[Matroska-devel] File with no SeekHead

Moritz Bunkus moritz at bunkus.org
Fri Sep 14 23:35:32 CEST 2012


Hey,

you have to place at least one seek head before the first clusters.
Players usually only scan a file sequentially up to the first cluster
and evaluate all SeekHeads found until then (a player should do this
recursively, meaning if it finds a SeekHead before the first cluster
then it should also evaluate the SeekHeads pointed to in that first
SeekHead etc).

That EbmlVoid element contains enough space for a SeekHead pointing to
the SeekHead at the end of the file, for example. If that EbmlVoid
wasn't there then you could also relocate the whole SegmentTracks
element to the end of the file and use the resulting space for your
first SeekHead. Just make sure to make that SeekHead point to the
relocated SegmentTracks element if you do that.

In your case you only have a SeekHead at the end of the file.
Therefore most players will not find the tags, attachments and
chapters. They're also not required to scan the end of the file for
SeekHeads.

Kind regards,
mosu


More information about the Matroska-devel mailing list