source: src/spectral/filterbank.c @ d37400c

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretchpitchshiftsamplertimestretchyinfft+
Last change on this file since d37400c was d37400c, checked in by Paul Brossier <piem@piem.org>, 11 years ago

src/spectral/filterbank.c: move log10 to mfcc.c

  • Property mode set to 100644
File size: 2.2 KB
Line 
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/** \brief A structure to store a set of n_filters filters of lenghts win_s */
29struct aubio_filterbank_t_
30{
31  uint_t win_s;
32  uint_t n_filters;
33  fvec_t *filters;
34};
35
36aubio_filterbank_t *
37new_aubio_filterbank (uint_t n_filters, uint_t win_s)
38{
39  /* allocate space for filterbank object */
40  aubio_filterbank_t *fb = AUBIO_NEW (aubio_filterbank_t);
41  fb->win_s = win_s;
42  fb->n_filters = n_filters;
43
44  /* allocate filter tables, an fvec of length win_s and of filter_cnt channel */
45  fb->filters = new_fvec (win_s / 2 + 1, n_filters);
46
47  return fb;
48}
49
50void
51del_aubio_filterbank (aubio_filterbank_t * fb)
52{
53  del_fvec (fb->filters);
54  AUBIO_FREE (fb);
55}
56
57void
58aubio_filterbank_do (aubio_filterbank_t * f, cvec_t * in, fvec_t * out)
59{
60  uint_t i, j, fn;
61
62  /* apply filter to all input channel, provided out has enough channels */
63  uint_t max_channels = MIN (in->channels, out->channels);
64  uint_t max_filters = MIN (f->n_filters, out->length);
65
66  /* reset all values in output vector */
67  fvec_zeros (out);
68
69  /* apply filters on all channels */
70  for (i = 0; i < max_channels; i++) {
71
72    /* for each filter */
73    for (fn = 0; fn < max_filters; fn++) {
74
75      /* for each sample */
76      for (j = 0; j < in->length; j++) {
77        out->data[i][fn] += in->norm[i][j] * f->filters->data[fn][j];
78      }
79    }
80  }
81
82  return;
83}
84
85fvec_t *
86aubio_filterbank_get_coeffs (aubio_filterbank_t * f)
87{
88  return f->filters;
89}
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