Enable AVFMT_GENERIC_INDEX for Ogg demuxer. This avoids the many

seeks needed for binary search when seeking to a previously seen
location.

Originally committed as revision 23279 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/oggdec.c

@@ -642,4 +642,5 @@ AVInputFormat ogg_demuxer = {
     ogg_read_timestamp,
     .extensions = "ogg",
     .metadata_conv = ff_vorbiscomment_metadata_conv,
+    .flags = AVFMT_GENERIC_INDEX,
 };