@@ -668,6 +668,11 @@ static void compute_frame_duration(AVFormatContext *s, int *pnum, int *pden,
if (st->r_frame_rate.num && (!pc || !codec_framerate.num)) {
*pnum = st->r_frame_rate.den;
*pden = st->r_frame_rate.num;
+ } else if ((s->iformat->flags & AVFMT_NOTIMESTAMPS) &&
+ !codec_framerate.num &&
+ st->avg_frame_rate.num && st->avg_frame_rate.den) {
+ *pnum = st->avg_frame_rate.den;
+ *pden = st->avg_frame_rate.num;
} else if (st->time_base.num * 1000LL > st->time_base.den) {
*pnum = st->time_base.num;
*pden = st->time_base.den;