FFmpeg
integer.h
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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
24  * arbitrary precision integers
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27 
28 #ifndef AVUTIL_INTEGER_H
29 #define AVUTIL_INTEGER_H
30 
31 #include <stdint.h>
32 #include "attributes.h"
33 
34 #define AV_INTEGER_SIZE 8
35 
36 typedef struct AVInteger{
37  uint16_t v[AV_INTEGER_SIZE];
38 } AVInteger;
39 
42 
43 /**
44  * Return the rounded-down value of the base 2 logarithm of the given
45  * AVInteger. This is simply the index of the most significant bit
46  * which is 1, or 0 if all bits are 0.
47  */
50 
51 /**
52  * Return 0 if a==b, 1 if a>b and -1 if a<b.
53  */
55 
56 /**
57  * bitwise shift
58  * @param s the number of bits by which the value should be shifted right,
59  may be negative for shifting left
60  */
62 
63 /**
64  * Return a % b.
65  * @param quot a/b will be stored here.
66  */
68 
69 /**
70  * Return a/b.
71  */
73 
74 /**
75  * Convert the given int64_t to an AVInteger.
76  */
77 AVInteger av_int2i(int64_t a) av_const;
78 
79 /**
80  * Convert the given AVInteger to an int64_t.
81  * If the AVInteger is too large to fit into an int64_t,
82  * then only the least significant 64 bits will be used.
83  */
84 int64_t av_i2int(AVInteger a) av_const;
85 
86 #endif /* AVUTIL_INTEGER_H */
av_add_i
AVInteger av_add_i(AVInteger a, AVInteger b) av_const
Definition: integer.c:36
av_int2i
AVInteger av_int2i(int64_t a) av_const
Convert the given int64_t to an AVInteger.
Definition: integer.c:149
av_const
#define av_const
Definition: attributes.h:84
b
#define b
Definition: input.c:34
av_cmp_i
int av_cmp_i(AVInteger a, AVInteger b) av_const
Return 0 if a==b, 1 if a>b and -1 if a<b.
Definition: integer.c:87
av_i2int
int64_t av_i2int(AVInteger a) av_const
Convert the given AVInteger to an int64_t.
Definition: integer.c:160
s
#define s(width, name)
Definition: cbs_vp9.c:256
av_mul_i
AVInteger av_mul_i(AVInteger a, AVInteger b) av_const
Definition: integer.c:66
av_div_i
AVInteger av_div_i(AVInteger a, AVInteger b) av_const
Return a/b.
Definition: integer.c:143
av_shr_i
AVInteger av_shr_i(AVInteger a, int s) av_const
bitwise shift
Definition: integer.c:99
av_mod_i
AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b)
Return a % b.
Definition: integer.c:113
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
attributes.h
AVInteger::v
uint16_t v[AV_INTEGER_SIZE]
Definition: integer.h:37
AVInteger
Definition: integer.h:36
av_log2_i
int av_log2_i(AVInteger a) av_const
Return the rounded-down value of the base 2 logarithm of the given AVInteger.
Definition: integer.c:56
av_sub_i
AVInteger av_sub_i(AVInteger a, AVInteger b) av_const
Definition: integer.c:46
AV_INTEGER_SIZE
#define AV_INTEGER_SIZE
Definition: integer.h:34