aubio  0.4.0~beta1
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source.h
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1 /*
2  Copyright (C) 2012-2013 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 #ifndef _AUBIO_SOURCE_H
22 #define _AUBIO_SOURCE_H
23 
24 /** \file
25 
26  Media source to read blocks of consecutive audio samples from file
27 
28  Depending on how aubio was compiled, the following file formats will be
29  available.
30 
31  To write to file, use ::aubio_sink_t.
32 
33  \b \p source_avcodec : libav
34 
35  aubio can be optionally compiled with [libav](http://libav.org), which can
36  read from a very large number of audio and video formats, including over
37  different network protocols such as HTTP.
38 
39  \b \p source_apple_audio : ExtAudioFileRef
40 
41  On Mac and iOS platforms, aubio should be compiled with CoreAudio [Extended
42  Audio File Services]
43  (https://developer.apple.com/library/mac/documentation/musicaudio/CAAudioTooboxRef/_index.html).
44  This provides access to most common audio file formats, including compressed
45  ones.
46 
47  \b \p source_sndfile : libsndfile
48 
49  Also optional, aubio can be built against
50  [libsndfile](http://www.mega-nerd.com/libsndfile/), which can read [most
51  uncompressed formats](http://www.mega-nerd.com/libsndfile/#Features).
52 
53  \example io/test-source.c
54  \example io/test-source_multi.c
55 
56 */
57 
58 #ifdef __cplusplus
59 extern "C" {
60 #endif
61 
62 /** media source object */
63 typedef struct _aubio_source_t aubio_source_t;
64 
65 /**
66 
67  create new ::aubio_source_t
68 
69  \param uri the file path or uri to read from
70  \param samplerate sampling rate to view the fie at
71  \param hop_size the size of the blocks to read from
72 
73  Creates a new source object. If `0` is passed as `samplerate`, the sample
74  rate of the original file is used.
75 
76  The samplerate of newly created source can be obtained using
77  ::aubio_source_get_samplerate.
78 
79 */
80 aubio_source_t * new_aubio_source(char_t * uri, uint_t samplerate, uint_t hop_size);
81 
82 /**
83 
84  read monophonic vector of length hop_size from source object
85 
86  \param s source object, created with ::new_aubio_source
87  \param read_to ::fvec_t of data to read to
88  \param read upon returns, equals to number of frames actually read
89 
90  Upon returns, `read` contains the number of frames actually read from the
91  source. `hop_size` if enough frames could be read, less otherwise.
92 
93 */
94 void aubio_source_do(aubio_source_t * s, fvec_t * read_to, uint_t * read);
95 
96 /**
97 
98  read polyphonic vector of length hop_size from source object
99 
100  \param s source object, created with ::new_aubio_source
101  \param read_to ::fmat_t of data to read to
102  \param[out] read upon returns, equals to number of frames actually read
103 
104  Upon returns, `read` contains the number of frames actually read from the
105  source. `hop_size` if enough frames could be read, less otherwise.
106 
107 */
108 void aubio_source_do_multi(aubio_source_t * s, fmat_t * read_to, uint_t * read);
109 
110 /**
111 
112  get samplerate of source object
113 
114  \param s source object, created with ::new_aubio_source
115  \return samplerate, in Hz
116 
117 */
118 uint_t aubio_source_get_samplerate(aubio_source_t * s);
119 
120 /**
121 
122  get channels of source object
123 
124  \param s source object, created with ::new_aubio_source
125  \return channels
126 
127 */
128 uint_t aubio_source_get_channels (aubio_source_t * s);
129 
130 /**
131 
132  seek source object
133 
134  \param s source object, created with ::new_aubio_source
135  \param pos position to seek to, in frames
136 
137  \return 0 if sucessful, non-zero on failure
138 
139 */
140 uint_t aubio_source_seek (aubio_source_t * s, uint_t pos);
141 
142 /**
143 
144  close source and cleanup memory
145 
146  \param s source object, created with ::new_aubio_source
147 
148 */
149 void del_aubio_source(aubio_source_t * s);
150 
151 #ifdef __cplusplus
152 }
153 #endif
154 
155 #endif /* _AUBIO_SOURCE_H */
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