1/* 2 * a very simple circular buffer FIFO implementation 3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard 4 * Copyright (c) 2006 Roman Shaposhnik 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22#include "common.h" 23#include "fifo.h" 24 25int av_fifo_init(AVFifoBuffer *f, unsigned int size) 26{ 27 size= FFMAX(size, size+1); 28 f->wptr = f->rptr = 29 f->buffer = av_malloc(size); 30 f->end = f->buffer + size; 31 if (!f->buffer) 32 return -1; 33 return 0; 34} 35 36void av_fifo_free(AVFifoBuffer *f) 37{ 38 av_free(f->buffer); 39} 40 41int av_fifo_size(AVFifoBuffer *f) 42{ 43 int size = f->wptr - f->rptr; 44 if (size < 0) 45 size += f->end - f->buffer; 46 return size; 47} 48 49int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size) 50{ 51 return av_fifo_generic_read(f, buf_size, NULL, buf); 52} 53 54#if LIBAVUTIL_VERSION_MAJOR < 50 55void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) { 56 av_fifo_realloc2(f, new_size); 57} 58#endif 59 60int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) { 61 unsigned int old_size= f->end - f->buffer; 62 63 if(old_size <= new_size){ 64 int len= av_fifo_size(f); 65 AVFifoBuffer f2; 66 67 if (av_fifo_init(&f2, new_size) < 0) 68 return -1; 69 av_fifo_read(f, f2.buffer, len); 70 f2.wptr += len; 71 av_free(f->buffer); 72 *f= f2; 73 } 74 return 0; 75} 76 77#if LIBAVUTIL_VERSION_MAJOR < 50 78void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size) 79{ 80 av_fifo_generic_write(f, (void *)buf, size, NULL); 81} 82#endif 83 84int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int)) 85{ 86 int total = size; 87 do { 88 int len = FFMIN(f->end - f->wptr, size); 89 if(func) { 90 if(func(src, f->wptr, len) <= 0) 91 break; 92 } else { 93 memcpy(f->wptr, src, len); 94 src = (uint8_t*)src + len; 95 } 96 f->wptr += len; 97 if (f->wptr >= f->end) 98 f->wptr = f->buffer; 99 size -= len; 100 } while (size > 0); 101 return total - size; 102} 103 104 105int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest) 106{ 107 do { 108 int len = FFMIN(f->end - f->rptr, buf_size); 109 if(func) func(dest, f->rptr, len); 110 else{ 111 memcpy(dest, f->rptr, len); 112 dest = (uint8_t*)dest + len; 113 } 114 av_fifo_drain(f, len); 115 buf_size -= len; 116 } while (buf_size > 0); 117 return 0; 118} 119 120/** Discard data from the FIFO. */ 121void av_fifo_drain(AVFifoBuffer *f, int size) 122{ 123 f->rptr += size; 124 if (f->rptr >= f->end) 125 f->rptr -= f->end - f->buffer; 126} 127