* Rational numbers
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * FFmpeg 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
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
} AVRational;
/**
- * returns 0 if a==b, 1 if a>b and -1 if a<b.
+ * Compare two rationals.
+ * @param a first rational
+ * @param b second rational
+ * @return 0 if a==b, 1 if a>b and -1 if a<b.
*/
static inline int av_cmp_q(AVRational a, AVRational b){
const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
}
/**
- * converts the given AVRational to a double.
+ * Rational to double conversion.
+ * @param a rational to convert
+ * @return (double) a
*/
static inline double av_q2d(AVRational a){
return a.num / (double) a.den;
}
/**
- * reduce a fraction.
- * this is usefull for framerate calculations
+ * Reduce a fraction.
+ * This is useful for framerate calculations.
+ * @param dst_nom destination numerator
+ * @param dst_den destination denominator
+ * @param nom source numerator
+ * @param den source denominator
* @param max the maximum allowed for dst_nom & dst_den
* @return 1 if exact, 0 otherwise
*/
int av_reduce(int *dst_nom, int *dst_den, int64_t nom, int64_t den, int64_t max);
+/**
+ * Multiplies two rationals.
+ * @param b first rational.
+ * @param c second rational.
+ * @return b*c.
+ */
AVRational av_mul_q(AVRational b, AVRational c);
+
+/**
+ * Divides one rational by another.
+ * @param b first rational.
+ * @param c second rational.
+ * @return b/c.
+ */
AVRational av_div_q(AVRational b, AVRational c);
+
+/**
+ * Adds two rationals.
+ * @param b first rational.
+ * @param c second rational.
+ * @return b+c.
+ */
AVRational av_add_q(AVRational b, AVRational c);
+
+/**
+ * Subtracts one rational from another.
+ * @param b first rational.
+ * @param c second rational.
+ * returns b-c.
+ */
AVRational av_sub_q(AVRational b, AVRational c);
+
+/**
+ * Converts a double precision floating point number to a rational.
+ * @param d double to convert
+ * @param max the maximum allowed numerator and denominator
+ * @return (AVRational) d.
+ */
AVRational av_d2q(double d, int max);
#endif // RATIONAL_H