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comparison lib/libavutil/audio_fifo.h @ 2134:992d2e6f907d

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preparation for libavcodec
author zipi
date Tue, 31 Dec 2013 14:52:14 +0000
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2133:e378232bfd36 2134:992d2e6f907d
1 /*
2 * Audio FIFO
3 * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav 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 GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Audio FIFO Buffer
25 */
26
27 #ifndef AVUTIL_AUDIO_FIFO_H
28 #define AVUTIL_AUDIO_FIFO_H
29
30 #include "avutil.h"
31 #include "fifo.h"
32 #include "samplefmt.h"
33
34 /**
35 * @addtogroup lavu_audio
36 * @{
37 */
38
39 /**
40 * Context for an Audio FIFO Buffer.
41 *
42 * - Operates at the sample level rather than the byte level.
43 * - Supports multiple channels with either planar or packed sample format.
44 * - Automatic reallocation when writing to a full buffer.
45 */
46 typedef struct AVAudioFifo AVAudioFifo;
47
48 /**
49 * Free an AVAudioFifo.
50 *
51 * @param af AVAudioFifo to free
52 */
53 void av_audio_fifo_free(AVAudioFifo *af);
54
55 /**
56 * Allocate an AVAudioFifo.
57 *
58 * @param sample_fmt sample format
59 * @param channels number of channels
60 * @param nb_samples initial allocation size, in samples
61 * @return newly allocated AVAudioFifo, or NULL on error
62 */
63 AVAudioFifo *av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels,
64 int nb_samples);
65
66 /**
67 * Reallocate an AVAudioFifo.
68 *
69 * @param af AVAudioFifo to reallocate
70 * @param nb_samples new allocation size, in samples
71 * @return 0 if OK, or negative AVERROR code on failure
72 */
73 int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples);
74
75 /**
76 * Write data to an AVAudioFifo.
77 *
78 * The AVAudioFifo will be reallocated automatically if the available space
79 * is less than nb_samples.
80 *
81 * @see enum AVSampleFormat
82 * The documentation for AVSampleFormat describes the data layout.
83 *
84 * @param af AVAudioFifo to write to
85 * @param data audio data plane pointers
86 * @param nb_samples number of samples to write
87 * @return number of samples actually written, or negative AVERROR
88 * code on failure. If successful, the number of samples
89 * actually written will always be nb_samples.
90 */
91 int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples);
92
93 /**
94 * Read data from an AVAudioFifo.
95 *
96 * @see enum AVSampleFormat
97 * The documentation for AVSampleFormat describes the data layout.
98 *
99 * @param af AVAudioFifo to read from
100 * @param data audio data plane pointers
101 * @param nb_samples number of samples to read
102 * @return number of samples actually read, or negative AVERROR code
103 * on failure. The number of samples actually read will not
104 * be greater than nb_samples, and will only be less than
105 * nb_samples if av_audio_fifo_size is less than nb_samples.
106 */
107 int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples);
108
109 /**
110 * Drain data from an AVAudioFifo.
111 *
112 * Removes the data without reading it.
113 *
114 * @param af AVAudioFifo to drain
115 * @param nb_samples number of samples to drain
116 * @return 0 if OK, or negative AVERROR code on failure
117 */
118 int av_audio_fifo_drain(AVAudioFifo *af, int nb_samples);
119
120 /**
121 * Reset the AVAudioFifo buffer.
122 *
123 * This empties all data in the buffer.
124 *
125 * @param af AVAudioFifo to reset
126 */
127 void av_audio_fifo_reset(AVAudioFifo *af);
128
129 /**
130 * Get the current number of samples in the AVAudioFifo available for reading.
131 *
132 * @param af the AVAudioFifo to query
133 * @return number of samples available for reading
134 */
135 int av_audio_fifo_size(AVAudioFifo *af);
136
137 /**
138 * Get the current number of samples in the AVAudioFifo available for writing.
139 *
140 * @param af the AVAudioFifo to query
141 * @return number of samples available for writing
142 */
143 int av_audio_fifo_space(AVAudioFifo *af);
144
145 /**
146 * @}
147 */
148
149 #endif /* AVUTIL_AUDIO_FIFO_H */