mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
a1245d5ca1
Some compilers, MSVC among them, don't recognize the divisions by zero as meaning infinity/nan. These macros should, according to the standard, expand to constant expressions, but this shouldn't matter for our usage. Signed-off-by: Martin Storsjö <martin@martin.st>
112 lines
3.3 KiB
C
112 lines
3.3 KiB
C
/*
|
|
* copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; 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_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 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.
|
|
};
|
|
|
|
/**
|
|
* 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;
|
|
|
|
/**
|
|
* Rescale a 64-bit integer by 2 rational numbers with specified rounding.
|
|
*/
|
|
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);
|
|
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
#endif /* AVUTIL_MATHEMATICS_H */
|