Define INFINITIY and NAN in mathematics.h if missing
[libav.git] / libavutil / mathematics.h
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 #ifndef NAN
45 #define NAN (0.0/0.0)
46 #endif
47 #ifndef INFINITY
48 #define INFINITY (1.0/0.0)
49 #endif
50
51 enum AVRounding {
52 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 };
58
59 int64_t av_const av_gcd(int64_t a, int64_t b);
60
61 /**
62 * Rescales a 64-bit integer with rounding to nearest.
63 * A simple a*b/c isn't possible as it can overflow.
64 */
65 int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
66
67 /**
68 * Rescales a 64-bit integer with specified rounding.
69 * A simple a*b/c isn't possible as it can overflow.
70 */
71 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
72
73 /**
74 * Rescales a 64-bit integer by 2 rational numbers.
75 */
76 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
77
78 #endif /* AVUTIL_MATHEMATICS_H */