvec_copy(&tmp, out);
137
138  return;
139}
140
141uint_t aubio_mfcc_set_power (aubio_mfcc_t *mf, smpl_t power)
142{
143  return aubio_filterbank_set_power(mf->fb, power);
144}
145
146smpl_t aubio_mfcc_get_power (aubio_mfcc_t *mf)
147{
148  return aubio_filterbank_get_power(mf->fb);
149}
150
151uint_t aubio_mfcc_set_scale (aubio_mfcc_t *mf, smpl_t scale)
152{
153  mf->scale = scale;
154  return AUBIO_OK;
155}
156
157smpl_t aubio_mfcc_get_scale (aubio_mfcc_t *mf)
158{
159  return mf->scale;
160}
161
162uint_t aubio_mfcc_set_mel_coeffs (aubio_mfcc_t *mf, smpl_t freq_min,
163    smpl_t freq_max)
164{
165  return aubio_filterbank_set_mel_coeffs(mf->fb, mf->samplerate,
166      freq_min, freq_max);
167}
168
169uint_t aubio_mfcc_set_mel_coeffs_htk (aubio_mfcc_t *mf, smpl_t freq_min,
170    smpl_t freq_max)
171{
172  return aubio_filterbank_set_mel_coeffs_htk(mf->fb, mf->samplerate,
173      freq_min, freq_max);
174}
175
176uint_t aubio_mfcc_set_mel_coeffs_slaney (aubio_mfcc_t *mf)
177{
178  return aubio_filterbank_set_mel_coeffs_slaney (mf->fb, mf->samplerate);
179}
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