set average frame rate in mov demuxer

Originally committed as revision 21310 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/mov.c

@@ -1652,14 +1652,18 @@ static int mov_read_trak(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
     } else
         sc->pb = c->fc->pb;
 
-    if (st->codec->codec_type == CODEC_TYPE_VIDEO &&
-        (st->codec->width != sc->width || st->codec->height != sc->height)) {
+    if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
+        if (st->codec->width != sc->width || st->codec->height != sc->height) {
         AVRational r = av_d2q(((double)st->codec->height * sc->width) /
                               ((double)st->codec->width * sc->height), INT_MAX);
         if (st->sample_aspect_ratio.num)
             st->sample_aspect_ratio = av_mul_q(st->sample_aspect_ratio, r);
         else
             st->sample_aspect_ratio = r;
+        }
+
+        av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
+                  sc->time_scale*st->nb_frames, st->duration, INT_MAX);
     }
 
     switch (st->codec->codec_id) {

libavformat/utils.c

@@ -2218,7 +2218,7 @@ int av_find_stream_info(AVFormatContext *ic)
     }
     for(i=0;i<ic->nb_streams;i++) {
         st = ic->streams[i];
-        if(codec_info_nb_frames[i]>2)
+        if(codec_info_nb_frames[i]>2 && !st->avg_frame_rate.num)
             av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
                      (codec_info_nb_frames[i]-2)*(int64_t)st->time_base.den,
                       codec_info_duration[i]    *(int64_t)st->time_base.num, 60000);