2 Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org>
3 and Amaury Hazan <ahazan@iua.upf.edu>
5 This file is part of aubio.
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.
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.
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/>.
22 #include "aubio_priv.h"
26 #include "mathutils.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"
36 /** Internal structure for mfcc object */
40 uint_t win_s; /** grain length */
41 uint_t samplerate; /** sample rate (needed?) */
42 uint_t n_filters; /** number of filters */
43 uint_t n_coefs; /** number of coefficients (<= n_filters/2 +1) */
44 aubio_filterbank_t *fb; /** filter bank */
45 fvec_t *in_dct; /** input buffer for dct * [fb->n_filters] */
46 #if defined(HAVE_SLOW_DCT)
47 fmat_t *dct_coeffs; /** DCT transform n_filters * n_coeffs */
56 new_aubio_mfcc (uint_t win_s, uint_t n_filters, uint_t n_coefs,
60 /* allocate space for mfcc object */
61 aubio_mfcc_t *mfcc = AUBIO_NEW (aubio_mfcc_t);
62 #if defined(HAVE_SLOW_DCT)
69 mfcc->samplerate = samplerate;
70 mfcc->n_filters = n_filters;
71 mfcc->n_coefs = n_coefs;
73 /* filterbank allocation */
74 mfcc->fb = new_aubio_filterbank (n_filters, mfcc->win_s);
75 aubio_filterbank_set_mel_coeffs_slaney (mfcc->fb, samplerate);
77 /* allocating buffers */
78 mfcc->in_dct = new_fvec (n_filters);
80 #if defined(HAVE_SLOW_DCT)
81 mfcc->dct_coeffs = new_fmat (n_coefs, n_filters);
83 /* compute DCT transform dct_coeffs[j][i] as
84 cos ( j * (i+.5) * PI / n_filters ) */
85 scaling = 1. / SQRT (n_filters / 2.);
86 for (i = 0; i < n_filters; i++) {
87 for (j = 0; j < n_coefs; j++) {
88 mfcc->dct_coeffs->data[j][i] =
89 scaling * COS (j * (i + 0.5) * PI / n_filters);
91 mfcc->dct_coeffs->data[0][i] *= SQRT (2.) / 2.;
94 mfcc->dct = new_aubio_dct (n_filters);
95 mfcc->output = new_fvec (n_filters);
102 del_aubio_mfcc (aubio_mfcc_t * mf)
105 /* delete filterbank */
106 del_aubio_filterbank (mf->fb);
109 del_fvec (mf->in_dct);
110 #if defined(HAVE_SLOW_DCT)
111 del_fmat (mf->dct_coeffs);
113 del_aubio_dct (mf->dct);
114 del_fvec (mf->output);
117 /* delete mfcc object */
123 aubio_mfcc_do (aubio_mfcc_t * mf, const cvec_t * in, fvec_t * out)
125 /* compute filterbank */
126 aubio_filterbank_do (mf->fb, in, mf->in_dct);
129 fvec_log10 (mf->in_dct);
132 //fvec_pow (mf->in_dct, 3.);
135 #if defined(HAVE_SLOW_DCT)
136 fmat_vecmul(mf->dct_coeffs, mf->in_dct, out);
138 aubio_dct_do(mf->dct, mf->in_dct, mf->output);
139 // copy only first n_coeffs elements
140 // TODO assert mf->output->length == n_coeffs
142 tmp.data = mf->output->data;
143 tmp.length = out->length;
144 fvec_copy(&tmp, out);