Fix lzo-test linking: -llzo2 should be in ELIBS, not EXTRALIBS.
[libav.git] / libavutil / fifo.h
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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
1faf7dc8 19/**
bad5537e 20 * @file libavutil/fifo.h
89c9ff50 21 * a very simple circular buffer FIFO implementation
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22 */
23
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24#ifndef AVUTIL_FIFO_H
25#define AVUTIL_FIFO_H
f5a478f6 26
99545457 27#include <stdint.h>
af5f434f 28#include "avutil.h"
7c430093 29#include "common.h"
99545457 30
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31typedef struct AVFifoBuffer {
32 uint8_t *buffer;
33 uint8_t *rptr, *wptr, *end;
0a71e78c 34 uint32_t rndx, wndx;
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35} AVFifoBuffer;
36
1faf7dc8 37/**
82ffe191 38 * Initializes an AVFifoBuffer.
1faf7dc8 39 * @param size of FIFO
41dd680d 40 * @return AVFifoBuffer or NULL if mem allocation failure
1faf7dc8 41 */
41dd680d 42AVFifoBuffer *av_fifo_alloc(unsigned int size);
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43
44/**
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45 * Frees an AVFifoBuffer.
46 * @param *f AVFifoBuffer to free
1faf7dc8 47 */
f5a478f6 48void av_fifo_free(AVFifoBuffer *f);
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49
50/**
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51 * Resets the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
52 * @param *f AVFifoBuffer to reset
53 */
54void av_fifo_reset(AVFifoBuffer *f);
55
56/**
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57 * Returns the amount of data in bytes in the AVFifoBuffer, that is the
58 * amount of data you can read from it.
59 * @param *f AVFifoBuffer to read from
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60 * @return size
61 */
f5a478f6 62int av_fifo_size(AVFifoBuffer *f);
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63
64/**
89c9ff50 65 * Feeds data from an AVFifoBuffer to a user-supplied callback.
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66 * @param *f AVFifoBuffer to read from
67 * @param buf_size number of bytes to read
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68 * @param *func generic read function
69 * @param *dest data destination
1faf7dc8 70 */
3898eed8 71int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
1faf7dc8 72
49cec199 73/**
89c9ff50 74 * Feeds data from a user-supplied callback to an AVFifoBuffer.
49cec199 75 * @param *f AVFifoBuffer to write to
95c76e11 76 * @param *src data source
49cec199 77 * @param size number of bytes to write
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78 * @param *func generic write function; the first parameter is src,
79 * the second is dest_buf, the third is dest_buf_size.
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80 * func must return the number of bytes written to dest_buf, or <= 0 to
81 * indicate no more data available to write.
95c76e11 82 * If func is NULL, src is interpreted as a simple byte array for source data.
89c9ff50 83 * @return the number of bytes written to the FIFO
49cec199 84 */
95c76e11 85int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
1faf7dc8 86
1faf7dc8 87/**
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88 * Resizes an AVFifoBuffer.
89 * @param *f AVFifoBuffer to resize
90 * @param size new AVFifoBuffer size in bytes
89c9ff50 91 * @return <0 for failure, >=0 otherwise
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92 */
93int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);
94
95/**
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96 * Reads and discards the specified amount of data from an AVFifoBuffer.
97 * @param *f AVFifoBuffer to read from
98 * @param size amount of data to read in bytes
1faf7dc8 99 */
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100void av_fifo_drain(AVFifoBuffer *f, int size);
101
102static inline uint8_t av_fifo_peek(AVFifoBuffer *f, int offs)
103{
104 uint8_t *ptr = f->rptr + offs;
105 if (ptr >= f->end)
106 ptr -= f->end - f->buffer;
107 return *ptr;
108}
98790382 109#endif /* AVUTIL_FIFO_H */