source: src/spectral/filterbank_mel.c @ cfd35db

feature/autosinkfeature/cnnfeature/cnn_orgfeature/constantqfeature/crepefeature/crepe_orgfeature/pitchshiftfeature/pydocstringsfeature/timestretchfix/ffmpeg5pitchshiftsamplertimestretchyinfft+
Last change on this file since cfd35db was cfd35db, checked in by Paul Brossier <piem@piem.org>, 15 years ago

src/spectral/filterbank_mel.{c,h}: indent

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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
28void
29aubio_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}
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