W3C home > Mailing lists > Public > public-tt@w3.org > February 2003

RE: some points w.r.t. streaming and buffering scenarios

From: <Johnb@screen.subtitling.com>
Date: Tue, 11 Feb 2003 09:39:37 -0000
Message-ID: <11E58A66B922D511AFB600A0244A722E093EC7@NTMAIL>
To: lists@wiltgen.net, public-tt@w3.org

> I wrote...

> > I'm not against using XML per se, but have to agree with Al that if it
> > gets in the way..... My concern with XML is that it is a single
hierarchy
> > of nesting.
 
> I think you're confusing XML with some XML applications you 
> may have seen.

Possibly :-)

>  Can you elaborate?

Well - let's see - In XML, AFAIK, everything is under a single root. So in
proposal 0.0 you can only have one structure to the document, one hierarchy.
This means that in order to find and manipulate the document- you have to
search it from an end. I can believe that this restrictive structure might
bias the implementation of a flexible TT format - since it is based on an
assumption that the document is read from top towards the bottom....

There appears to be a view that TT is a linear format - but I see a need for
more random access.

e.g.

<program>
<langA>
<subtitle>
<\subtitle>
<subtitle>
<\subtitle>
<subtitle>
<\subtitle>
<\langA>
<langB>
<subtitle>
<\subtitle>
<subtitle>
<\subtitle>
<subtitle>
<\subtitle>
<\langB>
<\program>

> > IMHO this requires that the text, authors suggested presentation style
and
> > timing elements are all 'separate' from each other.

> Proposal 0.0 separates content from presentation.  Can you describe the
> problem you're trying to solve so that I can show you how it might work?

It's not so much a specific problem - rather a feeling based on experience -
that suggests to me that if it is possible to separate the timing of
elements - in the same way that style is separated - then that will lead to
a better format.

> > Secondly - SMIL and XML are heavyweights - both result in very large
files
> > to do relatively small things.

> Are you familiar with HTML?   :^)   Seriously, (1) this is 
> basically a myth (modems compress text content exceptionally well), (2)
HTTP 
> 1.1 supports compression on top of that, and (3) since it's based on XML,
standards
> under way for XML compression will work with TT as well.

Yes, it's obvious that a text based human readable format will compress well
for transmission - but it has to exist in an uncompressed format for
manipulation.... HTML uses <p> <\p> <\br> style tags, **most** XML I've seen
tends towards a much more verbose tagging.

regards 
John Birch

The views and opinions expressed are the author's own and do not necessarily
reflect the views and opinions of Screen Subtitling Systems Limited.
Received on Tuesday, 11 February 2003 04:30:49 GMT

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