[Matroska-devel] EBML specification component for review - Element Data Size

Jerome Martinez jerome at mediaarea.net
Sat May 2 19:02:49 CEST 2015

Le 02/05/2015 18:48, Steve Lhomme a écrit :
> But in that case that's just a temporary state of the file, in the end 
> the file has a size set. We use this technique extensively with 
> Matroska muxers.

Why not keeping such possibility in the EBML spec?
It is used, I don't think it is so much complex to specify how is a file 
during the muxing (actually just saying that the unknown element size 
can be everywhere and is considered as the last element)

> You can't expect a specification to cover files created by a program 
> that crashed.

a file permanently in a "temporary state" can have different causes 
(muxer crash, OS crash, disk failure, network failure, power failure...)
I already saw such file (actually MXF files because MXF is also a lot 
used) in memory institutions or broadcasters, and having a standardized 
method for setting setting the temporary state allows to easily retrieve 
content from such file.

I would not limit (in the spec) the possibility to have an unknown 
element size especially because you use this technique extensively with 
Matroska muxers.

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