1 | /* |
---|
2 | Copyright (C) 2007-2009 Paul Brossier <piem@aubio.org> |
---|
3 | and Amaury Hazan <ahazan@iua.upf.edu> |
---|
4 | |
---|
5 | This file is part of Aubio. |
---|
6 | |
---|
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. |
---|
11 | |
---|
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. |
---|
16 | |
---|
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/>. |
---|
19 | |
---|
20 | */ |
---|
21 | |
---|
22 | #include "aubio_priv.h" |
---|
23 | #include "fvec.h" |
---|
24 | #include "cvec.h" |
---|
25 | #include "spectral/filterbank.h" |
---|
26 | #include "mathutils.h" |
---|
27 | |
---|
28 | void |
---|
29 | aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, uint_t samplerate, |
---|
30 | smpl_t freq_min, smpl_t freq_max) |
---|
31 | { |
---|
32 | |
---|
33 | fvec_t *filters = aubio_filterbank_get_coeffs (fb); |
---|
34 | uint_t n_filters = filters->channels, win_s = filters->length; |
---|
35 | |
---|
36 | //slaney params |
---|
37 | smpl_t lowestFrequency = 133.3333; |
---|
38 | smpl_t linearSpacing = 66.66666666; |
---|
39 | smpl_t logSpacing = 1.0711703; |
---|
40 | |
---|
41 | uint_t linearFilters = 13; |
---|
42 | uint_t logFilters = 27; |
---|
43 | uint_t allFilters = linearFilters + logFilters; |
---|
44 | |
---|
45 | //buffers for computing filter frequencies |
---|
46 | fvec_t *freqs = new_fvec (allFilters + 2, 1); |
---|
47 | |
---|
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); |
---|
51 | |
---|
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); |
---|
55 | |
---|
56 | uint_t filter_cnt, bin_cnt; |
---|
57 | |
---|
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; |
---|
61 | } |
---|
62 | smpl_t lastlinearCF = freqs->data[0][filter_cnt - 1]; |
---|
63 | |
---|
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)); |
---|
68 | } |
---|
69 | |
---|
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 |
---|
72 | |
---|
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]; |
---|
77 | } |
---|
78 | |
---|
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]); |
---|
84 | } |
---|
85 | |
---|
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]); |
---|
92 | |
---|
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); |
---|
96 | } |
---|
97 | |
---|
98 | //building each filter table |
---|
99 | for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) { |
---|
100 | |
---|
101 | //TODO:check special case : lower freq =0 |
---|
102 | //calculating rise increment in mag/Hz |
---|
103 | smpl_t riseInc = |
---|
104 | triangle_heights->data[0][filter_cnt] / |
---|
105 | (center_freqs->data[0][filter_cnt] - lower_freqs->data[0][filter_cnt]); |
---|
106 | |
---|
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]) { |
---|
112 | break; |
---|
113 | } |
---|
114 | } |
---|
115 | bin_cnt++; |
---|
116 | |
---|
117 | //positive slope |
---|
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]) |
---|
124 | break; |
---|
125 | } |
---|
126 | //bin_cnt++; |
---|
127 | |
---|
128 | //negative slope |
---|
129 | for (; bin_cnt < win_s - 1; bin_cnt++) { |
---|
130 | |
---|
131 | //checking whether last value is less than 0... |
---|
132 | smpl_t val = |
---|
133 | triangle_heights->data[0][filter_cnt] - (fft_freqs->data[0][bin_cnt] - |
---|
134 | center_freqs->data[0][filter_cnt]) * riseInc; |
---|
135 | if (val >= 0) |
---|
136 | filters->data[filter_cnt][bin_cnt] = val; |
---|
137 | else |
---|
138 | filters->data[filter_cnt][bin_cnt] = 0.0; |
---|
139 | |
---|
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]) |
---|
143 | break; |
---|
144 | } |
---|
145 | //bin_cnt++; |
---|
146 | |
---|
147 | //zeroing tail |
---|
148 | for (; bin_cnt < win_s; bin_cnt++) |
---|
149 | filters->data[filter_cnt][bin_cnt] = 0.f; |
---|
150 | |
---|
151 | } |
---|
152 | |
---|
153 | /* destroy temporarly allocated vectors */ |
---|
154 | del_fvec (freqs); |
---|
155 | del_fvec (lower_freqs); |
---|
156 | del_fvec (upper_freqs); |
---|
157 | del_fvec (center_freqs); |
---|
158 | |
---|
159 | del_fvec (triangle_heights); |
---|
160 | del_fvec (fft_freqs); |
---|
161 | |
---|
162 | } |
---|