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Diffstat (limited to 'libavcodec/rational.c')
-rw-r--r-- | libavcodec/rational.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libavcodec/rational.c b/libavcodec/rational.c new file mode 100644 index 0000000000..f2a579abca --- /dev/null +++ b/libavcodec/rational.c @@ -0,0 +1,61 @@ +/* + * Rational numbers + * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/** + * @file rational.c + * Rational numbers + * @author Michael Niedermayer <michaelni@gmx.at> + */ + +//#include <math.h> +#include <limits.h> + +#include "common.h" +#include "avcodec.h" +#include "rational.h" + +AVRational av_mul_q(AVRational b, AVRational c){ + av_reduce(&b.num, &b.den, b.num * (int64_t)c.num, b.den * (int64_t)c.den, INT_MAX); + return b; +} + +AVRational av_div_q(AVRational b, AVRational c){ + av_reduce(&b.num, &b.den, b.num * (int64_t)c.den, b.den * (int64_t)c.num, INT_MAX); + return b; +} + +AVRational av_add_q(AVRational b, AVRational c){ + 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); + return b; +} + +AVRational av_sub_q(AVRational b, AVRational c){ + 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); + return b; +} + +AVRational av_d2q(double d, int max){ + AVRational a; + int exponent= FFMAX( (int)log2(ABS(d) + 1e-20), 0); + int64_t den= 1LL << (61 - exponent); + av_reduce(&a.num, &a.den, (int64_t)(d * den + 0.5), den, max); + + return a; +} |