1 files changed, 47 insertions, 4 deletions
diff --git a/contrib/ffmpeg/libavutil/rational.h b/contrib/ffmpeg/libavutil/rational.h
index 43fc22114..63c0b150f 100644
--- a/contrib/ffmpeg/libavutil/rational.h
+++ b/contrib/ffmpeg/libavutil/rational.h
@@ -38,7 +38,10 @@ typedef struct AVRational{
 } 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;
@@ -48,24 +51,64 @@ static inline int av_cmp_q(AVRational a, AVRational b){
 }
 
 /**
- * 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