Statistics
| Branch: | Revision:

ffmpeg / libavutil / mathematics.h @ 80a07f6e

History | View | Annotate | Download (2.48 KB)

1 04d7f601 Diego Biurrun
/*
2
 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
3
 *
4 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
5
 *
6
 * FFmpeg is free software; you can redistribute it and/or
7 04d7f601 Diego Biurrun
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
9 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
10 04d7f601 Diego Biurrun
 *
11 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
12 04d7f601 Diego Biurrun
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14
 * Lesser General Public License for more details.
15
 *
16
 * You should have received a copy of the GNU Lesser General Public
17 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
18 04d7f601 Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19
 */
20
21 98790382 Stefano Sabatini
#ifndef AVUTIL_MATHEMATICS_H
22
#define AVUTIL_MATHEMATICS_H
23 c11c2bc2 Alexander Strasser
24 6ef29128 Diego Biurrun
#include <stdint.h>
25 d1a12956 Aurelien Jacobs
#include <math.h>
26 b69201a8 Diego Biurrun
#include "common.h"
27 c11c2bc2 Alexander Strasser
#include "rational.h"
28
29 d1a12956 Aurelien Jacobs
#ifndef M_E
30
#define M_E            2.7182818284590452354   /* e */
31
#endif
32
#ifndef M_LN2
33
#define M_LN2          0.69314718055994530942  /* log_e 2 */
34
#endif
35
#ifndef M_LN10
36
#define M_LN10         2.30258509299404568402  /* log_e 10 */
37
#endif
38 5af4f1f3 Aurelien Jacobs
#ifndef M_PI
39
#define M_PI           3.14159265358979323846  /* pi */
40
#endif
41 d1a12956 Aurelien Jacobs
#ifndef M_SQRT1_2
42
#define M_SQRT1_2      0.70710678118654752440  /* 1/sqrt(2) */
43
#endif
44 bd41c06f Måns Rullgård
#ifndef NAN
45
#define NAN            (0.0/0.0)
46
#endif
47
#ifndef INFINITY
48
#define INFINITY       (1.0/0.0)
49
#endif
50 d1a12956 Aurelien Jacobs
51 c11c2bc2 Alexander Strasser
enum AVRounding {
52 89c9ff50 Diego Biurrun
    AV_ROUND_ZERO     = 0, ///< Round toward zero.
53
    AV_ROUND_INF      = 1, ///< Round away from zero.
54
    AV_ROUND_DOWN     = 2, ///< Round toward -infinity.
55
    AV_ROUND_UP       = 3, ///< Round toward +infinity.
56
    AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
57 c11c2bc2 Alexander Strasser
};
58
59 03703cb3 Michael Niedermayer
/**
60
 * Returns the greatest common divisor of a and b.
61 bac24dd2 Michael Niedermayer
 * If both a and b are 0 or either or both are <0 then behavior is
62 03703cb3 Michael Niedermayer
 * undefined.
63
 */
64 9ce6c138 Aurelien Jacobs
int64_t av_const av_gcd(int64_t a, int64_t b);
65
66 c11c2bc2 Alexander Strasser
/**
67 89c9ff50 Diego Biurrun
 * Rescales a 64-bit integer with rounding to nearest.
68
 * A simple a*b/c isn't possible as it can overflow.
69 c11c2bc2 Alexander Strasser
 */
70 85074d3c Zuxy Meng
int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
71 c11c2bc2 Alexander Strasser
72
/**
73 89c9ff50 Diego Biurrun
 * Rescales a 64-bit integer with specified rounding.
74
 * A simple a*b/c isn't possible as it can overflow.
75 c11c2bc2 Alexander Strasser
 */
76 85074d3c Zuxy Meng
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
77 c11c2bc2 Alexander Strasser
78
/**
79 89c9ff50 Diego Biurrun
 * Rescales a 64-bit integer by 2 rational numbers.
80 c11c2bc2 Alexander Strasser
 */
81 85074d3c Zuxy Meng
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
82 c11c2bc2 Alexander Strasser
83 98790382 Stefano Sabatini
#endif /* AVUTIL_MATHEMATICS_H */