[Matroska-devel] DVD Still Cells

Steve Lhomme steve.lhomme at free.fr
Sat Jan 1 18:56:59 CET 2005


Hi,

As you know DVD have menus...

In these menus you have still frames (when the menu is static). That 
means that the cell should play for a certain time looping, or even for 
an infinite looping time (still time of 255s = infinite) !

I don't know exactly how still frames should be handled. But so far I 
only saw them without audio. But they can contain buttons (and subs), 
hopefully for an infinite frame...

We should handle that in Matroska too. There are 2 main options: in the 
Cluster and in the Chapter.

Actually each case (infinite and non) can probably be handled differently.

In the case of the infinite loop, we can't afford to put that in the 
Cluster. Because, as Matroska is modular, we should be able to play a 
file even if there is no Chapter. And the only way to get out of an 
infinite loops is to use events handled in the Chapter codecs. That 
means this information has to be handled close to chapter codecs.

In the case of the finite loop, we can just change the framerate of the 
frame(s) to make the sequence last as specified in the cell. I already 
create a timecode file for video (similar to what is used for VFR). So 
that part is very easy and doesn't need any change.

Any comments ?

-- 
robUx4 on blog <http://robux4.blogspot.com/>



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