1 | /* |
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2 | Copyright (C) 2018 Paul Brossier <piem@aubio.org> |
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3 | |
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4 | This file is part of aubio. |
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5 | |
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6 | aubio is free software: you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation, either version 3 of the License, or |
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9 | (at your option) any later version. |
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10 | |
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11 | aubio is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License |
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17 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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18 | |
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19 | */ |
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20 | |
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21 | /** \file |
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22 | |
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23 | Constant-Q Transform |
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24 | |
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25 | TODO add long description |
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26 | |
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27 | \example spectral/test-constantq.c |
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28 | |
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29 | */ |
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30 | |
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31 | #include "aubio_priv.h" |
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32 | #include "fvec.h" |
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33 | #include "cvec.h" |
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34 | #include "fmat.h" |
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35 | #include "spectral/constantq.h" |
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36 | |
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37 | struct _aubio_constantq_t { |
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38 | uint_t size; |
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39 | uint_t samplerate; |
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40 | uint_t bins_per_octave; |
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41 | fmat_t *coeffs; |
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42 | smpl_t high_freq; |
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43 | smpl_t low_freq; |
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44 | }; |
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45 | |
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46 | uint_t aubio_constantq_reset_filters (aubio_constantq_t *s); |
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47 | |
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48 | aubio_constantq_t * new_aubio_constantq(uint_t size, uint_t samplerate, |
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49 | uint_t bins_per_octave) { |
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50 | aubio_constantq_t * s = AUBIO_NEW (aubio_constantq_t); |
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51 | if ((sint_t) size <= 0) { |
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52 | AUBIO_ERROR("constantq: failed creating with size %d, should be > 0\n", |
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53 | size); |
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54 | goto beach; |
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55 | } |
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56 | if ((sint_t) bins_per_octave <= 0) { |
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57 | AUBIO_ERROR("constantq: failed creating with bins_per_octave %d" |
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58 | ", should be > 0\n", bins_per_octave); |
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59 | goto beach; |
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60 | } |
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61 | |
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62 | s->size = size / 2 + 1; |
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63 | s->samplerate = samplerate; |
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64 | s->bins_per_octave = bins_per_octave; |
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65 | s->low_freq = aubio_miditofreq(19.0); |
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66 | s->high_freq = aubio_miditofreq(MIN(140.0, 139.0 + 12.0/s->bins_per_octave)); |
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67 | if (aubio_constantq_reset_filters (s) != AUBIO_OK) goto beach; |
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68 | //AUBIO_WRN ("constantq: %d size, %d Hz, %d bins\n", s->size, s->samplerate, |
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69 | // s->bins_per_octave); |
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70 | return s; |
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71 | beach: |
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72 | AUBIO_FREE(s); |
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73 | return NULL; |
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74 | } |
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75 | |
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76 | uint_t aubio_constantq_reset_filters (aubio_constantq_t *s) |
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77 | { |
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78 | // compute transform coefficients |
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79 | uint_t i, j; |
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80 | smpl_t ratio = POW(2.0, 1.0 / s->bins_per_octave); |
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81 | uint_t nbins = (uint_t) FLOOR (LOG (s->high_freq / s->low_freq) / LOG (ratio)); |
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82 | if (nbins <= 0) { |
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83 | AUBIO_ERROR ("constantq: can not be created with 0 bins, low_freq %.2f, " |
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84 | "high_freq %.2f, bins_per_octave %d\n", s->low_freq, s->high_freq, |
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85 | s->bins_per_octave); |
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86 | return AUBIO_FAIL; |
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87 | } |
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88 | if (s->coeffs) del_fmat(s->coeffs); |
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89 | s->coeffs = new_fmat (nbins, s->size); |
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90 | |
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91 | smpl_t freq_step = s->samplerate * 0.5 / (s->size - 1.); |
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92 | smpl_t min_bw = (smpl_t) s->samplerate / (smpl_t) s->size; |
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93 | |
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94 | for (i = 0; i < nbins; i++) { |
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95 | smpl_t band_freq = s->low_freq * POW (ratio, i); |
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96 | smpl_t band_bw = MAX (band_freq * (ratio - 1.), min_bw); |
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97 | for (j = 0; j < s->size; j++) { |
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98 | smpl_t fftfreq = j * freq_step; |
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99 | smpl_t val = (band_freq - fftfreq) / band_bw; |
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100 | s->coeffs->data[i][j] = EXP (- 0.5 * SQR(val)); |
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101 | } |
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102 | } |
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103 | |
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104 | return AUBIO_OK; |
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105 | } |
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106 | |
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107 | void del_aubio_constantq(aubio_constantq_t *s) { |
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108 | del_fmat(s->coeffs); |
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109 | AUBIO_FREE(s); |
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110 | } |
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111 | |
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112 | void aubio_constantq_do(aubio_constantq_t *s, const cvec_t *input, |
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113 | fvec_t *cqt_output) { |
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114 | fvec_t input_norm; |
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115 | input_norm.length = input->length; |
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116 | input_norm.data = input->norm; |
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117 | fmat_vecmul (s->coeffs, &input_norm, cqt_output); |
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118 | } |
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119 | |
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120 | uint_t aubio_constantq_get_numbins (aubio_constantq_t *s) { |
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121 | if (!s || !s->coeffs) return 0; |
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122 | return s->coeffs->height; |
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123 | } |
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