Globally rename the header inclusion guard names.
[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 "rational.h"
27
28 #ifndef M_E
29 #define M_E 2.7182818284590452354 /* e */
30 #endif
31 #ifndef M_LN2
32 #define M_LN2 0.69314718055994530942 /* log_e 2 */
33 #endif
34 #ifndef M_LN10
35 #define M_LN10 2.30258509299404568402 /* log_e 10 */
36 #endif
37 #ifndef M_PI
38 #define M_PI 3.14159265358979323846 /* pi */
39 #endif
40 #ifndef M_SQRT1_2
41 #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
42 #endif
43
44 enum AVRounding {
45 AV_ROUND_ZERO = 0, ///< round toward zero
46 AV_ROUND_INF = 1, ///< round away from zero
47 AV_ROUND_DOWN = 2, ///< round toward -infinity
48 AV_ROUND_UP = 3, ///< round toward +infinity
49 AV_ROUND_NEAR_INF = 5, ///< round to nearest and halfway cases away from zero
50 };
51
52 /**
53 * rescale a 64bit integer with rounding to nearest.
54 * a simple a*b/c isn't possible as it can overflow
55 */
56 int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
57
58 /**
59 * rescale a 64bit integer with specified rounding.
60 * a simple a*b/c isn't possible as it can overflow
61 */
62 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
63
64 /**
65 * rescale a 64bit integer by 2 rational numbers.
66 */
67 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
68
69 #endif /* AVUTIL_MATHEMATICS_H */