1 files changed, 12 insertions, 0 deletions
diff --git a/src/libffmpeg/libavcodec/rational.c b/src/libffmpeg/libavcodec/rational.c
index ad085653a..7ccad9e38 100644
--- a/src/libffmpeg/libavcodec/rational.c
+++ b/src/libffmpeg/libavcodec/rational.c
@@ -31,21 +31,33 @@
 #include "avcodec.h"
 #include "rational.h"
 
+/**
+ * returns b*c.
+ */
 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;
 }
 
+/**
+ * returns b/c.
+ */
 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;
 }
 
+/**
+ * returns b+c.
+ */
 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;
 }
 
+/**
+ * returns b-c.
+ */
 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;