2 Copyright (C) 2007 Amaury Hazan <ahazan@iua.upf.edu>
3 and Paul Brossier <piem@piem.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include "aubio_priv.h"
25 #include "spectral/filterbank.h"
26 #include "mathutils.h"
28 #define VERY_SMALL_NUMBER 2e-42
30 /** \brief A structure to store a set of n_filters filters of lenghts win_s */
31 struct aubio_filterbank_t_ {
37 aubio_filterbank_t * new_aubio_filterbank(uint_t n_filters, uint_t win_s){
38 /** allocating space for filterbank object */
39 aubio_filterbank_t * fb = AUBIO_NEW(aubio_filterbank_t);
42 fb->n_filters=n_filters;
44 /** allocating filter tables */
45 fb->filters=AUBIO_ARRAY(fvec_t*,n_filters);
46 for (filter_cnt=0; filter_cnt<n_filters; filter_cnt++)
47 /* considering one-channel filters */
48 fb->filters[filter_cnt]=new_fvec(win_s, 1);
54 FB initialization based on Slaney's auditory toolbox
56 *solve memory leak problems while
57 *solve quantization issues when constructing signal:
59 *corrections for win_s=1024 -> why even filters with smaller amplitude
63 aubio_filterbank_t * new_aubio_filterbank_mfcc(uint_t n_filters, uint_t win_s, uint_t samplerate, smpl_t freq_min, smpl_t freq_max){
65 aubio_filterbank_t * fb = new_aubio_filterbank(n_filters, win_s);
69 smpl_t lowestFrequency = 133.3333;
70 smpl_t linearSpacing = 66.66666666;
71 smpl_t logSpacing = 1.0711703;
73 uint_t linearFilters = 13;
74 uint_t logFilters = 27;
75 uint_t allFilters = linearFilters + logFilters;
77 //buffers for computing filter frequencies
78 fvec_t * freqs=new_fvec(allFilters+2 , 1);
80 fvec_t * lower_freqs=new_fvec( allFilters, 1);
81 fvec_t * upper_freqs=new_fvec( allFilters, 1);
82 fvec_t * center_freqs=new_fvec( allFilters, 1);
84 fvec_t * triangle_heights=new_fvec( allFilters, 1);
85 //lookup table of each bin frequency in hz
86 fvec_t * fft_freqs=new_fvec(win_s, 1);
88 uint_t filter_cnt, bin_cnt;
90 //first step: filling all the linear filter frequencies
91 for(filter_cnt=0; filter_cnt<linearFilters; filter_cnt++){
92 freqs->data[0][filter_cnt]=lowestFrequency+ filter_cnt*linearSpacing;
94 smpl_t lastlinearCF=freqs->data[0][filter_cnt-1];
96 //second step: filling all the log filter frequencies
97 for(filter_cnt=0; filter_cnt<logFilters+2; filter_cnt++){
98 freqs->data[0][filter_cnt+linearFilters] =
99 lastlinearCF*(pow(logSpacing,filter_cnt+1));
102 //Option 1. copying interesting values to lower_freqs, center_freqs and upper freqs arrays
103 //TODO: would be nicer to have a reference to freqs->data, anyway we do not care in this init step
105 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
106 lower_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt];
107 center_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+1];
108 upper_freqs->data[0][filter_cnt]=freqs->data[0][filter_cnt+2];
111 //computing triangle heights so that each triangle has unit area
112 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
113 triangle_heights->data[0][filter_cnt] = 2./(upper_freqs->data[0][filter_cnt]
114 - lower_freqs->data[0][filter_cnt]);
117 //AUBIO_DBG("filter tables frequencies\n");
118 //for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++)
119 // AUBIO_DBG("filter n. %d %f %f %f %f\n",
120 // filter_cnt, lower_freqs->data[0][filter_cnt],
121 // center_freqs->data[0][filter_cnt], upper_freqs->data[0][filter_cnt],
122 // triangle_heights->data[0][filter_cnt]);
124 //filling the fft_freqs lookup table, which assigns the frequency in hz to each bin
125 for(bin_cnt=0; bin_cnt<win_s; bin_cnt++){
126 fft_freqs->data[0][bin_cnt]= aubio_bintofreq(bin_cnt, samplerate, win_s);
129 //building each filter table
130 for(filter_cnt=0; filter_cnt<allFilters; filter_cnt++){
132 //TODO:check special case : lower freq =0
133 //calculating rise increment in mag/Hz
134 smpl_t riseInc= triangle_heights->data[0][filter_cnt]/(center_freqs->data[0][filter_cnt]-lower_freqs->data[0][filter_cnt]);
136 //zeroing begining of filter
137 for(bin_cnt=0; bin_cnt<win_s-1; bin_cnt++){
138 fb->filters[filter_cnt]->data[0][bin_cnt]=0.f;
139 if( fft_freqs->data[0][bin_cnt] <= lower_freqs->data[0][filter_cnt] &&
140 fft_freqs->data[0][bin_cnt+1] > lower_freqs->data[0][filter_cnt]) {
147 for(; bin_cnt<win_s-1; bin_cnt++){
148 fb->filters[filter_cnt]->data[0][bin_cnt]=(fft_freqs->data[0][bin_cnt]-lower_freqs->data[0][filter_cnt])*riseInc;
149 //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])
150 if(fft_freqs->data[0][bin_cnt+1]> center_freqs->data[0][filter_cnt])
156 for(; bin_cnt<win_s-1; bin_cnt++){
158 //checking whether last value is less than 0...
159 smpl_t val=triangle_heights->data[0][filter_cnt]-(fft_freqs->data[0][bin_cnt]-center_freqs->data[0][filter_cnt])*riseInc;
161 fb->filters[filter_cnt]->data[0][bin_cnt]=val;
162 else fb->filters[filter_cnt]->data[0][bin_cnt]=0.f;
164 //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])
165 //TODO: CHECK whether bugfix correct
166 if(fft_freqs->data[0][bin_cnt+1]> upper_freqs->data[0][filter_cnt])
172 for(; bin_cnt<win_s; bin_cnt++)
173 fb->filters[filter_cnt]->data[0][bin_cnt]=0.f;
179 del_fvec(lower_freqs);
180 del_fvec(upper_freqs);
181 del_fvec(center_freqs);
183 del_fvec(triangle_heights);
190 void del_aubio_filterbank(aubio_filterbank_t * fb){
192 /** deleting filter tables first */
193 for (filter_cnt=0; filter_cnt<fb->n_filters; filter_cnt++)
194 del_fvec(fb->filters[filter_cnt]);
195 AUBIO_FREE(fb->filters);
199 void aubio_filterbank_do(aubio_filterbank_t * f, cvec_t * in, fvec_t *out) {
200 uint_t n, filter_cnt;
201 for(filter_cnt = 0; (filter_cnt < f->n_filters)
202 && (filter_cnt < out->length); filter_cnt++){
203 out->data[0][filter_cnt] = 0.f;
204 for(n = 0; n < in->length; n++){
205 out->data[0][filter_cnt] += in->norm[0][n]
206 * f->filters[filter_cnt]->data[0][n];
208 out->data[0][filter_cnt] =
209 LOG(out->data[0][filter_cnt] < VERY_SMALL_NUMBER ?
210 VERY_SMALL_NUMBER : out->data[0][filter_cnt]);
216 fvec_t * aubio_filterbank_getchannel(aubio_filterbank_t * f, uint_t channel) {
217 if ( (channel < f->n_filters) ) { return f->filters[channel]; }
218 else { return NULL; }