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[libav.git] / libavcodec / rational.h
1 /*
2 * Rational numbers
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 */
20
21 /**
22 * @file rational.h
23 * Rational numbers.
24 * @author Michael Niedermayer <michaelni@gmx.at>
25 */
26
27 #ifndef RATIONAL_H
28 #define RATIONAL_H
29
30 /**
31 * Rational number num/den.
32 */
33 typedef struct AVRational{
34 int num; ///< numerator
35 int den; ///< denominator
36 } AVRational;
37
38 /**
39 * returns 0 if a==b, 1 if a>b and -1 if a<b.
40 */
41 static inline int av_cmp_q(AVRational a, AVRational b){
42 const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
43
44 if(tmp) return (tmp>>63)|1;
45 else return 0;
46 }
47
48 /**
49 * converts the given AVRational to a double.
50 */
51 static inline double av_q2d(AVRational a){
52 return a.num / (double) a.den;
53 }
54
55 AVRational av_mul_q(AVRational b, AVRational c);
56 AVRational av_div_q(AVRational b, AVRational c);
57 AVRational av_add_q(AVRational b, AVRational c);
58 AVRational av_sub_q(AVRational b, AVRational c);
59 AVRational av_d2q(double d, int max);
60
61 #endif // RATIONAL_H