3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * @author Michael Niedermayer <michaelni@gmx.at>
33 * Rational number num/den.
35 typedef struct AVRational{
36 int num; ///< numerator
37 int den; ///< denominator
41 * Compare two rationals.
42 * @param a first rational
43 * @param b second rational
44 * @return 0 if a==b, 1 if a>b and -1 if a<b.
46 static inline int av_cmp_q(AVRational a, AVRational b){
47 const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
49 if(tmp) return (tmp>>63)|1;
54 * Rational to double conversion.
55 * @param a rational to convert
58 static inline double av_q2d(AVRational a){
59 return a.num / (double) a.den;
64 * This is useful for framerate calculations.
65 * @param dst_nom destination numerator
66 * @param dst_den destination denominator
67 * @param nom source numerator
68 * @param den source denominator
69 * @param max the maximum allowed for dst_nom & dst_den
70 * @return 1 if exact, 0 otherwise
72 int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max);
75 * Multiplies two rationals.
76 * @param b first rational.
77 * @param c second rational.
80 AVRational av_mul_q(AVRational b, AVRational c);
83 * Divides one rational by another.
84 * @param b first rational.
85 * @param c second rational.
88 AVRational av_div_q(AVRational b, AVRational c);
92 * @param b first rational.
93 * @param c second rational.
96 AVRational av_add_q(AVRational b, AVRational c);
99 * Subtracts one rational from another.
100 * @param b first rational.
101 * @param c second rational.
104 AVRational av_sub_q(AVRational b, AVRational c);
107 * Converts a double precision floating point number to a rational.
108 * @param d double to convert
109 * @param max the maximum allowed numerator and denominator
110 * @return (AVRational) d.
112 AVRational av_d2q(double d, int max);