[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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[d95ff38] | 23 | #include "fmat.h" |
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[06cae6c] | 24 | #include "fvec.h" |
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| 25 | #include "cvec.h" |
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| 26 | #include "spectral/filterbank.h" |
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| 27 | #include "mathutils.h" |
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| 28 | |
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[3c18f9e] | 29 | uint_t |
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| 30 | aubio_filterbank_set_triangle_bands (aubio_filterbank_t * fb, |
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[59c046d] | 31 | fvec_t * freqs, smpl_t samplerate) |
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[cfd35db] | 32 | { |
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[06cae6c] | 33 | |
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[d95ff38] | 34 | fmat_t *filters = aubio_filterbank_get_coeffs (fb); |
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| 35 | uint_t n_filters = filters->height, win_s = filters->length; |
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[cfd35db] | 36 | |
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[1e37ade] | 37 | uint_t fn; /* filter counter */ |
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| 38 | uint_t bin; /* bin counter */ |
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[cfd35db] | 39 | |
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[1e37ade] | 40 | /* freqs define the bands of triangular overlapping windows. |
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| 41 | throw a warning if filterbank object fb is too short. */ |
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| 42 | if (freqs->length - 2 > n_filters) { |
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| 43 | AUBIO_WRN ("not enough filters, %d allocated but %d requested\n", |
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| 44 | n_filters, freqs->length - 2); |
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[b507607] | 45 | } |
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| 46 | |
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[3c18f9e] | 47 | if (freqs->length - 2 < n_filters) { |
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| 48 | AUBIO_WRN ("too many filters, %d allocated but %d requested\n", |
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| 49 | n_filters, freqs->length - 2); |
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| 50 | } |
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| 51 | |
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[d95ff38] | 52 | if (freqs->data[freqs->length - 1] > samplerate / 2) { |
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[3c18f9e] | 53 | AUBIO_WRN ("Nyquist frequency is %fHz, but highest frequency band ends at \ |
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[d95ff38] | 54 | %fHz\n", samplerate / 2, freqs->data[freqs->length - 1]); |
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[3c18f9e] | 55 | } |
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| 56 | |
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[4e0fbe6] | 57 | /* convenience reference to lower/center/upper frequency for each triangle */ |
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[d95ff38] | 58 | fvec_t *lower_freqs = new_fvec (n_filters); |
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| 59 | fvec_t *upper_freqs = new_fvec (n_filters); |
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| 60 | fvec_t *center_freqs = new_fvec (n_filters); |
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[cfd35db] | 61 | |
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[4e0fbe6] | 62 | /* height of each triangle */ |
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[d95ff38] | 63 | fvec_t *triangle_heights = new_fvec (n_filters); |
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[4e0fbe6] | 64 | |
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| 65 | /* lookup table of each bin frequency in hz */ |
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[d95ff38] | 66 | fvec_t *fft_freqs = new_fvec (win_s); |
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[06cae6c] | 67 | |
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[4e0fbe6] | 68 | /* fill up the lower/center/upper */ |
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[1e37ade] | 69 | for (fn = 0; fn < n_filters; fn++) { |
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[d95ff38] | 70 | lower_freqs->data[fn] = freqs->data[fn]; |
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| 71 | center_freqs->data[fn] = freqs->data[fn + 1]; |
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| 72 | upper_freqs->data[fn] = freqs->data[fn + 2]; |
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[06cae6c] | 73 | } |
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| 74 | |
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[4e0fbe6] | 75 | /* compute triangle heights so that each triangle has unit area */ |
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[1e37ade] | 76 | for (fn = 0; fn < n_filters; fn++) { |
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[d95ff38] | 77 | triangle_heights->data[fn] = |
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| 78 | 2. / (upper_freqs->data[fn] - lower_freqs->data[fn]); |
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[06cae6c] | 79 | } |
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[cfd35db] | 80 | |
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[4e0fbe6] | 81 | /* fill fft_freqs lookup table, which assigns the frequency in hz to each bin */ |
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| 82 | for (bin = 0; bin < win_s; bin++) { |
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[d95ff38] | 83 | fft_freqs->data[bin] = |
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[3c18f9e] | 84 | aubio_bintofreq (bin, samplerate, (win_s - 1) * 2); |
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[06cae6c] | 85 | } |
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| 86 | |
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[4e0fbe6] | 87 | /* zeroing of all filters */ |
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[d95ff38] | 88 | fmat_zeros (filters); |
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[b507607] | 89 | |
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[d95ff38] | 90 | if (fft_freqs->data[1] >= lower_freqs->data[0]) { |
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[3c18f9e] | 91 | /* - 1 to make sure we don't miss the smallest power of two */ |
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| 92 | uint_t min_win_s = |
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[d95ff38] | 93 | (uint_t) FLOOR (samplerate / lower_freqs->data[0]) - 1; |
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[3c18f9e] | 94 | AUBIO_WRN ("Lowest frequency bin (%.2fHz) is higher than lowest frequency \ |
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| 95 | band (%.2f-%.2fHz). Consider increasing the window size from %d to %d.\n", |
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[d95ff38] | 96 | fft_freqs->data[1], lower_freqs->data[0], |
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| 97 | upper_freqs->data[0], (win_s - 1) * 2, |
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[3c18f9e] | 98 | aubio_next_power_of_two (min_win_s)); |
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| 99 | } |
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| 100 | |
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[b507607] | 101 | /* building each filter table */ |
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[4e0fbe6] | 102 | for (fn = 0; fn < n_filters; fn++) { |
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[cfd35db] | 103 | |
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[b507607] | 104 | /* skip first elements */ |
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[4e0fbe6] | 105 | for (bin = 0; bin < win_s - 1; bin++) { |
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[d95ff38] | 106 | if (fft_freqs->data[bin] <= lower_freqs->data[fn] && |
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| 107 | fft_freqs->data[bin + 1] > lower_freqs->data[fn]) { |
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[3c18f9e] | 108 | bin++; |
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[06cae6c] | 109 | break; |
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| 110 | } |
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| 111 | } |
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[cfd35db] | 112 | |
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[b507607] | 113 | /* compute positive slope step size */ |
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| 114 | smpl_t riseInc = |
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[d95ff38] | 115 | triangle_heights->data[fn] / |
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| 116 | (center_freqs->data[fn] - lower_freqs->data[fn]); |
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[b507607] | 117 | |
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| 118 | /* compute coefficients in positive slope */ |
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[4e0fbe6] | 119 | for (; bin < win_s - 1; bin++) { |
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| 120 | filters->data[fn][bin] = |
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[d95ff38] | 121 | (fft_freqs->data[bin] - lower_freqs->data[fn]) * riseInc; |
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[4e0fbe6] | 122 | |
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[d95ff38] | 123 | if (fft_freqs->data[bin + 1] >= center_freqs->data[fn]) { |
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[3c18f9e] | 124 | bin++; |
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[06cae6c] | 125 | break; |
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[3c18f9e] | 126 | } |
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[06cae6c] | 127 | } |
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[b507607] | 128 | |
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| 129 | /* compute negative slope step size */ |
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| 130 | smpl_t downInc = |
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[d95ff38] | 131 | triangle_heights->data[fn] / |
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| 132 | (upper_freqs->data[fn] - center_freqs->data[fn]); |
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[cfd35db] | 133 | |
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[b507607] | 134 | /* compute coefficents in negative slope */ |
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[4e0fbe6] | 135 | for (; bin < win_s - 1; bin++) { |
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| 136 | filters->data[fn][bin] += |
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[d95ff38] | 137 | (upper_freqs->data[fn] - fft_freqs->data[bin]) * downInc; |
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[cfd35db] | 138 | |
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[3c18f9e] | 139 | if (filters->data[fn][bin] < 0.) { |
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| 140 | filters->data[fn][bin] = 0.; |
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| 141 | } |
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| 142 | |
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[d95ff38] | 143 | if (fft_freqs->data[bin + 1] >= upper_freqs->data[fn]) |
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[06cae6c] | 144 | break; |
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| 145 | } |
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[b507607] | 146 | /* nothing else to do */ |
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[06cae6c] | 147 | |
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| 148 | } |
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| 149 | |
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[cfd35db] | 150 | /* destroy temporarly allocated vectors */ |
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| 151 | del_fvec (lower_freqs); |
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| 152 | del_fvec (upper_freqs); |
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| 153 | del_fvec (center_freqs); |
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[06cae6c] | 154 | |
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[cfd35db] | 155 | del_fvec (triangle_heights); |
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| 156 | del_fvec (fft_freqs); |
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[06cae6c] | 157 | |
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[3c18f9e] | 158 | return 0; |
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[cfd35db] | 159 | } |
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[1e37ade] | 160 | |
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[3c18f9e] | 161 | uint_t |
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[1e37ade] | 162 | aubio_filterbank_set_mel_coeffs_slaney (aubio_filterbank_t * fb, |
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| 163 | smpl_t samplerate) |
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| 164 | { |
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[3c18f9e] | 165 | uint_t retval; |
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| 166 | |
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[1e37ade] | 167 | /* Malcolm Slaney parameters */ |
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| 168 | smpl_t lowestFrequency = 133.3333; |
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| 169 | smpl_t linearSpacing = 66.66666666; |
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| 170 | smpl_t logSpacing = 1.0711703; |
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| 171 | |
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| 172 | uint_t linearFilters = 13; |
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| 173 | uint_t logFilters = 27; |
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| 174 | uint_t n_filters = linearFilters + logFilters; |
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| 175 | |
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| 176 | uint_t fn; /* filter counter */ |
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| 177 | |
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| 178 | /* buffers to compute filter frequencies */ |
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[d95ff38] | 179 | fvec_t *freqs = new_fvec (n_filters + 2); |
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[1e37ade] | 180 | |
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| 181 | /* first step: fill all the linear filter frequencies */ |
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| 182 | for (fn = 0; fn < linearFilters; fn++) { |
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[d95ff38] | 183 | freqs->data[fn] = lowestFrequency + fn * linearSpacing; |
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[1e37ade] | 184 | } |
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[d95ff38] | 185 | smpl_t lastlinearCF = freqs->data[fn - 1]; |
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[1e37ade] | 186 | |
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| 187 | /* second step: fill all the log filter frequencies */ |
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| 188 | for (fn = 0; fn < logFilters + 2; fn++) { |
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[d95ff38] | 189 | freqs->data[fn + linearFilters] = |
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[1e37ade] | 190 | lastlinearCF * (POW (logSpacing, fn + 1)); |
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| 191 | } |
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| 192 | |
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| 193 | /* now compute the actual coefficients */ |
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[59c046d] | 194 | retval = aubio_filterbank_set_triangle_bands (fb, freqs, samplerate); |
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[1e37ade] | 195 | |
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| 196 | /* destroy vector used to store frequency limits */ |
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| 197 | del_fvec (freqs); |
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| 198 | |
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[3c18f9e] | 199 | return retval; |
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[1e37ade] | 200 | } |
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