[theora] Indexing Ogg files for faster seeking

Silvia Pfeiffer silviapfeiffer1 at gmail.com
Thu Oct 8 17:50:45 PDT 2009

I think Chris Pearce's new proposal supports this.

On Sun, Sep 27, 2009 at 12:40 AM, Carlos Jose Lenarts Ramis
<godaxen at gmail.com> wrote:
> I think that better to an index per track is to have a global index, but if
> it has each track index multiplexed, the main difference is that we don't
> have n key-points wee have n key-points per track, then the number of
> key-points are also related to the number of tracks and each key points is
> marked, this add a little more of overhead. In this approach each track can
> have a different number of key-points for example the key-points for a
> subtitle marks the lines but in a video it marks each 500ms. The only
> modification to the original idea is to ad a track identifier in the
> key-points, the results is that key-point have this information:
> the page offset as an 8 byte unsigned integer, followed by
> the checksum of the page found at the offset, as a 4 byte field,followed by
> the ther refered bitstream serial number of the track, as a 4 byte
> field,followed by
> the presentation times in milliseconds of the key point, as an 8 byte
> unsigned integer.
> To make a search in this approach is litle more complex as we have to check
> that the refereed key-point if from a active track, but that complexity is
> negligible. Also to make the index in this approach is more complex but not
> much.
> _______________________________________________
> theora mailing list
> theora at xiph.org
> http://lists.xiph.org/mailman/listinfo/theora

More information about the theora mailing list