source: src/spectral/filterbank.h @ d91fa83

feature/cnnfeature/crepe
Last change on this file since d91fa83 was 6b46a4e, checked in by Paul Brossier <piem@piem.org>, 6 years ago

[filterbank] add docs for norm and power

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File size: 3.6 KB
Line 
1/*
2  Copyright (C) 2007-2013 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/** \file
23
24  Filterbank object
25
26  General-purpose spectral filterbank object.
27
28  \example spectral/test-filterbank.c
29
30*/
31
32#ifndef AUBIO_FILTERBANK_H
33#define AUBIO_FILTERBANK_H
34
35#ifdef __cplusplus
36extern "C"
37{
38#endif
39
40/** filterbank object
41
42  This object stores a matrix of spectral filter coefficients.
43
44 */
45typedef struct _aubio_filterbank_t aubio_filterbank_t;
46
47/** create filterbank object
48
49  \param n_filters number of filters to create
50  \param win_s size of analysis buffer (and length the FFT transform)
51
52*/
53aubio_filterbank_t *new_aubio_filterbank (uint_t n_filters, uint_t win_s);
54
55/** destroy filterbank object
56
57  \param f filterbank object, as returned by new_aubio_filterbank()
58
59*/
60void del_aubio_filterbank (aubio_filterbank_t * f);
61
62/** compute filterbank
63
64  \param f filterbank object, as returned by new_aubio_filterbank()
65  \param in input spectrum containing an input spectrum of length `win_s`
66  \param out output vector containing the energy found in each band, `nfilt` output values
67
68*/
69void aubio_filterbank_do (aubio_filterbank_t * f, const cvec_t * in, fvec_t * out);
70
71/** return a pointer to the matrix object containing all filter coefficients
72
73  \param f filterbank object, as returned by new_aubio_filterbank()
74
75 */
76fmat_t *aubio_filterbank_get_coeffs (const aubio_filterbank_t * f);
77
78/** copy filter coefficients to the filterbank
79
80  \param f filterbank object, as returned by new_aubio_filterbank()
81  \param filters filter bank coefficients to copy from
82
83 */
84uint_t aubio_filterbank_set_coeffs (aubio_filterbank_t * f, const fmat_t * filters);
85
86/** set norm parameter
87
88  \param f filterbank object, as returned by new_aubio_filterbank()
89  \param norm `1` to norm the filters, `0` otherwise.
90
91  If set to `0`, the filters will not be normalized. If set to `1`,
92  each filter will be normalized to one. Defaults to `1`.
93
94  This function should be called *before* setting the filters with one of
95  aubio_filterbank_set_triangle_bands(), aubio_filterbank_set_mel_coeffs(),
96  aubio_filterbank_set_mel_coeffs_htk(), or
97  aubio_filterbank_set_mel_coeffs_slaney().
98
99 */
100uint_t aubio_filterbank_set_norm (aubio_filterbank_t *f, smpl_t norm);
101
102/** get norm parameter
103
104  \param f filterbank object, as returned by new_aubio_filterbank()
105  \returns `1` if norm is set, `0` otherwise. Defaults to `1`.
106
107 */
108smpl_t aubio_filterbank_get_norm (aubio_filterbank_t *f);
109
110/** set power parameter
111
112  \param f filterbank object, as returned by new_aubio_filterbank()
113  \param power Raise norm of the input spectrum norm to this power before
114  computing filterbank.  Defaults to `1`.
115
116 */
117uint_t aubio_filterbank_set_power (aubio_filterbank_t *f, smpl_t power);
118
119/** get power parameter
120
121  \param f filterbank object, as returned by new_aubio_filterbank()
122  \return current power parameter. Defaults to `1`.
123
124 */
125smpl_t aubio_filterbank_get_power (aubio_filterbank_t *f);
126
127#ifdef __cplusplus
128}
129#endif
130
131#endif /* AUBIO_FILTERBANK_H */
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