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77 lines
2.1 KiB
77 lines
2.1 KiB
/* |
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* Rational numbers |
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* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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* |
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*/ |
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/** |
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* @file rational.c |
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* Rational numbers |
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* @author Michael Niedermayer <michaelni@gmx.at> |
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*/ |
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//#include <math.h> |
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#include <limits.h> |
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#include "common.h" |
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#include "avcodec.h" |
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#include "rational.h" |
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/** |
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* returns b*c. |
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*/ |
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AVRational av_mul_q(AVRational b, AVRational c){ |
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av_reduce(&b.num, &b.den, b.num * (int64_t)c.num, b.den * (int64_t)c.den, INT_MAX); |
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return b; |
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} |
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/** |
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* returns b/c. |
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*/ |
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AVRational av_div_q(AVRational b, AVRational c){ |
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av_reduce(&b.num, &b.den, b.num * (int64_t)c.den, b.den * (int64_t)c.num, INT_MAX); |
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return b; |
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} |
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/** |
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* returns b+c. |
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*/ |
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AVRational av_add_q(AVRational b, AVRational c){ |
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av_reduce(&b.num, &b.den, b.num * (int64_t)c.den + c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX); |
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return b; |
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} |
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/** |
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* returns b-c. |
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*/ |
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AVRational av_sub_q(AVRational b, AVRational c){ |
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av_reduce(&b.num, &b.den, b.num * (int64_t)c.den - c.num * (int64_t)b.den, b.den * (int64_t)c.den, INT_MAX); |
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return b; |
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} |
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/** |
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* Converts a double precission floating point number to a AVRational. |
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* @param max the maximum allowed numerator and denominator |
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*/ |
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AVRational av_d2q(double d, int max){ |
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AVRational a; |
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int exponent= FFMAX( (int)(log(ABS(d) + 1e-20)/log(2)), 0); |
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int64_t den= 1LL << (61 - exponent); |
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av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max); |
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return a; |
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}
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