[Theora-dev] Ogg spec

Robert Brautigam robert.brautigam at jmind.hu
Thu Nov 11 16:35:13 PST 2004

On Fri, Nov 12, 2004 at 09:59:34AM +1000, Michael Smith wrote:
> On Friday 12 November 2004 10:53, Robert Brautigam wrote:
> > there can be 255 segments in a page, 255 bytes each + 27 bytes header =
> > 65052. But later it states the maximum size of a page is 65307 which is
> > strangely 255*256+27. Now where does that extra segment come from?
> There's no extra segment: your extra 255 bytes are the lacing table itself 
> (which, in a maximally-sized page, obviously takes up 255 bytes to describe 
> the 255 segments!)

Well, that's at least a good introduction on my part :) (New to the
list, and all...)

[...nil page with no lacing or with a single 0 lacing...]
> It looks to me like it might be a mistake in the RFC - but it'd only make a 
> difference in the case I described before, and I can't really see why you'd 
> actually want to use a empty page in that case. Obviously, in a decoder, you 
> can handle both correctly fine - I assume you want to know what your encoder 
> should do? I'd probably match what libogg does.

Yes, that was the intent, as I couldn't imagine what a true 'nil' page 
should do, as opposed to the 0 lacing value, which is required by rfc if
a packet ends exactly on page end.

Anyway, thanks for the help!

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