f5fb144211ac261b8567572f6a8b1c9cd964b09c
[libav.git] / libavutil / fifo.h
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 fifo.h
21 * A very simple circular buffer FIFO implementation.
22 */
23
24 #ifndef FFMPEG_FIFO_H
25 #define FFMPEG_FIFO_H
26
27 #include <stdint.h>
28 #include "common.h"
29
30 typedef struct AVFifoBuffer {
31 uint8_t *buffer;
32 uint8_t *rptr, *wptr, *end;
33 } AVFifoBuffer;
34
35 /**
36 * Initializes an AVFifoBuffer.
37 * @param *f AVFifoBuffer to initialize
38 * @param size of FIFO
39 * @return <0 for failure >=0 otherwise
40 */
41 int av_fifo_init(AVFifoBuffer *f, int size);
42
43 /**
44 * Frees an AVFifoBuffer.
45 * @param *f AVFifoBuffer to free
46 */
47 void av_fifo_free(AVFifoBuffer *f);
48
49 /**
50 * Returns the amount of data in bytes in the AVFifoBuffer, that is the
51 * amount of data you can read from it.
52 * @param *f AVFifoBuffer to read from
53 * @return size
54 */
55 int av_fifo_size(AVFifoBuffer *f);
56
57 /**
58 * Reads data from an AVFifoBuffer.
59 * @param *f AVFifoBuffer to read from
60 * @param *buf data destination
61 * @param buf_size number of bytes to read
62 */
63 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size);
64
65 /**
66 * Feeds data from an AVFifoBuffer to a user supplied callback.
67 * @param *f AVFifoBuffer to read from
68 * @param buf_size number of bytes to read
69 * @param *func generic read function
70 * @param *dest data destination
71 */
72 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest);
73
74 /**
75 * Writes data into an AVFifoBuffer.
76 * @param *f AVFifoBuffer to write to
77 * @param *buf data source
78 * @param size data size
79 */
80 attribute_deprecated void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size);
81
82 /**
83 * Feeds data from a user supplied callback to an AVFifoBuffer.
84 * @param *f AVFifoBuffer to write to
85 * @param *src data source
86 * @param size number of bytes to write
87 * @param *func generic write function. First parameter is src,
88 * second is dest_buf, third is dest_buf_size.
89 * func must return the number of bytes written to dest_buf, or <= 0 to
90 * indicate no more data available to write.
91 * If func is NULL, src is interpreted as a simple byte array for source data.
92 * @return the number of bytes written to the fifo.
93 */
94 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
95
96 /**
97 * Resizes an AVFifoBuffer.
98 * @param *f AVFifoBuffer to resize
99 * @param size new AVFifoBuffer size in bytes
100 */
101 void av_fifo_realloc(AVFifoBuffer *f, unsigned int size);
102
103 /**
104 * Reads and discards the specified amount of data from an AVFifoBuffer.
105 * @param *f AVFifoBuffer to read from
106 * @param size amount of data to read in bytes
107 */
108 void av_fifo_drain(AVFifoBuffer *f, int size);
109
110 static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs)
111 {
112 uint8_t *ptr = f->rptr + offs;
113 if (ptr >= f->end)
114 ptr -= f->end - f->buffer;
115 return *ptr;
116 }
117 #endif /* FFMPEG_FIFO_H */