1/* 2 * This file is part of FFmpeg. 3 * 4 * FFmpeg is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * FFmpeg is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with FFmpeg; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19/** 20 * @file libavutil/fifo.h 21 * a very simple circular buffer FIFO implementation 22 */ 23 24#ifndef AVUTIL_FIFO_H 25#define AVUTIL_FIFO_H 26 27#include <stdint.h> 28#include "avutil.h" 29#include "common.h" 30 31typedef struct AVFifoBuffer { 32 uint8_t *buffer; 33 uint8_t *rptr, *wptr, *end; 34} AVFifoBuffer; 35 36/** 37 * Initializes an AVFifoBuffer. 38 * @param *f AVFifoBuffer to initialize 39 * @param size of FIFO 40 * @return <0 for failure >=0 otherwise 41 */ 42int av_fifo_init(AVFifoBuffer *f, unsigned int size); 43 44/** 45 * Frees an AVFifoBuffer. 46 * @param *f AVFifoBuffer to free 47 */ 48void av_fifo_free(AVFifoBuffer *f); 49 50/** 51 * Returns the amount of data in bytes in the AVFifoBuffer, that is the 52 * amount of data you can read from it. 53 * @param *f AVFifoBuffer to read from 54 * @return size 55 */ 56int av_fifo_size(AVFifoBuffer *f); 57 58/** 59 * Reads data from an AVFifoBuffer. 60 * @param *f AVFifoBuffer to read from 61 * @param *buf data destination 62 * @param buf_size number of bytes to read 63 */ 64int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size); 65 66/** 67 * Feeds data from an AVFifoBuffer to a user-supplied callback. 68 * @param *f AVFifoBuffer to read from 69 * @param buf_size number of bytes to read 70 * @param *func generic read function 71 * @param *dest data destination 72 */ 73int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest); 74 75#if LIBAVUTIL_VERSION_MAJOR < 50 76/** 77 * Writes data into an AVFifoBuffer. 78 * @param *f AVFifoBuffer to write to 79 * @param *buf data source 80 * @param size data size 81 */ 82attribute_deprecated void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size); 83#endif 84 85/** 86 * Feeds data from a user-supplied callback to an AVFifoBuffer. 87 * @param *f AVFifoBuffer to write to 88 * @param *src data source 89 * @param size number of bytes to write 90 * @param *func generic write function; the first parameter is src, 91 * the second is dest_buf, the third is dest_buf_size. 92 * func must return the number of bytes written to dest_buf, or <= 0 to 93 * indicate no more data available to write. 94 * If func is NULL, src is interpreted as a simple byte array for source data. 95 * @return the number of bytes written to the FIFO 96 */ 97int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int)); 98 99#if LIBAVUTIL_VERSION_MAJOR < 50 100/** 101 * Resizes an AVFifoBuffer. 102 * @param *f AVFifoBuffer to resize 103 * @param size new AVFifoBuffer size in bytes 104 * @see av_fifo_realloc2() 105 */ 106attribute_deprecated void av_fifo_realloc(AVFifoBuffer *f, unsigned int size); 107#endif 108 109/** 110 * Resizes an AVFifoBuffer. 111 * @param *f AVFifoBuffer to resize 112 * @param size new AVFifoBuffer size in bytes 113 * @return <0 for failure, >=0 otherwise 114 */ 115int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size); 116 117/** 118 * Reads and discards the specified amount of data from an AVFifoBuffer. 119 * @param *f AVFifoBuffer to read from 120 * @param size amount of data to read in bytes 121 */ 122void av_fifo_drain(AVFifoBuffer *f, int size); 123 124static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs) 125{ 126 uint8_t *ptr = f->rptr + offs; 127 if (ptr >= f->end) 128 ptr -= f->end - f->buffer; 129 return *ptr; 130} 131#endif /* AVUTIL_FIFO_H */ 132