aubio: spectral/filterbank.h Source File

aubio 0.4.9

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filterbank.h
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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 */
45 typedef 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*/
53 aubio_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*/
60 void 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*/
69 void 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 */
76 fmat_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 */
84 uint_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 */
100 uint_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 */
108 smpl_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 */
117 uint_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 */
125 smpl_t aubio_filterbank_get_power (aubio_filterbank_t *f);
126
127#ifdef __cplusplus
128}
129#endif
130
131#endif /* AUBIO_FILTERBANK_H */
aubio_filterbank_set_power
uint_t aubio_filterbank_set_power(aubio_filterbank_t *f, smpl_t power)
set power parameter
aubio_filterbank_get_norm
smpl_t aubio_filterbank_get_norm(aubio_filterbank_t *f)
get norm parameter
del_aubio_filterbank
void del_aubio_filterbank(aubio_filterbank_t *f)
destroy filterbank object
aubio_filterbank_set_norm
uint_t aubio_filterbank_set_norm(aubio_filterbank_t *f, smpl_t norm)
set norm parameter
new_aubio_filterbank
aubio_filterbank_t * new_aubio_filterbank(uint_t n_filters, uint_t win_s)
create filterbank object
aubio_filterbank_get_coeffs
fmat_t * aubio_filterbank_get_coeffs(const aubio_filterbank_t *f)
return a pointer to the matrix object containing all filter coefficients
aubio_filterbank_t
struct _aubio_filterbank_t aubio_filterbank_t
filterbank object
Definition filterbank.h:45
aubio_filterbank_set_coeffs
uint_t aubio_filterbank_set_coeffs(aubio_filterbank_t *f, const fmat_t *filters)
copy filter coefficients to the filterbank
aubio_filterbank_do
void aubio_filterbank_do(aubio_filterbank_t *f, const cvec_t *in, fvec_t *out)
compute filterbank
aubio_filterbank_get_power
smpl_t aubio_filterbank_get_power(aubio_filterbank_t *f)
get power parameter
cvec_t
Vector of real-valued phase and spectrum data.
Definition cvec.h:63
fmat_t
Buffer for real data.
Definition fmat.h:40
fvec_t
Buffer for real data.
Definition fvec.h:67
uint_t
unsigned int uint_t
unsigned integer
Definition types.h:60
smpl_t
float smpl_t
short sample format (32 or 64 bits)
Definition types.h:41