1/*
2 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * 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 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#ifndef AVUTIL_MATHEMATICS_H
22#define AVUTIL_MATHEMATICS_H
23
24#include <stdint.h>
25#include <math.h>
26#include "common.h"
27#include "rational.h"
28
29#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#ifndef M_PI
39#define M_PI           3.14159265358979323846  /* pi */
40#endif
41#ifndef M_SQRT1_2
42#define M_SQRT1_2      0.70710678118654752440  /* 1/sqrt(2) */
43#endif
44
45enum AVRounding {
46    AV_ROUND_ZERO     = 0, ///< Round toward zero.
47    AV_ROUND_INF      = 1, ///< Round away from zero.
48    AV_ROUND_DOWN     = 2, ///< Round toward -infinity.
49    AV_ROUND_UP       = 3, ///< Round toward +infinity.
50    AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
51};
52
53int64_t av_const av_gcd(int64_t a, int64_t b);
54
55/**
56 * Rescales a 64-bit integer with rounding to nearest.
57 * A simple a*b/c isn't possible as it can overflow.
58 */
59int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
60
61/**
62 * Rescales a 64-bit integer with specified rounding.
63 * A simple a*b/c isn't possible as it can overflow.
64 */
65int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
66
67/**
68 * Rescales a 64-bit integer by 2 rational numbers.
69 */
70int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
71
72#endif /* AVUTIL_MATHEMATICS_H */
73