Globally rename the header inclusion guard names.
[libav.git] / libavutil / rational.h
CommitLineData
5ff85f1d
MN
1/*
2 * Rational numbers
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 *
b78e7197
DB
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
5ff85f1d
MN
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
5ff85f1d 11 *
b78e7197 12 * FFmpeg is distributed in the hope that it will be useful,
5ff85f1d
MN
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.
16 *
17 * You should have received a copy of the GNU Lesser General Public
b78e7197 18 * License along with FFmpeg; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
5ff85f1d 20 */
115329f1 21
5ff85f1d
MN
22/**
23 * @file rational.h
24 * Rational numbers.
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
98790382
SS
28#ifndef AVUTIL_RATIONAL_H
29#define AVUTIL_RATIONAL_H
5ff85f1d 30
99545457 31#include <stdint.h>
85074d3c 32#include "common.h"
99545457 33
5c07b9e9
MN
34/**
35 * Rational number num/den.
36 */
5ff85f1d 37typedef struct AVRational{
5c07b9e9
MN
38 int num; ///< numerator
39 int den; ///< denominator
5ff85f1d
MN
40} AVRational;
41
5c07b9e9 42/**
1c95ef8b
DB
43 * Compare two rationals.
44 * @param a first rational
45 * @param b second rational
46 * @return 0 if a==b, 1 if a>b and -1 if a<b.
5c07b9e9 47 */
5ff85f1d
MN
48static inline int av_cmp_q(AVRational a, AVRational b){
49 const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
50
5c07b9e9
MN
51 if(tmp) return (tmp>>63)|1;
52 else return 0;
5ff85f1d
MN
53}
54
5c07b9e9 55/**
0b006599 56 * Rational to double conversion.
1c95ef8b
DB
57 * @param a rational to convert
58 * @return (double) a
5c07b9e9 59 */
5ff85f1d
MN
60static inline double av_q2d(AVRational a){
61 return a.num / (double) a.den;
62}
63
c11c2bc2 64/**
1c95ef8b 65 * Reduce a fraction.
804de96a 66 * This is useful for framerate calculations.
1c95ef8b
DB
67 * @param dst_nom destination numerator
68 * @param dst_den destination denominator
69 * @param nom source numerator
70 * @param den source denominator
c11c2bc2
AS
71 * @param max the maximum allowed for dst_nom & dst_den
72 * @return 1 if exact, 0 otherwise
73 */
74int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max);
75
0b006599
DB
76/**
77 * Multiplies two rationals.
78 * @param b first rational.
79 * @param c second rational.
80 * @return b*c.
81 */
85074d3c 82AVRational av_mul_q(AVRational b, AVRational c) av_const;
0b006599
DB
83
84/**
ca9049ef 85 * Divides one rational by another.
0b006599
DB
86 * @param b first rational.
87 * @param c second rational.
88 * @return b/c.
89 */
85074d3c 90AVRational av_div_q(AVRational b, AVRational c) av_const;
0b006599
DB
91
92/**
93 * Adds two rationals.
94 * @param b first rational.
95 * @param c second rational.
96 * @return b+c.
97 */
85074d3c 98AVRational av_add_q(AVRational b, AVRational c) av_const;
0b006599
DB
99
100/**
ca9049ef 101 * Subtracts one rational from another.
0b006599
DB
102 * @param b first rational.
103 * @param c second rational.
71e41994 104 * @return b-c.
0b006599 105 */
85074d3c 106AVRational av_sub_q(AVRational b, AVRational c) av_const;
0b006599
DB
107
108/**
109 * Converts a double precision floating point number to a rational.
110 * @param d double to convert
111 * @param max the maximum allowed numerator and denominator
112 * @return (AVRational) d.
113 */
85074d3c 114AVRational av_d2q(double d, int max) av_const;
5ff85f1d 115
98790382 116#endif /* AVUTIL_RATIONAL_H */