3dd27bd1fffbf5597e591d026052eedf4974c044
[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
29 typedef struct AVFifoBuffer {
30 uint8_t *buffer;
31 uint8_t *rptr, *wptr, *end;
32 } AVFifoBuffer;
33
34 /**
35 * Initializes an AVFifoBuffer.
36 * @param *f AVFifoBuffer to initialize
37 * @param size of FIFO
38 * @return <0 for failure >=0 otherwise
39 */
40 int av_fifo_init(AVFifoBuffer *f, int size);
41
42 /**
43 * Frees an AVFifoBuffer.
44 * @param *f AVFifoBuffer to free
45 */
46 void av_fifo_free(AVFifoBuffer *f);
47
48 /**
49 * Returns the amount of data in bytes in the AVFifoBuffer, that is the
50 * amount of data you can read from it.
51 * @param *f AVFifoBuffer to read from
52 * @return size
53 */
54 int av_fifo_size(AVFifoBuffer *f);
55
56 /**
57 * Reads data from an AVFifoBuffer.
58 * @param *f AVFifoBuffer to read from
59 * @param *buf data destination
60 * @param buf_size number of bytes to read
61 */
62 int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size);
63
64 /**
65 * Feeds data from an AVFifoBuffer to a user supplied callback.
66 * @param *f AVFifoBuffer to read from
67 * @param buf_size number of bytes to read
68 * @param *func generic read function
69 * @param *dest data destination
70 */
71 int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest);
72
73 /**
74 * Writes data into an AVFifoBuffer.
75 * @param *f AVFifoBuffer to write to
76 * @param *buf data source
77 * @param size data size
78 */
79 attribute_deprecated void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size);
80
81 /**
82 * Feeds data from a user supplied callback to an AVFifoBuffer.
83 * @param *f AVFifoBuffer to write to
84 * @param *src data source
85 * @param size number of bytes to write
86 * @param *func generic write function. First parameter is src,
87 * second is dest_buf, third is dest_buf_size.
88 * func must return the number of bytes written to dest_buf, or <= 0 to
89 * indicate no more data available to write.
90 * If func is NULL, src is interpreted as a simple byte array for source data.
91 * @return the number of bytes written to the fifo.
92 */
93 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
94
95 /**
96 * Resizes an AVFifoBuffer.
97 * @param *f AVFifoBuffer to resize
98 * @param size new AVFifoBuffer size in bytes
99 */
100 void av_fifo_realloc(AVFifoBuffer *f, unsigned int size);
101
102 /**
103 * Reads and discards the specified amount of data from an AVFifoBuffer.
104 * @param *f AVFifoBuffer to read from
105 * @param size amount of data to read in bytes
106 */
107 void av_fifo_drain(AVFifoBuffer *f, int size);
108
109 static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs)
110 {
111 uint8_t *ptr = f->rptr + offs;
112 if (ptr >= f->end)
113 ptr -= f->end - f->buffer;
114 return *ptr;
115 }
116 #endif /* FFMPEG_FIFO_H */