integer.h 2.23 KB
Newer Older
1 2 3 4
/*
 * arbitrary precision integers
 * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
 *
5 6 7
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
8 9
 * modify it under the terms of the GNU Lesser General Public
 * 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 14 15 16 17
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * 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 24 25 26
/**
 * @file integer.h
 * arbitrary precision integers
 * @author Michael Niedermayer <michaelni@gmx.at>
 */
27

28 29
#ifndef FFMPEG_INTEGER_H
#define FFMPEG_INTEGER_H
30

31 32
#include <stdint.h>

33 34 35
#define AV_INTEGER_SIZE 8

typedef struct AVInteger{
36
    uint16_t v[AV_INTEGER_SIZE];
37 38 39 40
} AVInteger;

AVInteger av_add_i(AVInteger a, AVInteger b);
AVInteger av_sub_i(AVInteger a, AVInteger b);
41 42 43 44 45

/**
 * returns the rounded down value of the logarithm of base 2 of the given AVInteger.
 * 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);
AVInteger av_mul_i(AVInteger a, AVInteger b);
48 49 50 51

/**
 * returns 0 if a==b, 1 if a>b and -1 if a<b.
 */
52
int av_cmp_i(AVInteger a, AVInteger b);
53 54 55 56 57

/**
 * bitwise shift.
 * @param s the number of bits by which the value should be shifted right, may be negative for shifting left
 */
58
AVInteger av_shr_i(AVInteger a, int s);
59 60 61 62 63

/**
 * returns a % b.
 * @param quot a/b will be stored here
 */
64
AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b);
65 66 67 68

/**
 * returns a/b.
 */
69
AVInteger av_div_i(AVInteger a, AVInteger b);
70 71 72 73

/**
 * converts the given int64_t to an AVInteger.
 */
74
AVInteger av_int2i(int64_t a);
75 76 77 78 79 80

/**
 * converts the given AVInteger to an int64_t.
 * if the AVInteger is too large to fit into an int64_t,
 * then only the least significant 64bit will be used
 */
81 82
int64_t av_i2int(AVInteger a);

83
#endif /* FFMPEG_INTEGER_H */