[vorbis] xml stream formats

[Ralph Giles]

On Thu, 6 Jul 2000, Michael Smith wrote:

> >Hrm, then would we be streaming Complete XML 'pages' (not to be confused
> with 
> >Ogg pages) as seperate, self-sufficient entities?
> >
> >Metadata does have to stream.
> 
> Let me say this again: You CANNOT, in general, stream XML. 

I think what Monty meant here is that the metadata has to be stuck in a
logical bitstream and optionally sent over a net connection. For static
metadata, it would be ok to stick it all at the beginning of the
file/stream and wait until it's all across before parsing.

> There are two ways in which you can do it: either make the DTD you're using
> VERY limited, and then do some really ugly horrid hacky stuff at the start
> and end, or do something that ISN'T quite XML, though it might be close.
> 
> The second solution is definately unacceptable.

Can you be more specific here?

> People, please think about this really hard before deciding that XML (or
> anything XML based) is the way to go. It's a neat technology, but it's NOT
> suited to everything. I rather think that this is one of the cases where it
> isn't suitable. 

I feel like we may be having pronoun trouble here. I at least, haven't
been expecting to be able to stream xml with an arbrary DTD. As I
understand it, Ogg bitstreams have a head, a body, and a tail. What's
wrong with constucting the DTD for the so-called timecoded data so that
it neatly divides into those same three sections and parsing it
incrementally?

If the DTD-subspace limitation means it's not really xml, that's fine. The
main thing that's attractive to me is being able to mark up the text, and
build on the familiarity of the <tag> model. I think our design
requirement is just that the encoder needs to be able to split the
timecoded xml in such a way that it can be (efficiently) parsed in time
for synchronized display. What am I missing here?

 -r

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