FFmpeg 4.4.5
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audio_fifo.h
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1/*
2 * Audio FIFO
3 * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 * @defgroup lavu_audiofifo Audio FIFO Buffer
39 * @{
40 */
41
42/**
43 * Context for an Audio FIFO Buffer.
44 *
45 * - Operates at the sample level rather than the byte level.
46 * - Supports multiple channels with either planar or packed sample format.
47 * - Automatic reallocation when writing to a full buffer.
48 */
49typedef struct AVAudioFifo AVAudioFifo;
50
51/**
52 * Free an AVAudioFifo.
53 *
54 * @param af AVAudioFifo to free
55 */
57
58/**
59 * Allocate an AVAudioFifo.
60 *
61 * @param sample_fmt sample format
62 * @param channels number of channels
63 * @param nb_samples initial allocation size, in samples
64 * @return newly allocated AVAudioFifo, or NULL on error
65 */
66AVAudioFifo *av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels,
67 int nb_samples);
68
69/**
70 * Reallocate an AVAudioFifo.
71 *
72 * @param af AVAudioFifo to reallocate
73 * @param nb_samples new allocation size, in samples
74 * @return 0 if OK, or negative AVERROR code on failure
75 */
77int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples);
78
79/**
80 * Write data to an AVAudioFifo.
81 *
82 * The AVAudioFifo will be reallocated automatically if the available space
83 * is less than nb_samples.
84 *
85 * @see enum AVSampleFormat
86 * The documentation for AVSampleFormat describes the data layout.
87 *
88 * @param af AVAudioFifo to write to
89 * @param data audio data plane pointers
90 * @param nb_samples number of samples to write
91 * @return number of samples actually written, or negative AVERROR
92 * code on failure. If successful, the number of samples
93 * actually written will always be nb_samples.
94 */
95int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples);
96
97/**
98 * Peek data from an AVAudioFifo.
99 *
100 * @see enum AVSampleFormat
101 * The documentation for AVSampleFormat describes the data layout.
102 *
103 * @param af AVAudioFifo to read from
104 * @param data audio data plane pointers
105 * @param nb_samples number of samples to peek
106 * @return number of samples actually peek, or negative AVERROR code
107 * on failure. The number of samples actually peek will not
108 * be greater than nb_samples, and will only be less than
109 * nb_samples if av_audio_fifo_size is less than nb_samples.
110 */
111int av_audio_fifo_peek(AVAudioFifo *af, void **data, int nb_samples);
112
113/**
114 * Peek data from an AVAudioFifo.
115 *
116 * @see enum AVSampleFormat
117 * The documentation for AVSampleFormat describes the data layout.
118 *
119 * @param af AVAudioFifo to read from
120 * @param data audio data plane pointers
121 * @param nb_samples number of samples to peek
122 * @param offset offset from current read position
123 * @return number of samples actually peek, or negative AVERROR code
124 * on failure. The number of samples actually peek will not
125 * be greater than nb_samples, and will only be less than
126 * nb_samples if av_audio_fifo_size is less than nb_samples.
127 */
128int av_audio_fifo_peek_at(AVAudioFifo *af, void **data, int nb_samples, int offset);
129
130/**
131 * Read data from an AVAudioFifo.
132 *
133 * @see enum AVSampleFormat
134 * The documentation for AVSampleFormat describes the data layout.
135 *
136 * @param af AVAudioFifo to read from
137 * @param data audio data plane pointers
138 * @param nb_samples number of samples to read
139 * @return number of samples actually read, or negative AVERROR code
140 * on failure. The number of samples actually read will not
141 * be greater than nb_samples, and will only be less than
142 * nb_samples if av_audio_fifo_size is less than nb_samples.
143 */
144int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples);
145
146/**
147 * Drain data from an AVAudioFifo.
148 *
149 * Removes the data without reading it.
150 *
151 * @param af AVAudioFifo to drain
152 * @param nb_samples number of samples to drain
153 * @return 0 if OK, or negative AVERROR code on failure
154 */
155int av_audio_fifo_drain(AVAudioFifo *af, int nb_samples);
156
157/**
158 * Reset the AVAudioFifo buffer.
159 *
160 * This empties all data in the buffer.
161 *
162 * @param af AVAudioFifo to reset
163 */
165
166/**
167 * Get the current number of samples in the AVAudioFifo available for reading.
168 *
169 * @param af the AVAudioFifo to query
170 * @return number of samples available for reading
171 */
173
174/**
175 * Get the current number of samples in the AVAudioFifo available for writing.
176 *
177 * @param af the AVAudioFifo to query
178 * @return number of samples available for writing
179 */
181
182/**
183 * @}
184 * @}
185 */
186
187#endif /* AVUTIL_AUDIO_FIFO_H */
#define av_warn_unused_result
Definition attributes.h:62
Convenience header that includes libavutil's core.
a very simple circular buffer FIFO implementation
int av_audio_fifo_peek(AVAudioFifo *af, void **data, int nb_samples)
Peek data from an AVAudioFifo.
int av_audio_fifo_write(AVAudioFifo *af, void **data, int nb_samples)
Write data to an AVAudioFifo.
AVAudioFifo * av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels, int nb_samples)
Allocate an AVAudioFifo.
av_warn_unused_result int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples)
Reallocate an AVAudioFifo.
int av_audio_fifo_space(AVAudioFifo *af)
Get the current number of samples in the AVAudioFifo available for writing.
struct AVAudioFifo AVAudioFifo
Context for an Audio FIFO Buffer.
Definition audio_fifo.h:49
void av_audio_fifo_reset(AVAudioFifo *af)
Reset the AVAudioFifo buffer.
int av_audio_fifo_peek_at(AVAudioFifo *af, void **data, int nb_samples, int offset)
Peek data from an AVAudioFifo.
void av_audio_fifo_free(AVAudioFifo *af)
Free an AVAudioFifo.
int av_audio_fifo_size(AVAudioFifo *af)
Get the current number of samples in the AVAudioFifo available for reading.
int av_audio_fifo_read(AVAudioFifo *af, void **data, int nb_samples)
Read data from an AVAudioFifo.
int av_audio_fifo_drain(AVAudioFifo *af, int nb_samples)
Drain data from an AVAudioFifo.
AVSampleFormat
Audio sample formats.
Definition samplefmt.h:58