ffmpeg/libavutil/audio_fifo.h

188 lines
5.8 KiB
C

/*
* Audio FIFO
* Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Audio FIFO Buffer
*/
#ifndef AVUTIL_AUDIO_FIFO_H
#define AVUTIL_AUDIO_FIFO_H
#include "attributes.h"
#include "samplefmt.h"
/**
* @addtogroup lavu_audio
* @{
*
* @defgroup lavu_audiofifo Audio FIFO Buffer
* @{
*/
/**
* Context for an Audio FIFO Buffer.
*
* - Operates at the sample level rather than the byte level.
* - Supports multiple channels with either planar or packed sample format.
* - Automatic reallocation when writing to a full buffer.
*/
typedef struct AVAudioFifo AVAudioFifo;
/**
* Free an AVAudioFifo.
*
* @param af AVAudioFifo to free
*/
void av_audio_fifo_free(AVAudioFifo *af);
/**
* Allocate an AVAudioFifo.
*
* @param sample_fmt sample format
* @param channels number of channels
* @param nb_samples initial allocation size, in samples
* @return newly allocated AVAudioFifo, or NULL on error
*/
AVAudioFifo *av_audio_fifo_alloc(enum AVSampleFormat sample_fmt, int channels,
int nb_samples);
/**
* Reallocate an AVAudioFifo.
*
* @param af AVAudioFifo to reallocate
* @param nb_samples new allocation size, in samples
* @return 0 if OK, or negative AVERROR code on failure
*/
av_warn_unused_result
int av_audio_fifo_realloc(AVAudioFifo *af, int nb_samples);
/**
* Write data to an AVAudioFifo.
*
* The AVAudioFifo will be reallocated automatically if the available space
* is less than nb_samples.
*
* @see enum AVSampleFormat
* The documentation for AVSampleFormat describes the data layout.
*
* @param af AVAudioFifo to write to
* @param data audio data plane pointers
* @param nb_samples number of samples to write
* @return number of samples actually written, or negative AVERROR
* code on failure. If successful, the number of samples
* actually written will always be nb_samples.
*/
int av_audio_fifo_write(AVAudioFifo *af, void * const *data, int nb_samples);
/**
* Peek data from an AVAudioFifo.
*
* @see enum AVSampleFormat
* The documentation for AVSampleFormat describes the data layout.
*
* @param af AVAudioFifo to read from
* @param data audio data plane pointers
* @param nb_samples number of samples to peek
* @return number of samples actually peek, or negative AVERROR code
* on failure. The number of samples actually peek will not
* be greater than nb_samples, and will only be less than
* nb_samples if av_audio_fifo_size is less than nb_samples.
*/
int av_audio_fifo_peek(const AVAudioFifo *af, void * const *data, int nb_samples);
/**
* Peek data from an AVAudioFifo.
*
* @see enum AVSampleFormat
* The documentation for AVSampleFormat describes the data layout.
*
* @param af AVAudioFifo to read from
* @param data audio data plane pointers
* @param nb_samples number of samples to peek
* @param offset offset from current read position
* @return number of samples actually peek, or negative AVERROR code
* on failure. The number of samples actually peek will not
* be greater than nb_samples, and will only be less than
* nb_samples if av_audio_fifo_size is less than nb_samples.
*/
int av_audio_fifo_peek_at(const AVAudioFifo *af, void * const *data,
int nb_samples, int offset);
/**
* Read data from an AVAudioFifo.
*
* @see enum AVSampleFormat
* The documentation for AVSampleFormat describes the data layout.
*
* @param af AVAudioFifo to read from
* @param data audio data plane pointers
* @param nb_samples number of samples to read
* @return number of samples actually read, or negative AVERROR code
* on failure. The number of samples actually read will not
* be greater than nb_samples, and will only be less than
* nb_samples if av_audio_fifo_size is less than nb_samples.
*/
int av_audio_fifo_read(AVAudioFifo *af, void * const *data, int nb_samples);
/**
* Drain data from an AVAudioFifo.
*
* Removes the data without reading it.
*
* @param af AVAudioFifo to drain
* @param nb_samples number of samples to drain
* @return 0 if OK, or negative AVERROR code on failure
*/
int av_audio_fifo_drain(AVAudioFifo *af, int nb_samples);
/**
* Reset the AVAudioFifo buffer.
*
* This empties all data in the buffer.
*
* @param af AVAudioFifo to reset
*/
void av_audio_fifo_reset(AVAudioFifo *af);
/**
* Get the current number of samples in the AVAudioFifo available for reading.
*
* @param af the AVAudioFifo to query
* @return number of samples available for reading
*/
int av_audio_fifo_size(AVAudioFifo *af);
/**
* Get the current number of samples in the AVAudioFifo available for writing.
*
* @param af the AVAudioFifo to query
* @return number of samples available for writing
*/
int av_audio_fifo_space(AVAudioFifo *af);
/**
* @}
* @}
*/
#endif /* AVUTIL_AUDIO_FIFO_H */