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 module ffmpeg.libavutil.mathematics; 21 import std.stdint; 22 import ffmpeg.libavutil.rational; 23 import ffmpeg.libavutil.intfloat; 24 25 enum M_E = 2.7182818284590452354; /* e */ 26 enum M_LN2 = 0.69314718055994530942; /* log_e 2 */ 27 enum M_LN10 = 2.30258509299404568402; /* log_e 10 */ 28 enum M_LOG2_10 = 3.32192809488736234787; /* log_2 10 */ 29 enum M_PHI = 1.61803398874989484820; /* phi / golden ratio */ 30 enum M_PI = 3.14159265358979323846; /* pi */ 31 enum M_SQRT1_2 = 0.70710678118654752440; /* 1/sqrt(2) */ 32 enum M_SQRT2 = 1.41421356237309504880; /* sqrt(2) */ 33 enum NAN = av_int2float(0x7fc00000); 34 enum INFINITY = av_int2float(0x7f800000); 35 36 37 extern (C): 38 /** 39 * @addtogroup lavu_math 40 * @{ 41 */ 42 enum AVRounding { 43 AV_ROUND_ZERO = 0, 44 AV_ROUND_INF = 1, 45 AV_ROUND_DOWN = 2, 46 AV_ROUND_UP = 3, 47 AV_ROUND_NEAR_INF = 5, 48 } 49 50 /** 51 * Return the greatest common divisor of a and b. 52 * If both a and b are 0 or either or both are <0 then behavior is 53 * undefined. 54 */ 55 int64_t av_gcd(int64_t a, int64_t b); 56 57 /** 58 * Rescale a 64-bit integer with rounding to nearest. 59 * A simple a*b/c isn't possible as it can overflow. 60 */ 61 int64_t av_rescale(int64_t a, int64_t b, int64_t c); 62 63 /** 64 * Rescale a 64-bit integer with specified rounding. 65 * A simple a*b/c isn't possible as it can overflow. 66 */ 67 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, AVRounding); 68 69 /** 70 * Rescale a 64-bit integer by 2 rational numbers. 71 */ 72 int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq); 73 74 /** 75 * Rescale a 64-bit integer by 2 rational numbers with specified rounding. 76 */ 77 int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, 78 AVRounding); 79 80 /** 81 * Compare 2 timestamps each in its own timebases. 82 * The result of the function is undefined if one of the timestamps 83 * is outside the int64_t range when represented in the others timebase. 84 * @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 85 */ 86 int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); 87 88 /** 89 * Compare 2 integers modulo mod. 90 * That is we compare integers a and b for which only the least 91 * significant log2(mod) bits are known. 92 * 93 * @param mod must be a power of 2 94 * @return a negative value if a is smaller than b 95 * a positive value if a is greater than b 96 * 0 if a equals b 97 */ 98 int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); 99 100 101 /** 102 * Rescale a timestamp while preserving known durations. 103 * 104 * @param in_ts Input timestamp 105 * @param in_tb Input timesbase 106 * @param fs_tb Duration and *last timebase 107 * @param duration duration till the next call 108 * @param out_tb Output timesbase 109 */ 110 int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb); 111 112 /** 113 * @} 114 */