/* * 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 RATIONAL_H #define RATIONAL_H /** * Rational number num/den. */ typedef struct AVRational{ int num; ///< numerator int den; ///< denominator } AVRational; /** * returns 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; } /** * converts the given AVRational to a double. */ static inline double av_q2d(AVRational a){ return a.num / (double) a.den; } /** * reduce a fraction. * this is usefull for framerate calculations * @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); AVRational av_mul_q(AVRational b, AVRational c); AVRational av_div_q(AVRational b, AVRational c); AVRational av_add_q(AVRational b, AVRational c); AVRational av_sub_q(AVRational b, AVRational c); AVRational av_d2q(double d, int max); #endif // RATIONAL_H