| 1 | /* |
| 2 | * copyright (c) 2005-2012 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 "attributes.h" |
| 27 | #include "rational.h" |
| 28 | #include "intfloat.h" |
| 29 | |
| 30 | #ifndef M_E |
| 31 | #define M_E 2.7182818284590452354 /* e */ |
| 32 | #endif |
| 33 | #ifndef M_LN2 |
| 34 | #define M_LN2 0.69314718055994530942 /* log_e 2 */ |
| 35 | #endif |
| 36 | #ifndef M_LN10 |
| 37 | #define M_LN10 2.30258509299404568402 /* log_e 10 */ |
| 38 | #endif |
| 39 | #ifndef M_LOG2_10 |
| 40 | #define M_LOG2_10 3.32192809488736234787 /* log_2 10 */ |
| 41 | #endif |
| 42 | #ifndef M_PHI |
| 43 | #define M_PHI 1.61803398874989484820 /* phi / golden ratio */ |
| 44 | #endif |
| 45 | #ifndef M_PI |
| 46 | #define M_PI 3.14159265358979323846 /* pi */ |
| 47 | #endif |
| 48 | #ifndef M_PI_2 |
| 49 | #define M_PI_2 1.57079632679489661923 /* pi/2 */ |
| 50 | #endif |
| 51 | #ifndef M_SQRT1_2 |
| 52 | #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ |
| 53 | #endif |
| 54 | #ifndef M_SQRT2 |
| 55 | #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */ |
| 56 | #endif |
| 57 | #ifndef NAN |
| 58 | #define NAN av_int2float(0x7fc00000) |
| 59 | #endif |
| 60 | #ifndef INFINITY |
| 61 | #define INFINITY av_int2float(0x7f800000) |
| 62 | #endif |
| 63 | |
| 64 | /** |
| 65 | * @addtogroup lavu_math |
| 66 | * @{ |
| 67 | */ |
| 68 | |
| 69 | |
| 70 | enum AVRounding { |
| 71 | AV_ROUND_ZERO = 0, ///< Round toward zero. |
| 72 | AV_ROUND_INF = 1, ///< Round away from zero. |
| 73 | AV_ROUND_DOWN = 2, ///< Round toward -infinity. |
| 74 | AV_ROUND_UP = 3, ///< Round toward +infinity. |
| 75 | AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero. |
| 76 | AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE |
| 77 | }; |
| 78 | |
| 79 | /** |
| 80 | * Return the greatest common divisor of a and b. |
| 81 | * If both a and b are 0 or either or both are <0 then behavior is |
| 82 | * undefined. |
| 83 | */ |
| 84 | int64_t av_const av_gcd(int64_t a, int64_t b); |
| 85 | |
| 86 | /** |
| 87 | * Rescale a 64-bit integer with rounding to nearest. |
| 88 | * A simple a*b/c isn't possible as it can overflow. |
| 89 | */ |
| 90 | int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const; |
| 91 | |
| 92 | /** |
| 93 | * Rescale a 64-bit integer with specified rounding. |
| 94 | * A simple a*b/c isn't possible as it can overflow. |
| 95 | * |
| 96 | * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is |
| 97 | * INT64_MIN or INT64_MAX then a is passed through unchanged. |
| 98 | */ |
| 99 | int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; |
| 100 | |
| 101 | /** |
| 102 | * Rescale a 64-bit integer by 2 rational numbers. |
| 103 | */ |
| 104 | int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; |
| 105 | |
| 106 | /** |
| 107 | * Rescale a 64-bit integer by 2 rational numbers with specified rounding. |
| 108 | * |
| 109 | * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is |
| 110 | * INT64_MIN or INT64_MAX then a is passed through unchanged. |
| 111 | */ |
| 112 | int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, |
| 113 | enum AVRounding) av_const; |
| 114 | |
| 115 | /** |
| 116 | * Compare 2 timestamps each in its own timebases. |
| 117 | * The result of the function is undefined if one of the timestamps |
| 118 | * is outside the int64_t range when represented in the others timebase. |
| 119 | * @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 |
| 120 | */ |
| 121 | int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); |
| 122 | |
| 123 | /** |
| 124 | * Compare 2 integers modulo mod. |
| 125 | * That is we compare integers a and b for which only the least |
| 126 | * significant log2(mod) bits are known. |
| 127 | * |
| 128 | * @param mod must be a power of 2 |
| 129 | * @return a negative value if a is smaller than b |
| 130 | * a positive value if a is greater than b |
| 131 | * 0 if a equals b |
| 132 | */ |
| 133 | int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); |
| 134 | |
| 135 | /** |
| 136 | * Rescale a timestamp while preserving known durations. |
| 137 | * |
| 138 | * @param in_ts Input timestamp |
| 139 | * @param in_tb Input timebase |
| 140 | * @param fs_tb Duration and *last timebase |
| 141 | * @param duration duration till the next call |
| 142 | * @param out_tb Output timebase |
| 143 | */ |
| 144 | int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb); |
| 145 | |
| 146 | /** |
| 147 | * Add a value to a timestamp. |
| 148 | * |
| 149 | * This function guarantees that when the same value is repeatly added that |
| 150 | * no accumulation of rounding errors occurs. |
| 151 | * |
| 152 | * @param ts Input timestamp |
| 153 | * @param ts_tb Input timestamp timebase |
| 154 | * @param inc value to add to ts |
| 155 | * @param inc_tb inc timebase |
| 156 | */ |
| 157 | int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc); |
| 158 | |
| 159 | |
| 160 | /** |
| 161 | * @} |
| 162 | */ |
| 163 | |
| 164 | #endif /* AVUTIL_MATHEMATICS_H */ |