1 | /* |
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2 | Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org> |
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3 | and Amaury Hazan <ahazan@iua.upf.edu> |
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4 | |
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5 | This file is part of aubio. |
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6 | |
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7 | aubio is free software: you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation, either version 3 of the License, or |
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10 | (at your option) any later version. |
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11 | |
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12 | aubio is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |
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17 | You should have received a copy of the GNU General Public License |
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18 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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19 | |
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20 | */ |
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21 | |
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22 | #include "aubio_priv.h" |
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23 | #include "fvec.h" |
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24 | #include "fmat.h" |
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25 | #include "cvec.h" |
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26 | #include "mathutils.h" |
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27 | #include "vecutils.h" |
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28 | #include "spectral/fft.h" |
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29 | #include "spectral/filterbank.h" |
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30 | #include "spectral/filterbank_mel.h" |
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31 | #include "spectral/mfcc.h" |
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32 | |
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33 | /** Internal structure for mfcc object */ |
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34 | |
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35 | struct _aubio_mfcc_t |
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36 | { |
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37 | uint_t win_s; /** grain length */ |
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38 | uint_t samplerate; /** sample rate (needed?) */ |
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39 | uint_t n_filters; /** number of filters */ |
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40 | uint_t n_coefs; /** number of coefficients (<= n_filters/2 +1) */ |
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41 | aubio_filterbank_t *fb; /** filter bank */ |
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42 | fvec_t *in_dct; /** input buffer for dct * [fb->n_filters] */ |
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43 | fmat_t *dct_coeffs; /** DCT transform n_filters * n_coeffs */ |
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44 | }; |
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45 | |
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46 | |
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47 | aubio_mfcc_t * |
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48 | new_aubio_mfcc (uint_t win_s, uint_t n_filters, uint_t n_coefs, |
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49 | uint_t samplerate) |
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50 | { |
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51 | |
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52 | /* allocate space for mfcc object */ |
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53 | aubio_mfcc_t *mfcc = AUBIO_NEW (aubio_mfcc_t); |
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54 | smpl_t scaling; |
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55 | |
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56 | uint_t i, j; |
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57 | |
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58 | mfcc->win_s = win_s; |
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59 | mfcc->samplerate = samplerate; |
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60 | mfcc->n_filters = n_filters; |
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61 | mfcc->n_coefs = n_coefs; |
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62 | |
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63 | /* filterbank allocation */ |
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64 | mfcc->fb = new_aubio_filterbank (n_filters, mfcc->win_s); |
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65 | aubio_filterbank_set_mel_coeffs_slaney (mfcc->fb, samplerate); |
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66 | |
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67 | /* allocating buffers */ |
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68 | mfcc->in_dct = new_fvec (n_filters); |
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69 | |
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70 | mfcc->dct_coeffs = new_fmat (n_coefs, n_filters); |
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71 | |
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72 | /* compute DCT transform dct_coeffs[j][i] as |
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73 | cos ( j * (i+.5) * PI / n_filters ) */ |
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74 | scaling = 1. / SQRT (n_filters / 2.); |
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75 | for (i = 0; i < n_filters; i++) { |
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76 | for (j = 0; j < n_coefs; j++) { |
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77 | mfcc->dct_coeffs->data[j][i] = |
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78 | scaling * COS (j * (i + 0.5) * PI / n_filters); |
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79 | } |
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80 | mfcc->dct_coeffs->data[0][i] *= SQRT (2.) / 2.; |
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81 | } |
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82 | |
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83 | return mfcc; |
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84 | } |
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85 | |
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86 | void |
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87 | del_aubio_mfcc (aubio_mfcc_t * mf) |
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88 | { |
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89 | |
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90 | /* delete filterbank */ |
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91 | del_aubio_filterbank (mf->fb); |
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92 | |
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93 | /* delete buffers */ |
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94 | del_fvec (mf->in_dct); |
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95 | del_fmat (mf->dct_coeffs); |
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96 | |
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97 | /* delete mfcc object */ |
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98 | AUBIO_FREE (mf); |
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99 | } |
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100 | |
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101 | |
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102 | void |
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103 | aubio_mfcc_do (aubio_mfcc_t * mf, const cvec_t * in, fvec_t * out) |
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104 | { |
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105 | /* compute filterbank */ |
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106 | aubio_filterbank_do (mf->fb, in, mf->in_dct); |
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107 | |
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108 | /* compute log10 */ |
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109 | fvec_log10 (mf->in_dct); |
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110 | |
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111 | /* raise power */ |
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112 | //fvec_pow (mf->in_dct, 3.); |
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113 | |
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114 | /* compute mfccs */ |
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115 | fmat_vecmul(mf->dct_coeffs, mf->in_dct, out); |
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116 | |
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117 | return; |
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118 | } |
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