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"
25 #include "spectral/filterbank.h"
26 #include "mathutils.h"
29 aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, uint_t samplerate,
30 smpl_t freq_min, smpl_t freq_max)
33 fvec_t *filters = aubio_filterbank_get_coeffs (fb);
34 uint_t n_filters = filters->channels, win_s = filters->length;
37 smpl_t lowestFrequency = 133.3333;
38 smpl_t linearSpacing = 66.66666666;
39 smpl_t logSpacing = 1.0711703;
41 uint_t linearFilters = 13;
42 uint_t logFilters = 27;
43 uint_t allFilters = linearFilters + logFilters;
45 //buffers for computing filter frequencies
46 fvec_t *freqs = new_fvec (allFilters + 2, 1);
48 fvec_t *lower_freqs = new_fvec (allFilters, 1);
49 fvec_t *upper_freqs = new_fvec (allFilters, 1);
50 fvec_t *center_freqs = new_fvec (allFilters, 1);
52 fvec_t *triangle_heights = new_fvec (allFilters, 1);
53 //lookup table of each bin frequency in hz
54 fvec_t *fft_freqs = new_fvec (win_s, 1);
56 uint_t filter_cnt, bin_cnt;
58 //first step: filling all the linear filter frequencies
59 for (filter_cnt = 0; filter_cnt < linearFilters; filter_cnt++) {
60 freqs->data[0][filter_cnt] = lowestFrequency + filter_cnt * linearSpacing;
62 smpl_t lastlinearCF = freqs->data[0][filter_cnt - 1];
64 //second step: filling all the log filter frequencies
65 for (filter_cnt = 0; filter_cnt < logFilters + 2; filter_cnt++) {
66 freqs->data[0][filter_cnt + linearFilters] =
67 lastlinearCF * (pow (logSpacing, filter_cnt + 1));
70 //Option 1. copying interesting values to lower_freqs, center_freqs and upper freqs arrays
71 //TODO: would be nicer to have a reference to freqs->data, anyway we do not care in this init step
73 for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) {
74 lower_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt];
75 center_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt + 1];
76 upper_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt + 2];
79 //computing triangle heights so that each triangle has unit area
80 for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) {
81 triangle_heights->data[0][filter_cnt] =
82 2. / (upper_freqs->data[0][filter_cnt]
83 - lower_freqs->data[0][filter_cnt]);
86 //AUBIO_DBG("filter tables frequencies\n");
87 //for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++)
88 // AUBIO_DBG("filter n. %d %f %f %f %f\n",
89 // filter_cnt, lower_freqs->data[0][filter_cnt],
90 // center_freqs->data[0][filter_cnt], upper_freqs->data[0][filter_cnt],
91 // triangle_heights->data[0][filter_cnt]);
93 //filling the fft_freqs lookup table, which assigns the frequency in hz to each bin
94 for (bin_cnt = 0; bin_cnt < win_s; bin_cnt++) {
95 fft_freqs->data[0][bin_cnt] = aubio_bintofreq (bin_cnt, samplerate, win_s);
98 //building each filter table
99 for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) {
101 //TODO:check special case : lower freq =0
102 //calculating rise increment in mag/Hz
104 triangle_heights->data[0][filter_cnt] /
105 (center_freqs->data[0][filter_cnt] - lower_freqs->data[0][filter_cnt]);
107 //zeroing begining of filter
108 for (bin_cnt = 0; bin_cnt < win_s - 1; bin_cnt++) {
109 filters->data[filter_cnt][bin_cnt] = 0.0;
110 if (fft_freqs->data[0][bin_cnt] <= lower_freqs->data[0][filter_cnt] &&
111 fft_freqs->data[0][bin_cnt + 1] > lower_freqs->data[0][filter_cnt]) {
118 for (; bin_cnt < win_s - 1; bin_cnt++) {
119 filters->data[filter_cnt][bin_cnt] =
120 (fft_freqs->data[0][bin_cnt] -
121 lower_freqs->data[0][filter_cnt]) * riseInc;
122 //if(fft_freqs->data[0][bin_cnt]<= center_freqs->data[0][filter_cnt] && fft_freqs->data[0][bin_cnt+1]> center_freqs->data[0][filter_cnt])
123 if (fft_freqs->data[0][bin_cnt + 1] > center_freqs->data[0][filter_cnt])
129 for (; bin_cnt < win_s - 1; bin_cnt++) {
131 //checking whether last value is less than 0...
133 triangle_heights->data[0][filter_cnt] - (fft_freqs->data[0][bin_cnt] -
134 center_freqs->data[0][filter_cnt]) * riseInc;
136 filters->data[filter_cnt][bin_cnt] = val;
138 filters->data[filter_cnt][bin_cnt] = 0.0;
140 //if(fft_freqs->data[0][bin_cnt]<= upper_freqs->data[0][bin_cnt] && fft_freqs->data[0][bin_cnt+1]> upper_freqs->data[0][filter_cnt])
141 //TODO: CHECK whether bugfix correct
142 if (fft_freqs->data[0][bin_cnt + 1] > upper_freqs->data[0][filter_cnt])
148 for (; bin_cnt < win_s; bin_cnt++)
149 filters->data[filter_cnt][bin_cnt] = 0.f;
153 /* destroy temporarly allocated vectors */
155 del_fvec (lower_freqs);
156 del_fvec (upper_freqs);
157 del_fvec (center_freqs);
159 del_fvec (triangle_heights);
160 del_fvec (fft_freqs);