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"
28 void aubio_filterbank_set_mel_coeffs(aubio_filterbank_t *fb, uint_t samplerate, smpl_t freq_min, smpl_t freq_max){
30 fvec_t *filters = aubio_filterbank_get_coeffs(fb);
31 uint_t n_filters = filters->channels, win_s = filters->length;
34 smpl_t lowestFrequency = 133.3333;
35 smpl_t linearSpacing = 66.66666666;
36 smpl_t logSpacing = 1.0711703;
38 uint_t linearFilters = 13;
39 uint_t logFilters = 27;
40 uint_t allFilters = linearFilters + logFilters;
42 //buffers for computing filter frequencies
43 fvec_t * freqs=new_fvec(allFilters+2 , 1);
45 fvec_t * lower_freqs=new_fvec( allFilters, 1);
46 fvec_t * upper_freqs=new_fvec( allFilters, 1);
47 fvec_t * center_freqs=new_fvec( allFilters, 1);
49 fvec_t * triangle_heights=new_fvec( allFilters, 1);
50 //lookup table of each bin frequency in hz
51 fvec_t * fft_freqs=new_fvec(win_s, 1);
53 uint_t filter_cnt, bin_cnt;
55 //first step: filling all the linear filter frequencies
56 for(filter_cnt=0; filter_cnt<linearFilters; filter_cnt++){
57 freqs->data[0][filter_cnt]=lowestFrequency+ filter_cnt*linearSpacing;
59 smpl_t lastlinearCF=freqs->data[0][filter_cnt-1];
61 //second step: filling all the log filter frequencies
62 for(filter_cnt=0; filter_cnt<logFilters+2; filter_cnt++){
63 freqs->data[0][filter_cnt+linearFilters] =
64 lastlinearCF*(pow(logSpacing,filter_cnt+1));
67 //Option 1. copying interesting values to lower_freqs, center_freqs and upper freqs arrays
68 //TODO: would be nicer to have a reference to freqs->data, anyway we do not care in this init step
70 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
71 lower_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt];
72 center_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+1];
73 upper_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+2];
76 //computing triangle heights so that each triangle has unit area
77 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
78 triangle_heights->data[0][filter_cnt] = 2./(upper_freqs->data[0][filter_cnt]
79 - lower_freqs->data[0][filter_cnt]);
82 //AUBIO_DBG("filter tables frequencies\n");
83 //for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++)
84 // AUBIO_DBG("filter n. %d %f %f %f %f\n",
85 // filter_cnt, lower_freqs->data[0][filter_cnt],
86 // center_freqs->data[0][filter_cnt], upper_freqs->data[0][filter_cnt],
87 // triangle_heights->data[0][filter_cnt]);
89 //filling the fft_freqs lookup table, which assigns the frequency in hz to each bin
90 for(bin_cnt=0; bin_cnt<win_s; bin_cnt++){
91 fft_freqs->data[0][bin_cnt]= aubio_bintofreq(bin_cnt, samplerate, win_s);
94 //building each filter table
95 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
97 //TODO:check special case : lower freq =0
98 //calculating rise increment in mag/Hz
99 smpl_t riseInc= triangle_heights->data[0][filter_cnt]/(center_freqs->data[0][filter_cnt]-lower_freqs->data[0][filter_cnt]);
101 //zeroing begining of filter
102 for(bin_cnt=0; bin_cnt<win_s-1; bin_cnt++){
103 filters->data[filter_cnt][bin_cnt]=0.0;
104 if( fft_freqs->data[0][bin_cnt] <= lower_freqs->data[0][filter_cnt] &&
105 fft_freqs->data[0][bin_cnt+1] > lower_freqs->data[0][filter_cnt]) {
112 for(; bin_cnt<win_s-1; bin_cnt++){
113 filters->data[filter_cnt][bin_cnt]=(fft_freqs->data[0][bin_cnt]-lower_freqs->data[0][filter_cnt])*riseInc;
114 //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])
115 if(fft_freqs->data[0][bin_cnt+1]> center_freqs->data[0][filter_cnt])
121 for(; bin_cnt<win_s-1; bin_cnt++){
123 //checking whether last value is less than 0...
124 smpl_t val=triangle_heights->data[0][filter_cnt]-(fft_freqs->data[0][bin_cnt]-center_freqs->data[0][filter_cnt])*riseInc;
126 filters->data[filter_cnt][bin_cnt]=val;
127 else filters->data[filter_cnt][bin_cnt]=0.0;
129 //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])
130 //TODO: CHECK whether bugfix correct
131 if(fft_freqs->data[0][bin_cnt+1]> upper_freqs->data[0][filter_cnt])
137 for(; bin_cnt<win_s; bin_cnt++)
138 filters->data[filter_cnt][bin_cnt]=0.f;
142 /* destroy temporarly allocated vectors */
144 del_fvec(lower_freqs);
145 del_fvec(upper_freqs);
146 del_fvec(center_freqs);
148 del_fvec(triangle_heights);