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| 4349 | Serge | 1 | /* |
| 2 | * copyright (c) 2005-2012 Michael Niedermayer |
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| 3 | * |
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| 4 | * This file is part of FFmpeg. |
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| 5 | * |
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| 6 | * FFmpeg is free software; you can redistribute it and/or |
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| 7 | * modify it under the terms of the GNU Lesser General Public |
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| 8 | * License as published by the Free Software Foundation; either |
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| 9 | * version 2.1 of the License, or (at your option) any later version. |
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| 10 | * |
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| 11 | * FFmpeg is distributed in the hope that it will be useful, |
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| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | * Lesser General Public License for more details. |
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| 15 | * |
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| 16 | * You should have received a copy of the GNU Lesser General Public |
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| 17 | * License along with FFmpeg; if not, write to the Free Software |
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| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 19 | */ |
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| 20 | |||
| 21 | #ifndef AVUTIL_MATHEMATICS_H |
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| 22 | #define AVUTIL_MATHEMATICS_H |
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| 23 | |||
| 24 | #include |
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| 25 | #include |
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| 26 | #include "attributes.h" |
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| 27 | #include "rational.h" |
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| 28 | #include "intfloat.h" |
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| 29 | |||
| 30 | #ifndef M_E |
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| 31 | #define M_E 2.7182818284590452354 /* e */ |
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| 32 | #endif |
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| 33 | #ifndef M_LN2 |
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| 34 | #define M_LN2 0.69314718055994530942 /* log_e 2 */ |
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| 35 | #endif |
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| 36 | #ifndef M_LN10 |
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| 37 | #define M_LN10 2.30258509299404568402 /* log_e 10 */ |
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| 38 | #endif |
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| 39 | #ifndef M_LOG2_10 |
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| 40 | #define M_LOG2_10 3.32192809488736234787 /* log_2 10 */ |
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| 41 | #endif |
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| 42 | #ifndef M_PHI |
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| 43 | #define M_PHI 1.61803398874989484820 /* phi / golden ratio */ |
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| 44 | #endif |
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| 45 | #ifndef M_PI |
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| 46 | #define M_PI 3.14159265358979323846 /* pi */ |
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| 47 | #endif |
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| 48 | #ifndef M_SQRT1_2 |
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| 49 | #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ |
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| 50 | #endif |
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| 51 | #ifndef M_SQRT2 |
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| 52 | #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */ |
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| 53 | #endif |
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| 54 | #ifndef NAN |
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| 55 | #define NAN av_int2float(0x7fc00000) |
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| 56 | #endif |
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| 57 | #ifndef INFINITY |
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| 58 | #define INFINITY av_int2float(0x7f800000) |
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| 59 | #endif |
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| 60 | |||
| 61 | /** |
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| 62 | * @addtogroup lavu_math |
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| 63 | * @{ |
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| 64 | */ |
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| 65 | |||
| 66 | |||
| 67 | enum AVRounding { |
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| 68 | AV_ROUND_ZERO = 0, ///< Round toward zero. |
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| 69 | AV_ROUND_INF = 1, ///< Round away from zero. |
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| 70 | AV_ROUND_DOWN = 2, ///< Round toward -infinity. |
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| 71 | AV_ROUND_UP = 3, ///< Round toward +infinity. |
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| 72 | AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero. |
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| 73 | AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE |
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| 74 | }; |
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| 75 | |||
| 76 | /** |
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| 77 | * Return the greatest common divisor of a and b. |
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| 78 | * If both a and b are 0 or either or both are <0 then behavior is |
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| 79 | * undefined. |
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| 80 | */ |
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| 81 | int64_t av_const av_gcd(int64_t a, int64_t b); |
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| 82 | |||
| 83 | /** |
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| 84 | * Rescale a 64-bit integer with rounding to nearest. |
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| 85 | * A simple a*b/c isn't possible as it can overflow. |
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| 86 | */ |
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| 87 | int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const; |
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| 88 | |||
| 89 | /** |
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| 90 | * Rescale a 64-bit integer with specified rounding. |
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| 91 | * A simple a*b/c isn't possible as it can overflow. |
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| 92 | * |
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| 93 | * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is |
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| 94 | * INT64_MIN or INT64_MAX then a is passed through unchanged. |
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| 95 | */ |
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| 96 | int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; |
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| 97 | |||
| 98 | /** |
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| 99 | * Rescale a 64-bit integer by 2 rational numbers. |
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| 100 | */ |
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| 101 | int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; |
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| 102 | |||
| 103 | /** |
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| 104 | * Rescale a 64-bit integer by 2 rational numbers with specified rounding. |
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| 105 | * |
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| 106 | * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is |
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| 107 | * INT64_MIN or INT64_MAX then a is passed through unchanged. |
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| 108 | */ |
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| 109 | int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, |
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| 110 | enum AVRounding) av_const; |
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| 111 | |||
| 112 | /** |
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| 113 | * Compare 2 timestamps each in its own timebases. |
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| 114 | * The result of the function is undefined if one of the timestamps |
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| 115 | * is outside the int64_t range when represented in the others timebase. |
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| 116 | * @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 |
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| 117 | */ |
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| 118 | int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); |
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| 119 | |||
| 120 | /** |
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| 121 | * Compare 2 integers modulo mod. |
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| 122 | * That is we compare integers a and b for which only the least |
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| 123 | * significant log2(mod) bits are known. |
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| 124 | * |
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| 125 | * @param mod must be a power of 2 |
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| 126 | * @return a negative value if a is smaller than b |
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| 127 | * a positive value if a is greater than b |
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| 128 | * 0 if a equals b |
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| 129 | */ |
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| 130 | int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); |
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| 131 | |||
| 132 | /** |
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| 133 | * Rescale a timestamp while preserving known durations. |
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| 134 | * |
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| 135 | * @param in_ts Input timestamp |
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| 136 | * @param in_tb Input timesbase |
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| 137 | * @param fs_tb Duration and *last timebase |
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| 138 | * @param duration duration till the next call |
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| 139 | * @param out_tb Output timesbase |
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| 140 | */ |
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| 141 | int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb); |
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| 142 | |||
| 143 | /** |
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| 144 | * @} |
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| 145 | */ |
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| 146 | |||
| 147 | #endif /* AVUTIL_MATHEMATICS_H */ |