2a1df34bc39a74881364dc9206204005ecb1d140
[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 INTEGER_H
29 #define INTEGER_H
30
31 #include <stdint.h>
32
33 #define AV_INTEGER_SIZE 8
34
35 typedef struct AVInteger{
36 uint16_t v[AV_INTEGER_SIZE];
37 } AVInteger;
38
39 AVInteger av_add_i(AVInteger a, AVInteger b);
40 AVInteger av_sub_i(AVInteger a, AVInteger b);
41
42 /**
43 * returns the rounded down value of the logarithm of base 2 of the given AVInteger.
44 * this is simply the index of the most significant bit which is 1. Or 0 of all bits are 0
45 */
46 int av_log2_i(AVInteger a);
47 AVInteger av_mul_i(AVInteger a, AVInteger b);
48
49 /**
50 * returns 0 if a==b, 1 if a>b and -1 if a<b.
51 */
52 int av_cmp_i(AVInteger a, AVInteger b);
53
54 /**
55 * bitwise shift.
56 * @param s the number of bits by which the value should be shifted right, may be negative for shifting left
57 */
58 AVInteger av_shr_i(AVInteger a, int s);
59
60 /**
61 * returns a % b.
62 * @param quot a/b will be stored here
63 */
64 AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
65
66 /**
67 * returns a/b.
68 */
69 AVInteger av_div_i(AVInteger a, AVInteger b);
70
71 /**
72 * converts the given int64_t to an AVInteger.
73 */
74 AVInteger av_int2i(int64_t a);
75
76 /**
77 * converts the given AVInteger to an int64_t.
78 * if the AVInteger is too large to fit into an int64_t,
79 * then only the least significant 64bit will be used
80 */
81 int64_t av_i2int(AVInteger a);
82
83 #endif // INTEGER_H