b38d5caa3213a9080b80f8e0c1a04bed7845e673
[libav.git] / libavutil / integer.h
1 /*
2 * arbitrary precision integers
3 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file integer.h
24 * arbitrary precision integers
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
28 #ifndef FFMPEG_INTEGER_H
29 #define FFMPEG_INTEGER_H
30
31 #include <stdint.h>
32 #include "common.h"
33
34 #define AV_INTEGER_SIZE 8
35
36 typedef struct AVInteger{
37 uint16_t v[AV_INTEGER_SIZE];
38 } AVInteger;
39
40 AVInteger av_add_i(AVInteger a, AVInteger b) av_const;
41 AVInteger av_sub_i(AVInteger a, AVInteger b) av_const;
42
43 /**
44 * returns the rounded down value of the logarithm of base 2 of the given AVInteger.
45 * this is simply the index of the most significant bit which is 1. Or 0 of all bits are 0
46 */
47 int av_log2_i(AVInteger a) av_const;
48 AVInteger av_mul_i(AVInteger a, AVInteger b) av_const;
49
50 /**
51 * returns 0 if a==b, 1 if a>b and -1 if a<b.
52 */
53 int av_cmp_i(AVInteger a, AVInteger b) av_const;
54
55 /**
56 * bitwise shift.
57 * @param s the number of bits by which the value should be shifted right, may be negative for shifting left
58 */
59 AVInteger av_shr_i(AVInteger a, int s) av_const;
60
61 /**
62 * returns a % b.
63 * @param quot a/b will be stored here
64 */
65 AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
66
67 /**
68 * returns a/b.
69 */
70 AVInteger av_div_i(AVInteger a, AVInteger b) av_const;
71
72 /**
73 * converts the given int64_t to an AVInteger.
74 */
75 AVInteger av_int2i(int64_t a) av_const;
76
77 /**
78 * converts the given AVInteger to an int64_t.
79 * if the AVInteger is too large to fit into an int64_t,
80 * then only the least significant 64bit will be used
81 */
82 int64_t av_i2int(AVInteger a) av_const;
83
84 #endif /* FFMPEG_INTEGER_H */