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/*
* Rational numbers
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* @file rational.c
* Rational numbers
* @author Michael Niedermayer <michaelni@gmx.at>
*/
//#include <math.h>
#include <limits.h>
#include "common.h"
#include "avcodec.h"
#include "rational.h"
/**
* returns b*c.
*/
AVRational av_mul_q(AVRational b, AVRational c){
av_reduce(&b.num, &b.den, b.num * (int64_t)c.num, b.den * (int64_t)c.den, INT_MAX);
return b;
}
/**
* returns b/c.
*/
AVRational av_div_q(AVRational b, AVRational c){
av_reduce(&b.num, &b.den, b.num * (int64_t)c.den, b.den * (int64_t)c.num, INT_MAX);
return b;
}
/**
* returns b+c.
*/
AVRational av_add_q(AVRational b, AVRational c){
av_reduce(&b.num, &b.den, b.num * (int64_t)c.den + c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX);
return b;
}
/**
* returns b-c.
*/
AVRational av_sub_q(AVRational b, AVRational c){
av_reduce(&b.num, &b.den, b.num * (int64_t)c.den - c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX);
return b;
}
/**
* Converts a double precission floating point number to a AVRational.
* @param max the maximum allowed numerator and denominator
*/
AVRational av_d2q(double d, int max){
AVRational a;
int exponent= FFMAX( (int)(log(ABS(d) + 1e-20)/log(2)), 0);
int64_t den= 1LL << (61 - exponent);
av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max);
return a;
}
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