source: src/musicutils.h @ 986131d

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretch
Last change on this file since 986131d was 986131d, checked in by Eduard Müller <mueller.eduard@googlemail.com>, 3 years ago

Intel IPP support for aubio

See emuell/aubio/ intel_ipp2 for details please

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1/*
2  Copyright (C) 2003-2015 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  \param window_type type of the window to create
35  \param size length of the window to create (see fvec_set_window())
36
37*/
38fvec_t *new_aubio_window (char_t * window_type, uint_t size);
39
40/** set elements of a vector to window coefficients
41
42  \param window exsting ::fvec_t to use
43  \param window_type type of the window to create
44
45  List of available window types: "rectangle", "hamming", "hanning",
46  "hanningz", "blackman", "blackman_harris", "gaussian", "welch", "parzen",
47  "default".
48
49  "default" is equivalent to "hanningz".
50
51  References:
52
53    - <a href="http://en.wikipedia.org/wiki/Window_function">Window
54function</a> on Wikipedia
55    - Amalia de Götzen, Nicolas Bernardini, and Daniel Arfib. Traditional (?)
56implementations of a phase vocoder: the tricks of the trade. In Proceedings of
57the International Conference on Digital Audio Effects (DAFx-00), pages 37–44,
58Uni- versity of Verona, Italy, 2000.
59  (<a href="http://www.cs.princeton.edu/courses/archive/spr09/cos325/Bernardini.pdf">
60  pdf</a>)
61
62 */
63uint_t fvec_set_window (fvec_t * window, char_t * window_type);
64
65/** compute the principal argument
66
67  This function maps the input phase to its corresponding value wrapped in the
68range \f$ [-\pi, \pi] \f$.
69
70  \param phase unwrapped phase to map to the unit circle
71
72  \return equivalent phase wrapped to the unit circle
73
74*/
75smpl_t aubio_unwrap2pi (smpl_t phase);
76
77/** convert frequency bin to midi value */
78smpl_t aubio_bintomidi (smpl_t bin, smpl_t samplerate, smpl_t fftsize);
79
80/** convert midi value to frequency bin */
81smpl_t aubio_miditobin (smpl_t midi, smpl_t samplerate, smpl_t fftsize);
82
83/** convert frequency bin to frequency (Hz) */
84smpl_t aubio_bintofreq (smpl_t bin, smpl_t samplerate, smpl_t fftsize);
85
86/** convert frequency (Hz) to frequency bin */
87smpl_t aubio_freqtobin (smpl_t freq, smpl_t samplerate, smpl_t fftsize);
88
89/** convert frequency (Hz) to midi value (0-128) */
90smpl_t aubio_freqtomidi (smpl_t freq);
91
92/** convert midi value (0-128) to frequency (Hz) */
93smpl_t aubio_miditofreq (smpl_t midi);
94
95/** initialize global status at beginning of program
96
97  This function should be used before doing anything else in aubio.
98  So far it is only used to initialize the Intel IPP library, when it's used.
99*/
100void aubio_init (void);
101
102/** clean up cached memory at the end of program
103
104  This function should be used at the end of programs to purge all cached
105  memory. So far it is only useful to clean FFTW's cache.
106
107*/
108void aubio_cleanup (void);
109
110/** zero-crossing rate (ZCR)
111
112  The zero-crossing rate is the number of times a signal changes sign,
113  divided by the length of this signal.
114
115  \param v vector to compute ZCR from
116
117  \return zero-crossing rate of v
118
119*/
120smpl_t aubio_zero_crossing_rate (fvec_t * v);
121
122/** compute sound level on a linear scale
123
124  This gives the average of the square amplitudes.
125
126  \param v vector to compute level from
127
128  \return level of v
129
130*/
131smpl_t aubio_level_lin (const fvec_t * v);
132
133/** compute sound pressure level (SPL) in dB
134
135  This quantity is often wrongly called 'loudness'.
136
137  This gives ten times the log10 of the average of the square amplitudes.
138
139  \param v vector to compute dB SPL from
140
141  \return level of v in dB SPL
142
143*/
144smpl_t aubio_db_spl (const fvec_t * v);
145
146/** check if buffer level in dB SPL is under a given threshold
147
148  \param v vector to get level from
149  \param threshold threshold in dB SPL
150
151  \return 0 if level is under the given threshold, 1 otherwise
152
153*/
154uint_t aubio_silence_detection (const fvec_t * v, smpl_t threshold);
155
156/** get buffer level if level >= threshold, 1. otherwise
157
158  \param v vector to get level from
159  \param threshold threshold in dB SPL
160
161  \return level in dB SPL if level >= threshold, 1. otherwise
162
163*/
164smpl_t aubio_level_detection (const fvec_t * v, smpl_t threshold);
165
166/** clamp the values of a vector within the range [-abs(max), abs(max)]
167
168  \param in vector to clamp
169  \param absmax maximum value over which input vector elements should be clamped
170
171*/
172void fvec_clamp(fvec_t *in, smpl_t absmax);
173
174#ifdef __cplusplus
175}
176#endif
177
178#endif /* AUBIO_MUSICUTILS_H */
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