FFmpeg/libavutil/audio_fifo.h
Ganesh Ajjanagadde dd36749557 avutil/audio_fifo: add av_warn_unused_result
This one should not trigger any warnings, but will be useful for future
robustness.

Strictly speaking, one could check the size after the call by examining
the structure instead of the return value. Such a use case is highly
unusual, and this commit may be easily reverted if there is a legitimate
need of such use.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
2015-10-28 23:05:31 -04:00

171 lines
5.0 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 "avutil.h"
#include "fifo.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 **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(AVAudioFifo *af, void **data, int nb_samples);
/**
* 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 **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 */