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/*
* Rational numbers
* Copyright (c) 2003 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
*/
/**
* @file rational.h
* Rational numbers.
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#ifndef FFMPEG_RATIONAL_H
#define FFMPEG_RATIONAL_H
#include <stdint.h>
/**
* Rational number num/den.
*/
typedef struct AVRational{
int num; ///< numerator
int den; ///< denominator
} AVRational;
/**
* Compare two rationals.
* @param a first rational
* @param b second rational
* @return 0 if a==b, 1 if a>b and -1 if a<b.
*/
static inline int av_cmp_q(AVRational a, AVRational b){
const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
if(tmp) return (tmp>>63)|1;
else return 0;
}
/**
* Rational to double conversion.
* @param a rational to convert
* @return (double) a
*/
static inline double av_q2d(AVRational a){
return a.num / (double) a.den;
}
/**
* Reduce a fraction.
* This is useful for framerate calculations.
* @param dst_nom destination numerator
* @param dst_den destination denominator
* @param nom source numerator
* @param den source denominator
* @param max the maximum allowed for dst_nom & dst_den
* @return 1 if exact, 0 otherwise
*/
int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max);
/**
* Multiplies two rationals.
* @param b first rational.
* @param c second rational.
* @return b*c.
*/
AVRational av_mul_q(AVRational b, AVRational c) av_const;
/**
* Divides one rational by another.
* @param b first rational.
* @param c second rational.
* @return b/c.
*/
AVRational av_div_q(AVRational b, AVRational c) av_const;
/**
* Adds two rationals.
* @param b first rational.
* @param c second rational.
* @return b+c.
*/
AVRational av_add_q(AVRational b, AVRational c) av_const;
/**
* Subtracts one rational from another.
* @param b first rational.
* @param c second rational.
* @return b-c.
*/
AVRational av_sub_q(AVRational b, AVRational c) av_const;
/**
* Converts a double precision floating point number to a rational.
* @param d double to convert
* @param max the maximum allowed numerator and denominator
* @return (AVRational) d.
*/
AVRational av_d2q(double d, int max) av_const;
#endif /* FFMPEG_RATIONAL_H */
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