*/
/**
- * @file rational.h
+ * @file
* rational numbers
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#define AVUTIL_RATIONAL_H
#include <stdint.h>
-#include "common.h"
+#include <limits.h>
+#include "attributes.h"
/**
* rational number numerator/denominator
} AVRational;
/**
- * Compares two rationals.
+ * 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
+ * @return 0 if a==b, 1 if a>b, -1 if a<b, and INT_MIN if one of the
+ * values is of the form 0/0
*/
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;
- if(tmp) return (tmp>>63)|1;
- else return 0;
+ if(tmp) return ((tmp ^ a.den ^ b.den)>>63)|1;
+ else if(b.den && a.den) return 0;
+ else if(a.num && b.num) return (a.num>>31) - (b.num>>31);
+ else return INT_MIN;
}
/**
- * Converts rational to double.
+ * Convert rational to double.
* @param a rational to convert
* @return (double) a
*/
}
/**
- * Reduces a fraction.
+ * Reduce a fraction.
* This is useful for framerate calculations.
- * @param dst_nom destination numerator
+ * @param dst_num destination numerator
* @param dst_den destination denominator
- * @param nom source numerator
+ * @param num source numerator
* @param den source denominator
- * @param max the maximum allowed for dst_nom & dst_den
+ * @param max the maximum allowed for dst_num & 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);
+int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max);
/**
- * Multiplies two rationals.
+ * Multiply two rationals.
* @param b first rational
* @param c second rational
* @return b*c
AVRational av_mul_q(AVRational b, AVRational c) av_const;
/**
- * Divides one rational by another.
+ * Divide one rational by another.
* @param b first rational
* @param c second rational
* @return b/c
AVRational av_div_q(AVRational b, AVRational c) av_const;
/**
- * Adds two rationals.
+ * Add two rationals.
* @param b first rational
* @param c second rational
* @return b+c
AVRational av_add_q(AVRational b, AVRational c) av_const;
/**
- * Subtracts one rational from another.
+ * Subtract one rational from another.
* @param b first rational
* @param c second rational
* @return b-c
AVRational av_sub_q(AVRational b, AVRational c) av_const;
/**
- * Converts a double precision floating point number to a rational.
+ * Convert a double precision floating point number to a rational.
+ * inf is expressed as {1,0} or {-1,0} depending on the sign.
+ *
* @param d double to convert
* @param max the maximum allowed numerator and denominator
* @return (AVRational) d
AVRational av_d2q(double d, int max) av_const;
/**
- * @return 1 if \q1 is nearer to \p q than \p q2, -1 if \p q2 is nearer
- * than \p q1, 0 if they have the same distance.
+ * @return 1 if q1 is nearer to q than q2, -1 if q2 is nearer
+ * than q1, 0 if they have the same distance.
*/
int av_nearer_q(AVRational q, AVRational q1, AVRational q2);
/**
- * Finds the nearest value in \p q_list to \p q.
+ * Find the nearest value in q_list to q.
* @param q_list an array of rationals terminated by {0, 0}
* @return the index of the nearest value found in the array
*/