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/*
* copyright (c) 2005-2012 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"
#include "intfloat.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_PI_2
#define M_PI_2 1.57079632679489661923 /* pi/2 */
#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 av_int2float(0x7fc00000)
#endif
#ifndef INFINITY
#define INFINITY av_int2float(0x7f800000)
#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.
AV_ROUND_PASS_MINMAX = 8192, ///< Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE
};
/**
* Compute the greatest common divisor of a and b.
*
* @return gcd of a and b up to sign; if a >= 0 and b >= 0, return value is >= 0;
* if a == 0 and b == 0, returns 0.
*/
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.
*
* @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is
* INT64_MIN or INT64_MAX then a is passed through unchanged.
*/
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;
/**
* Rescale a 64-bit integer by 2 rational numbers with specified rounding.
*
* @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is
* INT64_MIN or INT64_MAX then a is passed through unchanged.
*/
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
enum AVRounding) 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);
/**
* Rescale a timestamp while preserving known durations.
*
* @param in_ts Input timestamp
* @param in_tb Input timebase
* @param fs_tb Duration and *last timebase
* @param duration duration till the next call
* @param out_tb Output timebase
*/
int64_t av_rescale_delta(AVRational in_tb, int64_t in_ts, AVRational fs_tb, int duration, int64_t *last, AVRational out_tb);
/**
* Add a value to a timestamp.
*
* This function guarantees that when the same value is repeatly added that
* no accumulation of rounding errors occurs.
*
* @param ts Input timestamp
* @param ts_tb Input timestamp timebase
* @param inc value to add to ts
* @param inc_tb inc timebase
*/
int64_t av_add_stable(AVRational ts_tb, int64_t ts, AVRational inc_tb, int64_t inc);
/**
* @}
*/
#endif /* AVUTIL_MATHEMATICS_H */
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