| 1 | /*
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| 2 | * Rational numbers
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| 3 | * Copyright (c) 2003 Michael Niedermayer <[email protected]>
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| 4 | *
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| 5 | * This library is free software; you can redistribute it and/or
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| 6 | * modify it under the terms of the GNU Lesser General Public
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| 7 | * License as published by the Free Software Foundation; either
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| 8 | * version 2 of the License, or (at your option) any later version.
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| 9 | *
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| 10 | * This library is distributed in the hope that it will be useful,
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| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 13 | * Lesser General Public License for more details.
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| 14 | *
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| 15 | * You should have received a copy of the GNU Lesser General Public
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| 16 | * License along with this library; if not, write to the Free Software
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| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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| 18 | *
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| 19 | */
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| 20 |
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| 21 | /**
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| 22 | * @file rational.h
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| 23 | * Rational numbers.
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| 24 | * @author Michael Niedermayer <[email protected]>
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| 25 | */
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| 26 |
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| 27 | #ifndef RATIONAL_H
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| 28 | #define RATIONAL_H
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| 29 |
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| 30 | /**
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| 31 | * Rational number num/den.
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| 32 | */
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| 33 | typedef struct AVRational{
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| 34 | int num; ///< numerator
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| 35 | int den; ///< denominator
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| 36 | } AVRational;
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| 37 |
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| 38 | /**
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| 39 | * returns 0 if a==b, 1 if a>b and -1 if a<b.
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| 40 | */
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| 41 | static inline int av_cmp_q(AVRational a, AVRational b){
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| 42 | const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
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| 43 |
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| 44 | if(tmp) return (tmp>>63)|1;
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| 45 | else return 0;
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| 46 | }
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| 47 |
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| 48 | /**
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| 49 | * converts the given AVRational to a double.
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| 50 | */
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| 51 | static inline double av_q2d(AVRational a){
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| 52 | return a.num / (double) a.den;
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| 53 | }
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| 54 |
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| 55 | /**
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| 56 | * reduce a fraction.
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| 57 | * this is usefull for framerate calculations
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| 58 | * @param max the maximum allowed for dst_nom & dst_den
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| 59 | * @return 1 if exact, 0 otherwise
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| 60 | */
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| 61 | int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max);
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| 62 |
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| 63 | AVRational av_mul_q(AVRational b, AVRational c);
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| 64 | AVRational av_div_q(AVRational b, AVRational c);
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| 65 | AVRational av_add_q(AVRational b, AVRational c);
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| 66 | AVRational av_sub_q(AVRational b, AVRational c);
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| 67 | AVRational av_d2q(double d, int max);
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| 68 |
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| 69 | #endif // RATIONAL_H
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