2 * A very simple circular buffer FIFO implementation
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 * Copyright (c) 2006 Roman Shaposhnik
6 * This file is part of FFmpeg.
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.
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.
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
25 int av_fifo_init(AVFifoBuffer *f, int size)
27 f->buffer = av_malloc(size);
30 f->end = f->buffer + size;
31 f->wptr = f->rptr = f->buffer;
35 void av_fifo_free(AVFifoBuffer *f)
40 int av_fifo_size(AVFifoBuffer *f)
42 int size = f->wptr - f->rptr;
44 size += f->end - f->buffer;
49 * Get data from the fifo (returns -1 if not enough data).
51 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
53 int size = av_fifo_size(f);
57 while (buf_size > 0) {
58 int len = FFMIN(f->end - f->rptr, buf_size);
59 memcpy(buf, f->rptr, len);
62 if (f->rptr >= f->end)
72 void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
73 unsigned int old_size= f->end - f->buffer;
75 if(old_size < new_size){
76 uint8_t *old= f->buffer;
78 f->buffer= av_realloc(f->buffer, new_size);
80 f->rptr += f->buffer - old;
81 f->wptr += f->buffer - old;
83 if(f->wptr < f->rptr){
84 memmove(f->rptr + new_size - old_size, f->rptr, f->buffer + old_size - f->rptr);
85 f->rptr += new_size - old_size;
87 f->end= f->buffer + new_size;
91 void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
94 int len = FFMIN(f->end - f->wptr, size);
95 memcpy(f->wptr, buf, len);
97 if (f->wptr >= f->end)
105 /* get data from the fifo (return -1 if not enough data) */
106 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
108 int size = av_fifo_size(f);
112 while (buf_size > 0) {
113 int len = FFMIN(f->end - f->rptr, buf_size);
114 func(dest, f->rptr, len);
116 if (f->rptr >= f->end)
123 /* discard data from the fifo */
124 void av_fifo_drain(AVFifoBuffer *f, int size)
127 if (f->rptr >= f->end)
128 f->rptr -= f->end - f->buffer;