Libav 0.7.1
libavutil/rational.h
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00001 /*
00002  * rational numbers
00003  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #ifndef AVUTIL_RATIONAL_H
00029 #define AVUTIL_RATIONAL_H
00030 
00031 #include <stdint.h>
00032 #include <limits.h>
00033 #include "attributes.h"
00034 
00038 typedef struct AVRational{
00039     int num; 
00040     int den; 
00041 } AVRational;
00042 
00050 static inline int av_cmp_q(AVRational a, AVRational b){
00051     const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
00052 
00053     if(tmp) return ((tmp ^ a.den ^ b.den)>>63)|1;
00054     else if(b.den && a.den) return 0;
00055     else if(a.num && b.num) return (a.num>>31) - (b.num>>31);
00056     else                    return INT_MIN;
00057 }
00058 
00064 static inline double av_q2d(AVRational a){
00065     return a.num / (double) a.den;
00066 }
00067 
00078 int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max);
00079 
00086 AVRational av_mul_q(AVRational b, AVRational c) av_const;
00087 
00094 AVRational av_div_q(AVRational b, AVRational c) av_const;
00095 
00102 AVRational av_add_q(AVRational b, AVRational c) av_const;
00103 
00110 AVRational av_sub_q(AVRational b, AVRational c) av_const;
00111 
00120 AVRational av_d2q(double d, int max) av_const;
00121 
00126 int av_nearer_q(AVRational q, AVRational q1, AVRational q2);
00127 
00133 int av_find_nearest_q_idx(AVRational q, const AVRational* q_list);
00134 
00135 #endif /* AVUTIL_RATIONAL_H */