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 */ 56void av_audio_fifo_free(AVAudioFifo *af); 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 */ 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 **data, int nb_samples); 95 96/** 97 * Read 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 read 105 * @return number of samples actually read, or negative AVERROR code 106 * on failure. The number of samples actually read 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_read(AVAudioFifo *af, void **data, int nb_samples); 111 112/** 113 * Drain data from an AVAudioFifo. 114 * 115 * Removes the data without reading it. 116 * 117 * @param af AVAudioFifo to drain 118 * @param nb_samples number of samples to drain 119 * @return 0 if OK, or negative AVERROR code on failure 120 */ 121int av_audio_fifo_drain(AVAudioFifo *af, int nb_samples); 122 123/** 124 * Reset the AVAudioFifo buffer. 125 * 126 * This empties all data in the buffer. 127 * 128 * @param af AVAudioFifo to reset 129 */ 130void av_audio_fifo_reset(AVAudioFifo *af); 131 132/** 133 * Get the current number of samples in the AVAudioFifo available for reading. 134 * 135 * @param af the AVAudioFifo to query 136 * @return number of samples available for reading 137 */ 138int av_audio_fifo_size(AVAudioFifo *af); 139 140/** 141 * Get the current number of samples in the AVAudioFifo available for writing. 142 * 143 * @param af the AVAudioFifo to query 144 * @return number of samples available for writing 145 */ 146int av_audio_fifo_space(AVAudioFifo *af); 147 148/** 149 * @} 150 * @} 151 */ 152 153#endif /* AVUTIL_AUDIO_FIFO_H */ 154