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/*
* 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 fifo.h
* A very simple circular buffer FIFO implementation.
*/
#ifndef FIFO_H
#define FIFO_H
typedef struct AVFifoBuffer {
uint8_t *buffer;
uint8_t *rptr, *wptr, *end;
} AVFifoBuffer;
/**
* Initializes a FIFO *.
* @param *f FIFO buffer
* @param size of FIFO
* @return <0 for failure >=0 otherwise
*/
int av_fifo_init(AVFifoBuffer *f, int size);
/**
* Frees a FIFO *.
* @param *f FIFO buffer
*/
void av_fifo_free(AVFifoBuffer *f);
/**
* Returns the size of a FIFO *.
* @param *f FIFO buffer
* @return size
*/
int av_fifo_size(AVFifoBuffer *f);
/**
* Reads the data from the FIFO *.
* @param *f FIFO buffer
* @param *buf data destination
* @param buf_size data size
* @return -1 if not enough data
*/
int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size);
/**
* Reads the data from the FIFO *.
* @param *f FIFO buffer
* @param buf_size data size
* @param *func generic read function
* @param *dest data destination
* @return -1 if not enough data
*/
int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest);
/**
* Writes the data in the FIFO *.
* @param *f FIFO buffer
* @param *buf data source
* @param size data size
*/
void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size);
/**
* Resizes the FIFO *.
* @param *f FIFO buffer
* @param size data size
*/
void av_fifo_realloc(AVFifoBuffer *f, unsigned int size);
/**
* Discards the data from the FIFO *.
* @param *f FIFO buffer
* @param size data size
*/
void av_fifo_drain(AVFifoBuffer *f, int size);
/**
* Returns a pointer with circular offset from FIFO's read pointer.
* @param *f FIFO buffer
* @param offs offset
* @return ptr=rptr+offs if rptr+offs<end else rptr+offs -(end-begin)
*/
static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs)
{
uint8_t *ptr = f->rptr + offs;
if (ptr >= f->end)
ptr -= f->end - f->buffer;
return *ptr;
}
#endif /* FIFO_H */
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