1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/*
* copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* 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
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_MATHEMATICS_H
#define AVUTIL_MATHEMATICS_H
#include <stdint.h>
#include <math.h>
#include "attributes.h"
#include "rational.h"
#include "intfloat.h"
#ifndef M_LOG2_10
#define M_LOG2_10 3.32192809488736234787 /* log_2 10 */
#endif
#ifndef M_PHI
#define M_PHI 1.61803398874989484820 /* phi / golden ratio */
#endif
#ifndef NAN
#define NAN av_int2float(0x7fc00000)
#endif
#ifndef INFINITY
#define INFINITY av_int2float(0x7f800000)
#endif
/**
* @addtogroup lavu_math
* @{
*/
enum AVRounding {
AV_ROUND_ZERO = 0, ///< Round toward zero.
AV_ROUND_INF = 1, ///< Round away from zero.
AV_ROUND_DOWN = 2, ///< Round toward -infinity.
AV_ROUND_UP = 3, ///< Round toward +infinity.
AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
};
/**
* Return the greatest common divisor of a and b.
* If both a and b are 0 or either or both are <0 then behavior is
* undefined.
*/
int64_t av_const av_gcd(int64_t a, int64_t b);
/**
* Rescale a 64-bit integer with rounding to nearest.
* A simple a*b/c isn't possible as it can overflow.
*/
int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
/**
* Rescale a 64-bit integer with specified rounding.
* A simple a*b/c isn't possible as it can overflow.
*/
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
/**
* Rescale a 64-bit integer by 2 rational numbers.
*/
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
/**
* Rescale a 64-bit integer by 2 rational numbers with specified rounding.
*/
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
enum AVRounding) av_const;
/**
* Compare 2 timestamps each in its own timebases.
* The result of the function is undefined if one of the timestamps
* is outside the int64_t range when represented in the others timebase.
* @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position
*/
int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b);
/**
* Compare 2 integers modulo mod.
* That is we compare integers a and b for which only the least
* significant log2(mod) bits are known.
*
* @param mod must be a power of 2
* @return a negative value if a is smaller than b
* a positive value if a is greater than b
* 0 if a equals b
*/
int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod);
/**
* @}
*/
#endif /* AVUTIL_MATHEMATICS_H */
|
