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
)
28 f
->buffer
= av_malloc(size
);
29 f
->end
= f
->buffer
+ size
;
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 return av_fifo_generic_read(f
, buf_size
, NULL
, buf
);
59 void av_fifo_realloc(AVFifoBuffer
*f
, unsigned int new_size
) {
60 unsigned int old_size
= f
->end
- f
->buffer
;
62 if(old_size
< new_size
){
63 int len
= av_fifo_size(f
);
66 av_fifo_init(&f2
, new_size
);
67 av_fifo_read(f
, f2
.buffer
, len
);
74 void av_fifo_write(AVFifoBuffer
*f
, const uint8_t *buf
, int size
)
77 int len
= FFMIN(f
->end
- f
->wptr
, size
);
78 memcpy(f
->wptr
, buf
, len
);
80 if (f
->wptr
>= f
->end
)
88 /** get data from the fifo (return -1 if not enough data) */
89 int av_fifo_generic_read(AVFifoBuffer
*f
, int buf_size
, void (*func
)(void*, void*, int), void* dest
)
91 int size
= av_fifo_size(f
);
96 int len
= FFMIN(f
->end
- f
->rptr
, buf_size
);
97 if(func
) func(dest
, f
->rptr
, len
);
99 memcpy(dest
, f
->rptr
, len
);
100 dest
= (uint8_t*)dest
+ len
;
102 av_fifo_drain(f
, len
);
104 } while (buf_size
> 0);
108 /** discard data from the fifo */
109 void av_fifo_drain(AVFifoBuffer
*f
, int size
)
112 if (f
->rptr
>= f
->end
)
113 f
->rptr
-= f
->end
- f
->buffer
;