<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Please delete me from mailing list....Thanks<BR><BR><BR><BR>----- Forwarded Message -----<BR>From: "Chris Pearce" <chris@pearce.org.nz><BR>To: theora@xiph.org<BR>Sent: Tuesday, September 22, 2009 8:35:54 PM GMT -05:00 US/Canada Eastern<BR>Subject: Re: [theora] Indexing Ogg files for faster seeking<BR><BR>On 9/22/2009 11:10 PM, j@v2v.cc wrote:<BR>> would this also work for ogg streams with more than one video, not that<BR>> this is common, but possible in theory. would in those cases an index<BR>> not need to reference the track it is indexing?<BR><BR>Currently my index/indexer merges keyframe data from all streams. So if <BR>you had multiple video streams, and you wanted to seek to time t, the <BR>index would tell you the offset of the last page which lies before <BR>*every* streams' last keyframe before t.<BR><BR>If you're only playing one of the video streams, then you may be seeking <BR>back more than you need to.<BR><BR>We discussed this on #theora yesterday, and most people seemed to favour <BR>indexing stream individually, or having mulitple indexes which denote <BR>what stream(s) they index.<BR><BR>A sensible use case is for subtitles. A subtitle track could be embedded <BR>with its pages spread much further apart than the keyframes for a video <BR>track. With the streams indexed separately, you could request the pages <BR>with the subtitles with a separate request/read if they're too far away <BR>from the A/V pages.<BR><BR><BR>Chris P.<BR><BR><BR><BR><BR>_______________________________________________<BR>theora mailing list<BR>theora@xiph.org<BR>http://lists.xiph.org/mailman/listinfo/theora<BR></div></body></html>