source: src/musicutils.h @ 4ed0ed1

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretchpitchshiftsamplertimestretchyinfft+
Last change on this file since 4ed0ed1 was b235c0e, checked in by Paul Brossier <piem@piem.org>, 6 years ago

src/: sync header defines, remove trailing spaces, update copyrights

Signed-off-by: Paul Brossier <piem@piem.org>

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1/*
2  Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
3
4  This file is part of aubio.
5
6  aubio is free software: you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation, either version 3 of the License, or
9  (at your option) any later version.
10
11  aubio is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  GNU General Public License for more details.
15
16  You should have received a copy of the GNU General Public License
17  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
18
19*/
20
21/** @file
22 *  various functions useful in audio signal processing
23 */
24
25#ifndef _AUBIO__MUSICUTILS_H
26#define _AUBIO__MUSICUTILS_H
27
28#ifdef __cplusplus
29extern "C" {
30#endif
31
32/** create window
33 
34  References:
35   
36    - <a href="http://en.wikipedia.org/wiki/Window_function">Window
37function</a> on Wikipedia
38    - Amalia de Götzen, Nicolas Bernardini, and Daniel Arfib. Traditional (?)
39implementations of a phase vocoder: the tricks of the trade. In Proceedings of
40the International Conference on Digital Audio Effects (DAFx-00), pages 37–44,
41Uni- versity of Verona, Italy, 2000.
42  (<a href="http://profs.sci.univr.it/%7Edafx/Final-Papers/ps/Bernardini.ps.gz">
43  ps.gz</a>)
44
45*/
46fvec_t *new_aubio_window (char_t * window_type, uint_t size);
47
48/** set elements of a vector to window coefficients
49
50 */
51uint_t fvec_set_window (fvec_t * window, char_t * window_type);
52
53/** compute the principal argument
54
55  This function maps the input phase to its corresponding value wrapped in the
56range \f$ [-\pi, \pi] \f$.
57
58  \param phase unwrapped phase to map to the unit circle
59 
60  \return equivalent phase wrapped to the unit circle
61
62*/
63smpl_t aubio_unwrap2pi (smpl_t phase);
64
65/** convert frequency bin to midi value */
66smpl_t aubio_bintomidi (smpl_t bin, smpl_t samplerate, smpl_t fftsize);
67
68/** convert midi value to frequency bin */
69smpl_t aubio_miditobin (smpl_t midi, smpl_t samplerate, smpl_t fftsize);
70
71/** convert frequency bin to frequency (Hz) */
72smpl_t aubio_bintofreq (smpl_t bin, smpl_t samplerate, smpl_t fftsize);
73
74/** convert frequency (Hz) to frequency bin */
75smpl_t aubio_freqtobin (smpl_t freq, smpl_t samplerate, smpl_t fftsize);
76
77/** convert frequency (Hz) to midi value (0-128) */
78smpl_t aubio_freqtomidi (smpl_t freq);
79
80/** convert midi value (0-128) to frequency (Hz) */
81smpl_t aubio_miditofreq (smpl_t midi);
82
83/** clean up cached memory at the end of program
84 
85  This function should be used at the end of programs to purge all cached
86  memory. So far it is only useful to clean FFTW's cache.
87
88*/
89void aubio_cleanup (void);
90
91/** zero-crossing rate (ZCR)
92
93  The zero-crossing rate is the number of times a signal changes sign,
94  divided by the length of this signal.
95
96  \param v vector to compute ZCR from
97
98  \return zero-crossing rate of v
99
100*/
101smpl_t aubio_zero_crossing_rate (fvec_t * v);
102
103/** compute sound level on a linear
104
105  This gives the average of the square amplitudes.
106
107  \param v vector to compute dB SPL from
108
109  \return level of v
110
111*/
112smpl_t aubio_level_lin (fvec_t * v);
113
114/** compute sound pressure level (SPL) in dB
115
116  This quantity is often wrongly called 'loudness'.
117
118  This gives ten times the log10 of the average of the square amplitudes.
119
120  \param v vector to compute dB SPL from
121
122  \return level of v in dB SPL
123
124*/
125smpl_t aubio_db_spl (fvec_t * v);
126
127/** check if buffer level in dB SPL is under a given threshold
128 
129  \param v vector to get level from
130  \param threshold threshold in dB SPL
131
132  \return 0 if level is under the given threshold, 1 otherwise
133
134*/
135uint_t aubio_silence_detection (fvec_t * v, smpl_t threshold);
136
137/** get buffer level if level >= threshold, 1. otherwise
138
139  \param v vector to get level from
140  \param threshold threshold in dB SPL
141
142  \return level in dB SPL if level >= threshold, 1. otherwise
143
144*/
145smpl_t aubio_level_detection (fvec_t * v, smpl_t threshold);
146
147#ifdef __cplusplus
148}
149#endif
150
151#endif /* _AUBIO__MUSICUTILS_H */
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