[06cae6c] | 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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[1c2e186] | 5 | This file is part of aubio. |
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[06cae6c] | 6 | |
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[1c2e186] | 7 | aubio is free software: you can redistribute it and/or modify |
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[06cae6c] | 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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[1c2e186] | 12 | aubio is distributed in the hope that it will be useful, |
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[06cae6c] | 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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[1c2e186] | 18 | along with aubio. If not, see <http://www.gnu.org/licenses/>. |
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[06cae6c] | 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 "cvec.h" |
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| 25 | #include "spectral/filterbank.h" |
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| 26 | #include "mathutils.h" |
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| 27 | |
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[cfd35db] | 28 | void |
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[1e37ade] | 29 | aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, fvec_t * freqs, |
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| 30 | smpl_t samplerate) |
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[cfd35db] | 31 | { |
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[06cae6c] | 32 | |
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[cfd35db] | 33 | fvec_t *filters = aubio_filterbank_get_coeffs (fb); |
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[06cae6c] | 34 | uint_t n_filters = filters->channels, win_s = filters->length; |
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[cfd35db] | 35 | |
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[1e37ade] | 36 | uint_t fn; /* filter counter */ |
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| 37 | uint_t bin; /* bin counter */ |
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[cfd35db] | 38 | |
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[1e37ade] | 39 | /* freqs define the bands of triangular overlapping windows. |
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| 40 | throw a warning if filterbank object fb is too short. */ |
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| 41 | if (freqs->length - 2 > n_filters) { |
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| 42 | AUBIO_WRN ("not enough filters, %d allocated but %d requested\n", |
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| 43 | n_filters, freqs->length - 2); |
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[b507607] | 44 | } |
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| 45 | |
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[4e0fbe6] | 46 | /* convenience reference to lower/center/upper frequency for each triangle */ |
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[1e37ade] | 47 | fvec_t *lower_freqs = new_fvec (n_filters, 1); |
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| 48 | fvec_t *upper_freqs = new_fvec (n_filters, 1); |
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| 49 | fvec_t *center_freqs = new_fvec (n_filters, 1); |
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[cfd35db] | 50 | |
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[4e0fbe6] | 51 | /* height of each triangle */ |
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[1e37ade] | 52 | fvec_t *triangle_heights = new_fvec (n_filters, 1); |
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[4e0fbe6] | 53 | |
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| 54 | /* lookup table of each bin frequency in hz */ |
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[cfd35db] | 55 | fvec_t *fft_freqs = new_fvec (win_s, 1); |
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[06cae6c] | 56 | |
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[4e0fbe6] | 57 | /* fill up the lower/center/upper */ |
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[1e37ade] | 58 | for (fn = 0; fn < n_filters; fn++) { |
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[4e0fbe6] | 59 | lower_freqs->data[0][fn] = freqs->data[0][fn]; |
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| 60 | center_freqs->data[0][fn] = freqs->data[0][fn + 1]; |
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| 61 | upper_freqs->data[0][fn] = freqs->data[0][fn + 2]; |
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[06cae6c] | 62 | } |
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| 63 | |
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[4e0fbe6] | 64 | /* compute triangle heights so that each triangle has unit area */ |
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[1e37ade] | 65 | for (fn = 0; fn < n_filters; fn++) { |
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[4e0fbe6] | 66 | triangle_heights->data[0][fn] = |
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| 67 | 2. / (upper_freqs->data[0][fn] - lower_freqs->data[0][fn]); |
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[06cae6c] | 68 | } |
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[cfd35db] | 69 | |
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[4e0fbe6] | 70 | /* fill fft_freqs lookup table, which assigns the frequency in hz to each bin */ |
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| 71 | for (bin = 0; bin < win_s; bin++) { |
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[2062e48] | 72 | fft_freqs->data[0][bin] = aubio_bintofreq (bin, samplerate, (win_s - 1) * 2); |
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[06cae6c] | 73 | } |
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| 74 | |
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[4e0fbe6] | 75 | /* zeroing of all filters */ |
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| 76 | fvec_zeros (filters); |
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[b507607] | 77 | |
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| 78 | /* building each filter table */ |
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[4e0fbe6] | 79 | for (fn = 0; fn < n_filters; fn++) { |
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[cfd35db] | 80 | |
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[b507607] | 81 | /* skip first elements */ |
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[4e0fbe6] | 82 | for (bin = 0; bin < win_s - 1; bin++) { |
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| 83 | if (fft_freqs->data[0][bin] <= lower_freqs->data[0][fn] && |
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| 84 | fft_freqs->data[0][bin + 1] > lower_freqs->data[0][fn]) { |
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[06cae6c] | 85 | break; |
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| 86 | } |
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| 87 | } |
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[4e0fbe6] | 88 | bin++; |
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[cfd35db] | 89 | |
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[b507607] | 90 | /* compute positive slope step size */ |
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| 91 | smpl_t riseInc = |
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[4e0fbe6] | 92 | triangle_heights->data[0][fn] / |
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| 93 | (center_freqs->data[0][fn] - lower_freqs->data[0][fn]); |
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[b507607] | 94 | |
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| 95 | /* compute coefficients in positive slope */ |
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[4e0fbe6] | 96 | for (; bin < win_s - 1; bin++) { |
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| 97 | filters->data[fn][bin] = |
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| 98 | (fft_freqs->data[0][bin] - lower_freqs->data[0][fn]) * riseInc; |
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| 99 | |
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| 100 | if (fft_freqs->data[0][bin + 1] > center_freqs->data[0][fn]) |
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[06cae6c] | 101 | break; |
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| 102 | } |
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[4e0fbe6] | 103 | bin++; |
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[b507607] | 104 | |
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| 105 | /* compute negative slope step size */ |
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| 106 | smpl_t downInc = |
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[4e0fbe6] | 107 | triangle_heights->data[0][fn] / |
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| 108 | (upper_freqs->data[0][fn] - center_freqs->data[0][fn]); |
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[cfd35db] | 109 | |
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[b507607] | 110 | /* compute coefficents in negative slope */ |
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[4e0fbe6] | 111 | for (; bin < win_s - 1; bin++) { |
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| 112 | filters->data[fn][bin] += |
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| 113 | (upper_freqs->data[0][fn] - fft_freqs->data[0][bin]) * downInc; |
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[cfd35db] | 114 | |
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[4e0fbe6] | 115 | if (fft_freqs->data[0][bin + 1] > upper_freqs->data[0][fn]) |
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[06cae6c] | 116 | break; |
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| 117 | } |
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[b507607] | 118 | /* nothing else to do */ |
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[06cae6c] | 119 | |
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| 120 | } |
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| 121 | |
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[cfd35db] | 122 | /* destroy temporarly allocated vectors */ |
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| 123 | del_fvec (lower_freqs); |
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| 124 | del_fvec (upper_freqs); |
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| 125 | del_fvec (center_freqs); |
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[06cae6c] | 126 | |
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[cfd35db] | 127 | del_fvec (triangle_heights); |
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| 128 | del_fvec (fft_freqs); |
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[06cae6c] | 129 | |
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[cfd35db] | 130 | } |
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[1e37ade] | 131 | |
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| 132 | void |
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| 133 | aubio_filterbank_set_mel_coeffs_slaney (aubio_filterbank_t * fb, |
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| 134 | smpl_t samplerate) |
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| 135 | { |
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| 136 | /* Malcolm Slaney parameters */ |
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| 137 | smpl_t lowestFrequency = 133.3333; |
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| 138 | smpl_t linearSpacing = 66.66666666; |
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| 139 | smpl_t logSpacing = 1.0711703; |
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| 140 | |
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| 141 | uint_t linearFilters = 13; |
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| 142 | uint_t logFilters = 27; |
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| 143 | uint_t n_filters = linearFilters + logFilters; |
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| 144 | |
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| 145 | uint_t fn; /* filter counter */ |
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| 146 | |
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| 147 | /* buffers to compute filter frequencies */ |
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| 148 | fvec_t *freqs = new_fvec (n_filters + 2, 1); |
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| 149 | |
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| 150 | /* first step: fill all the linear filter frequencies */ |
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| 151 | for (fn = 0; fn < linearFilters; fn++) { |
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| 152 | freqs->data[0][fn] = lowestFrequency + fn * linearSpacing; |
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| 153 | } |
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| 154 | smpl_t lastlinearCF = freqs->data[0][fn - 1]; |
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| 155 | |
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| 156 | /* second step: fill all the log filter frequencies */ |
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| 157 | for (fn = 0; fn < logFilters + 2; fn++) { |
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| 158 | freqs->data[0][fn + linearFilters] = |
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| 159 | lastlinearCF * (POW (logSpacing, fn + 1)); |
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| 160 | } |
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| 161 | |
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| 162 | /* now compute the actual coefficients */ |
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| 163 | aubio_filterbank_set_mel_coeffs (fb, freqs, samplerate); |
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| 164 | |
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| 165 | /* destroy vector used to store frequency limits */ |
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| 166 | del_fvec (freqs); |
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| 167 | |
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| 168 | } |
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