www.pudn.com > ffmpeg-Sdk.rar > fifo.h

/* 
 * 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 FFMPEG_FIFO_H 
#define FFMPEG_FIFO_H 
 
#include  
 
typedef struct AVFifoBuffer { 
    uint8_t *buffer; 
    uint8_t *rptr, *wptr, *end; 
} AVFifoBuffer; 
 
/** 
 * Initializes an AVFifoBuffer. 
 * @param *f AVFifoBuffer to initialize 
 * @param size of FIFO 
 * @return <0 for failure >=0 otherwise 
 */ 
int av_fifo_init(AVFifoBuffer *f, int size); 
 
/** 
 * Frees an AVFifoBuffer. 
 * @param *f AVFifoBuffer to free 
 */ 
void av_fifo_free(AVFifoBuffer *f); 
 
/** 
 * Returns the amount of data in bytes in the AVFifoBuffer, that is the 
 * amount of data you can read from it. 
 * @param *f AVFifoBuffer to read from 
 * @return size 
 */ 
int av_fifo_size(AVFifoBuffer *f); 
 
/** 
 * Reads data from an AVFifoBuffer. 
 * @param *f AVFifoBuffer to read from 
 * @param *buf data destination 
 * @param buf_size number of bytes to read 
 */ 
int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size); 
 
/** 
 * Feeds data from an AVFifoBuffer to a user supplied callback. 
 * @param *f AVFifoBuffer to read from 
 * @param buf_size number of bytes to read 
 * @param *func generic read function 
 * @param *dest data destination 
 */ 
int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest); 
 
/** 
 * Writes data into an AVFifoBuffer. 
 * @param *f AVFifoBuffer to write to 
 * @param *buf data source 
 * @param size data size 
 */ 
void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size); 
 
/** 
 * Resizes an AVFifoBuffer. 
 * @param *f AVFifoBuffer to resize 
 * @param size new AVFifoBuffer size in bytes 
 */ 
void av_fifo_realloc(AVFifoBuffer *f, unsigned int size); 
 
/** 
 * Reads and discards the specified amount of data from an AVFifoBuffer. 
 * @param *f AVFifoBuffer to read from 
 * @param size amount of data to read in bytes 
 */ 
void av_fifo_drain(AVFifoBuffer *f, int size); 
 
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 /* FFMPEG_FIFO_H */