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- /*
- * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
- #ifndef AVUTIL_MATHEMATICS_H
- #define AVUTIL_MATHEMATICS_H
- #include <stdint.h>
- #include <math.h>
- #include "attributes.h"
- #include "rational.h"
- #ifndef M_E
- #define M_E 2.7182818284590452354 /* e */
- #endif
- #ifndef M_LN2
- #define M_LN2 0.69314718055994530942 /* log_e 2 */
- #endif
- #ifndef M_LN10
- #define M_LN10 2.30258509299404568402 /* log_e 10 */
- #endif
- #ifndef M_LOG2_10
- #define M_LOG2_10 3.32192809488736234787 /* log_2 10 */
- #endif
- #ifndef M_PHI
- #define M_PHI 1.61803398874989484820 /* phi / golden ratio */
- #endif
- #ifndef M_PI
- #define M_PI 3.14159265358979323846 /* pi */
- #endif
- #ifndef M_SQRT1_2
- #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
- #endif
- #ifndef M_SQRT2
- #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
- #endif
- #ifndef NAN
- #define NAN (0.0/0.0)
- #endif
- #ifndef INFINITY
- #define INFINITY (1.0/0.0)
- #endif
- /**
- * @addtogroup lavu_math
- * @{
- */
- enum AVRounding {
- AV_ROUND_ZERO = 0, ///< Round toward zero.
- AV_ROUND_INF = 1, ///< Round away from zero.
- AV_ROUND_DOWN = 2, ///< Round toward -infinity.
- AV_ROUND_UP = 3, ///< Round toward +infinity.
- AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
- };
- /**
- * Return the greatest common divisor of a and b.
- * If both a and b are 0 or either or both are <0 then behavior is
- * undefined.
- */
- int64_t av_const av_gcd(int64_t a, int64_t b);
- /**
- * Rescale a 64-bit integer with rounding to nearest.
- * A simple a*b/c isn't possible as it can overflow.
- */
- int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;
- /**
- * Rescale a 64-bit integer with specified rounding.
- * A simple a*b/c isn't possible as it can overflow.
- */
- int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;
- /**
- * Rescale a 64-bit integer by 2 rational numbers.
- */
- int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
- /**
- * Compare 2 timestamps each in its own timebases.
- * The result of the function is undefined if one of the timestamps
- * is outside the int64_t range when represented in the others timebase.
- * @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
- */
- int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b);
- /**
- * Compare 2 integers modulo mod.
- * That is we compare integers a and b for which only the least
- * significant log2(mod) bits are known.
- *
- * @param mod must be a power of 2
- * @return a negative value if a is smaller than b
- * a positive value if a is greater than b
- * 0 if a equals b
- */
- int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod);
- /**
- * @}
- */
- #endif /* AVUTIL_MATHEMATICS_H */
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