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RE: TT and subtitling/captioning - separating timing from style f rom content

From: <Johnb@screen.subtitling.com>
Date: Thu, 7 Aug 2003 16:54:46 +0100
Message-ID: <11E58A66B922D511AFB600A0244A722E0940A0@NTMAIL>
To: public-tt@w3.org
Cc: asgilman@iamdigex.net

>> Assuming that I wish to separate the timing in my TT-AF 
>> document from the content by using references within the timing 'tree' a
la Daisy 
>> model - and assuming that this might be possible!
>> - would it then possible to apply style through the timing tree rather 
>> than by inline markup or attribute within the text content.
> If you are happy to use a SMIL wrapper to sequence and time 
> the presentation,
> you can use the digital talking book specification and you 
> don't need TT-AF
> which will be a more lightweight specification for marking 
> the timing in the
> file with the text content, IIRC.

Hmmm... Not sure about using SMIL I'm unconvinced that it's a good fit with
what I would use TT-AF for.
For one thing the timing model in SMIL doesn't suit external timing - the
synchronisation model is primarily 
internal (if you get what I mean). Happier to use limited SMIL semantics
though..... why re-invent tag names :-)

I will read the DTB spec again - it's close to what I want to do... but a
bit of a tangent from my requirements IIRC.

> Secondly, the best practice is not to apply the style inline 
> in the timing script, but it would be natural to associate a stylesheet 
> cascade with each channel or display region.
> But you still want to put a well-articulated
> display-mode-independent basis for the styling in the markup 
> of the text itself.

I certainly agree that referencing external stylesheets is preferable, 
but what I don't want is to put the reference to the style in the content.
The reason I don't want to do this is because the style desired for the
will need to vary depending upon which of multiple timelines is being
The timelines are in effect the description of how the content is 
presented temporally for a specific display. Specific displays have
limitations that
prevent the adequate representation of certain styles, limitations on line
lengths and line breaking etc.

I'm also not really angling after the issue of user defined style sheets - I
don't think that is particularly
relevant in an **authoring format**.  

> Why does the text have hard line breaks?  Typical cases are lists and
The line breaks were in the example I snipped from a GA post and were not
to imply any behaviour other than differentiating the two pieces of text. 
Please ignore them and just consider it as 'text line one' and 'second line
of text' 

> CSS provides facilities to apply styles by ID-keyed selctors but this is
> should be avoided.  


> Then encode the basis for the styling decisions in
> [elements and attributes in] the content markup, and key the 
> result to the encoded basis by the selector in your separate style rule.  
> This will give you a rule you can lift and reuse.

But content markup is messy - content and style are two faces of the (three
sided :-) TT coin.
It's not always appropriate to have style inside content - not if you want
to reuse the content in different contexts.

It's a triumvarate

Style + Content + Timing. Ideally none should be intermixed with the other.

Note: Ive spooled the temporal flow off into a separate response to Glenns
recent post....

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 Thursday, 7 August 2003 11:45:36 UTC

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