avformat: keep r_frame_rate

This field is used and nothing equivalent exists

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/utils.c

@@ -99,6 +99,12 @@ static int64_t wrap_timestamp(AVStream *st, int64_t timestamp)
     return timestamp;
 }
 
+#define MAKE_ACCESSORS(str, name, type, field) \
+    type av_##name##_get_##field(const str *s) { return s->field; } \
+    void av_##name##_set_##field(str *s, type v) { s->field = v; }
+
+MAKE_ACCESSORS(AVStream, stream, AVRational, r_frame_rate)
+
 /** head of registered input format linked list */
 static AVInputFormat *first_iformat = NULL;
 /** head of registered output format linked list */