FFmpeg 7.1.1
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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 "attributes.h"
31#include "samplefmt.h"
32
33/**
34 * @addtogroup lavu_audio
35 * @{
36 *
37 * @defgroup lavu_audiofifo Audio FIFO Buffer
38 * @{
39 */
40
41/**
42 * Context for an Audio FIFO Buffer.
43 *
44 * - Operates at the sample level rather than the byte level.
45 * - Supports multiple channels with either planar or packed sample format.
46 * - Automatic reallocation when writing to a full buffer.
47 */
48typedef struct AVAudioFifo AVAudioFifo;
49
50/**
51 * Free an AVAudioFifo.
52 *
53 * @param af AVAudioFifo to free
54 */
56
57/**
58 * Allocate an AVAudioFifo.
59 *
60 * @param sample_fmt sample format
61 * @param channels number of channels
62 * @param nb_samples initial allocation size, in samples
63 * @return newly allocated AVAudioFifo, or NULL on error
64 */
65AVAudioFifo *av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels,
66 int nb_samples);
67
68/**
69 * Reallocate an AVAudioFifo.
70 *
71 * @param af AVAudioFifo to reallocate
72 * @param nb_samples new allocation size, in samples
73 * @return 0 if OK, or negative AVERROR code on failure
74 */
76int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples);
77
78/**
79 * Write data to an AVAudioFifo.
80 *
81 * The AVAudioFifo will be reallocated automatically if the available space
82 * is less than nb_samples.
83 *
84 * @see enum AVSampleFormat
85 * The documentation for AVSampleFormat describes the data layout.
86 *
87 * @param af AVAudioFifo to write to
88 * @param data audio data plane pointers
89 * @param nb_samples number of samples to write
90 * @return number of samples actually written, or negative AVERROR
91 * code on failure. If successful, the number of samples
92 * actually written will always be nb_samples.
93 */
94int av_audio_fifo_write(AVAudioFifo *af, void * const *data, int nb_samples);
95
96/**
97 * Peek data from an AVAudioFifo.
98 *
99 * @see enum AVSampleFormat
100 * The documentation for AVSampleFormat describes the data layout.
101 *
102 * @param af AVAudioFifo to read from
103 * @param data audio data plane pointers
104 * @param nb_samples number of samples to peek
105 * @return number of samples actually peek, or negative AVERROR code
106 * on failure. The number of samples actually peek will not
107 * be greater than nb_samples, and will only be less than
108 * nb_samples if av_audio_fifo_size is less than nb_samples.
109 */
110int av_audio_fifo_peek(const AVAudioFifo *af, void * const *data, int nb_samples);
111
112/**
113 * Peek data from an AVAudioFifo.
114 *
115 * @see enum AVSampleFormat
116 * The documentation for AVSampleFormat describes the data layout.
117 *
118 * @param af AVAudioFifo to read from
119 * @param data audio data plane pointers
120 * @param nb_samples number of samples to peek
121 * @param offset offset from current read position
122 * @return number of samples actually peek, or negative AVERROR code
123 * on failure. The number of samples actually peek will not
124 * be greater than nb_samples, and will only be less than
125 * nb_samples if av_audio_fifo_size is less than nb_samples.
126 */
127int av_audio_fifo_peek_at(const AVAudioFifo *af, void * const *data,
128 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 * const *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 */
Macro definitions for various function/variable attributes.
#define av_warn_unused_result
Definition attributes.h:62
int av_audio_fifo_peek(const AVAudioFifo *af, void *const *data, int nb_samples)
Peek data from 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_peek_at(const AVAudioFifo *af, void *const *data, int nb_samples, int offset)
Peek data from 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:48
void av_audio_fifo_reset(AVAudioFifo *af)
Reset the AVAudioFifo buffer.
int av_audio_fifo_write(AVAudioFifo *af, void *const *data, int nb_samples)
Write data to an AVAudioFifo.
int av_audio_fifo_read(AVAudioFifo *af, void *const *data, int nb_samples)
Read 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_drain(AVAudioFifo *af, int nb_samples)
Drain data from an AVAudioFifo.
AVSampleFormat
Audio sample formats.
Definition samplefmt.h:55