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110 lines
3.3 KiB
110 lines
3.3 KiB
/* |
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* copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVUTIL_MATHEMATICS_H |
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#define AVUTIL_MATHEMATICS_H |
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#include <stdint.h> |
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#include <math.h> |
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#include "attributes.h" |
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#include "rational.h" |
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#ifndef M_LOG2_10 |
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#define M_LOG2_10 3.32192809488736234787 /* log_2 10 */ |
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#endif |
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#ifndef M_PHI |
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#define M_PHI 1.61803398874989484820 /* phi / golden ratio */ |
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#endif |
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#ifndef NAN |
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#define NAN (0.0/0.0) |
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#endif |
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#ifndef INFINITY |
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#define INFINITY (1.0/0.0) |
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#endif |
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/** |
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* @addtogroup lavu_math |
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* @{ |
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*/ |
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enum AVRounding { |
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AV_ROUND_ZERO = 0, ///< Round toward zero. |
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AV_ROUND_INF = 1, ///< Round away from zero. |
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AV_ROUND_DOWN = 2, ///< Round toward -infinity. |
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AV_ROUND_UP = 3, ///< Round toward +infinity. |
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AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero. |
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}; |
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/** |
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* Return the greatest common divisor of a and b. |
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* If both a and b are 0 or either or both are <0 then behavior is |
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* undefined. |
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*/ |
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int64_t av_const av_gcd(int64_t a, int64_t b); |
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/** |
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* Rescale a 64-bit integer with rounding to nearest. |
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* A simple a*b/c isn't possible as it can overflow. |
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*/ |
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int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const; |
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/** |
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* Rescale a 64-bit integer with specified rounding. |
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* A simple a*b/c isn't possible as it can overflow. |
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*/ |
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int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const; |
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/** |
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* Rescale a 64-bit integer by 2 rational numbers. |
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*/ |
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int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const; |
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/** |
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* Rescale a 64-bit integer by 2 rational numbers with specified rounding. |
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*/ |
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int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, |
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enum AVRounding) av_const; |
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/** |
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* Compare 2 timestamps each in its own timebases. |
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* The result of the function is undefined if one of the timestamps |
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* is outside the int64_t range when represented in the others timebase. |
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* @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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*/ |
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int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b); |
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/** |
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* Compare 2 integers modulo mod. |
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* That is we compare integers a and b for which only the least |
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* significant log2(mod) bits are known. |
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* |
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* @param mod must be a power of 2 |
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* @return a negative value if a is smaller than b |
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* a positive value if a is greater than b |
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* 0 if a equals b |
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*/ |
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int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod); |
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/** |
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* @} |
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*/ |
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#endif /* AVUTIL_MATHEMATICS_H */
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