[Matroska-devel] Re: Multi-Angle

Paul Bryson paul at msn.com
Fri Sep 17 00:28:29 CEST 2004


"Steve Lhomme"wrote...
> - handle each angle as a separate video track

For files with multiple video tracks, current splitters will only show the 
first track. (Previously all tracks were shown at the same time but Gabest 
'fixed' this.)  Assuming you are writing a new splitter anyway, this 
shouldn't be to much of an issue.  Of course, you will have to write a video 
switcher, and that might make life quite interesting.

In one example, if you had an alternate angle for a scene from 06:34 to 
08:15, then you would create a second video track with the first Block at 
06:34 and the last Block at 08:15.  Then when you mux the tracks together, 
the different angles will occupy the same physical location of the file 
making switching from one to the other much more seamless.  (Also makes it 
possible to use multi-angle while streaming.)

> - put the angles in the same track sequentially, and jump to other part of 
> the movie when using "managed" chapters (a bit ugly, especially 
> timecode-wise)

This seems like a perfectly viable option, and would work for current 
players, the exception being that they would at some point show all of the 
angles if the entire file is played back.  One possible drawback is that 
when using the multi-angle feature, you are almost garaunteed to have a 
slight pause as the player has to seek to another point in the file.  Some 
good buffering could take care of this, but that adds complexity.

> - add support in Matroska frames/block for an angle number.

This seems completely unecessary as either of the other two options should 
work.

> IMO the latter is the cleanest. Any opinion ?

Honestly, either of the first two should be viable options, though one is 
likely to work better than the other.  Assuming that making a video switcher 
does not prove to be to difficult, I think that I would vote for the 
multiple-tracks method.  However the single track method seems perfectly 
reasonable.


Atamido 






More information about the Matroska-devel mailing list