 cee308312a
			
		
	
	cee308312a
	
	
	
		
			
			folowing additional options: --enable-w32threads, --arch=i686 (for 32-bit library, workaround for http://trac.ffmpeg.org/ticket/2363)
		
			
				
	
	
		
			148 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * copyright (c) 2005-2012 Michael Niedermayer <michaelni@gmx.at>
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg 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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|  * FFmpeg 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 FFmpeg; 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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| 
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| #ifndef AVUTIL_MATHEMATICS_H
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| #define AVUTIL_MATHEMATICS_H
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| 
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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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| #include "intfloat.h"
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| 
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| #ifndef M_E
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| #define M_E            2.7182818284590452354   /* e */
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| #endif
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| #ifndef M_LN2
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| #define M_LN2          0.69314718055994530942  /* log_e 2 */
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| #endif
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| #ifndef M_LN10
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| #define M_LN10         2.30258509299404568402  /* log_e 10 */
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| #endif
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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 M_PI
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| #define M_PI           3.14159265358979323846  /* pi */
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| #endif
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| #ifndef M_SQRT1_2
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| #define M_SQRT1_2      0.70710678118654752440  /* 1/sqrt(2) */
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| #endif
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| #ifndef M_SQRT2
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| #define M_SQRT2        1.41421356237309504880  /* sqrt(2) */
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| #endif
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| #ifndef NAN
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| #define NAN            av_int2float(0x7fc00000)
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| #endif
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| #ifndef INFINITY
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| #define INFINITY       av_int2float(0x7f800000)
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| #endif
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| 
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| /**
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|  * @addtogroup lavu_math
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|  * @{
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|  */
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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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|     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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| };
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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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| /**
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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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| /**
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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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|  * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is
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|  *         INT64_MIN or INT64_MAX then a is passed through unchanged.
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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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| /**
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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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| /**
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|  * Rescale a 64-bit integer by 2 rational numbers with specified rounding.
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|  *
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|  * @return rescaled value a, or if AV_ROUND_PASS_MINMAX is set and a is
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|  *         INT64_MIN or INT64_MAX then a is passed through unchanged.
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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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| /**
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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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| /**
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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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|  * Rescale a timestamp while preserving known durations.
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|  *
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|  * @param in_ts Input timestamp
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|  * @param in_tb Input timesbase
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|  * @param fs_tb Duration and *last timebase
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|  * @param duration duration till the next call
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|  * @param out_tb Output timesbase
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|  */
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| 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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| 
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| /**
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|  * @}
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|  */
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| 
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| #endif /* AVUTIL_MATHEMATICS_H */
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