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RE: Timed Text Authoring Format - Distribution Format Exchange Pr ofile (DFXP)

From: <Johnb@screen.subtitling.com>
Date: Thu, 17 Mar 2005 16:00:48 -0000
Message-ID: <11E58A66B922D511AFB600A0244A722EE57D87@NTMAIL>
To: public-tt@w3.org
Glenn,
 
Just to bottom this thread....
 

The timing attributes were added to <tt/> to support timing on <set/>
children of <region/> whose ancestors are <layout/>, <head/>, then <tt/>.

 

I'm not exactly sure what you can do with timing in both the body and tt
elements that cannot be achieved just in the body element, but it was more
of a question than an issue.... 
 
As regards the mixed alignment line, it is an uncommon scenario (though not
as uncommon as might be thought - since saving space is often an issue in
subtitling). I guess XSL-FO is bound by preconceptions of the web-page as
output - since, as you identify, support for such features exists in print
oriented languages. 
 
Can the fo:inline-container object be used to support the mixed alignment
line concept?
 
In the absence of the ability to set text-alignment on a span, I think
**my** most likely DFXP implementation of this behaviour would be to create
a transparent region for the right aligned section and overlay it. This does
however mean that explicit line breaks and careful authoring would be
required, since otherwise collision would be almost certain to occur.
 
BTW - a conversion of DFXP into XSL-FO is a good validation of DFXP - but I
would suggest that most practical conversions will be direct to the target
distribution format. I.e. for me...  DFXP to Teletext, or DFXP to Line21.
 
best regards John Birch.

-----Original Message-----
From: Glenn A. Adams [mailto:gadams@xfsi.com]
Sent: 17 March 2005 13:53
To: Johnb@screen.subtitling.com
Cc: public-tt@w3.org
Subject: RE: Timed Text Authoring Format - Distribution Format Exchange Pr
ofile (DFXP)



 

 


  _____  


From: Johnb@screen.subtitling.com [mailto:Johnb@screen.subtitling.com] 
Sent: Thursday, March 17, 2005 6:37 AM
To: Glenn A. Adams
Cc: public-tt@w3.org
Subject: RE: Timed Text Authoring Format - Distribution Format Exchange Pr
ofile (DFXP)

 

Glenn,

 

Thanks for the speedy reply - some more comments inline :-)

 

best regards

 

John Birch

-----Original Message-----
From: Glenn A. Adams [mailto:gadams@xfsi.com]
Sent: 16 March 2005 17:55
To: Johnb@screen.subtitling.com
Cc: public-tt@w3.org
Subject: RE: Timed Text Authoring Format - Distribution Format Exchange Pr
ofile (DFXP)

 

7.1.1 tt

If begin and (or) end attributes are specified on the tt element, then they
specify the beginning and (or) ending points of a time interval for a
document instance in relationship with some external application or
presentation context. The temporal begin and end points determined by an
external application or presentation are referred to subsequently as the
external time interval.

Is it necessary to have begin and (or) end attributes for both the tt
element and the body element? Could this be simplified so that begin and
(or) end is only specified on the tt element?

 

No. Neither is required. Is there something in the text that led you to
infer that both were required? 

 

Ahhh.... I didn't make myself clear.... What I meant to say was.... does the
DXFP  specification need to support a begin / end attribute on both the tt
element and the body element? Would it be possible to simplify the DXFP
**specification** by removing timing attributes from one of these elements,
since I cannot see any situation that requires both elements to have timing
attributes. IMHO a document using timing attributes on both tt and body can
be **equivalently** represented by a single set of timing attributes on just
one of these elements. Am I missing something? What is gained by having
timing attributes at both levels in the document hierarchy, given that both
tt and body can only occur once in a document instance?

 

The timing attributes were added to <tt/> to support timing on <set/>
children of <region/> whose ancestors are <layout/>, <head/>, then <tt/>.

 

8.2.19 tts:textAlign

 

Applies to:        p

 

Can we allow tts:textAlign to apply to span as well. Otherwise, I don't
believe it is possible to have:

 


Hello?

 

Come In!

Please have a seat

 

 

No. You cannot do this in a single paragraph. You would have to overlay two
regions on top of one another and have one of them use a transparent
background.  

 

A bit ugly - and prone to problems with text collisions which I would hope
to avoid! Imagine if the second phrase were modified to read "Come In! I've
been waiting to meet you."

 

Text alignment (in the inline progression dimension) applies to the
positioning of line areas within a block area. A text alignment on a span
would always pertain individually to each inline area produced by the span,
and since each such inline area is bounded by glyph areas at both start and
end edges, there would be no extra room in which to move those glyph areas
within the inline area.

 

Is there no way to createan inline block area that fills to the end of the
line (region)? I am assuming that the DXFP for the above would be:

 

<p id="subtitle5" begin="10:00:00:00" end="10:00:05:00"
style="rightaligned">

<span tts:textAlign="left">

Hello?

</span>

<span begin="10:00:02:00">

Come In!</br>Please have a seat

</span>

</p> 

 

Or:

 

 

<p id="subtitle5" begin="10:00:00:00" end="10:00:05:00"
style="rightaligned">

<span tts:textAlign="left">

Hello?

</span>

 

<span begin="2:00">

Come In!

</br>

</span>

</p> 

<p id="subtitle 6 " begin="10:00:02:00" end="10:00:05:00"
style="rightaligned">

Please have a seat

</p> 

 

 

So why can the first span not create an inline area that is left aligned
within the region and contains the text Hello?, terminating in area just
after the ? When the second span activates - can the inline area generated
not stretch from the previous inline area until the end of the line - there
is an explicit break in the first example and an implicit break in the
second?

 

We base our basic formatting/layout semantics on XSL 1.0, which does not
support text-align on inline-level formatting objects. The closest feature
in XSL that would support this would be the use of inline margins, e.g.,

 

<fo:block text-align="end">

<fo:inline>Hello?</fo:inline>

<fo:inline space-start.minimum="0px" space-start.maximum="200px"
space-start.opt="200px">Come In!</fo:inline>

<fo:character character="&#x000A;"/>

<fo:inline space-start.minimum="0px" space-start.maximum="200px"
space-start.opt="200px">Please have a seat</fo:inline>

</fo:block>

 

Supporting this in DFXP would require introducing an equivalent of the
space-* properties of XSL, which involves a level of complexity that may not
be appropriate for this profile (and will certainly require discussion by
the WG).

 

If I were using TeX, I would handle by inserting an \hskip or \hfil command
possibly with a \penalty command before or after to adjust line break
precedence rules.

 

Another, but more complex means for handling this would be to introduce a
construct or mechanism that works similar to TAB in traditional word
processors.  

 

Ugghhhh! Really really Ugghhhh! 

I am not sure how you could use a tab construct, you would need to position
the tab by knowing how long the rendered second phrase (the right aligned
part) was - since the right aligned part would actually be left aligned to
the tab. 

 

Another way to handle, but using a simpler, yet manual approach, would be to
use multiple non-breaking spaces before "Come" and "Please". 

 

Ugghhhh!

Thisapproach would not work for regions that were specified with relative
(proportionate) sizes and would not achieve the same results for different
font sizes (or indeed fonts). Admittedly, this is how the above effect is
currently achieved though!

 

I suspect this is what you will end up doing in DFXP as well.

 

Regards,

Glenn

 

 


  _____  


From: Johnb@screen.subtitling.com [mailto:Johnb@screen.subtitling.com] 
Sent: Wednesday, March 16, 2005 10:48 AM
To: public-tt@w3.org
Subject: RE: Timed Text Authoring Format - Distribution Format Exchange Pr
ofile (DFXP)

 

Glenn, et al, 

I have a number of minor comments / questions regarding the draft that I
have placed in the attached Word document. Apologies for using this format
but it allows me to easily illustrate certain points regarding formatting
without generating images.

I have a couple of other points that I will make in separate emails. 

with best regards 
John Birch. 

 

-----Original Message----- 
From: Glenn A. Adams [ mailto:gadams@xfsi.com <mailto:gadams@xfsi.com> ] 
Sent: 14 March 2005 16:51 
To: public-tt@w3.org 
Subject: Timed Text Authoring Format - Distribution Format Exchange 
Profile (DFXP) 

 

A new update of the Timed Text Authoring Format 1.0 - Distribution 
Format Exchange Profile (DFXP), is now available at [1]: 

http://www.w3.org/TR/2005/WD-ttaf1-dfxp-20050314/
<http://www.w3.org/TR/2005/WD-ttaf1-dfxp-20050314/>  

The TT WG solicits your comments on this new draft as soon as possible, 
as a very rapid turn-around is expected in order to publish a first Last 
Call (LC) draft. 

Please sent comments either to this list or, if you prefer privacy, to 
me directly. 

Regards, 
Glenn Adams 

 

  
Received on Thursday, 17 March 2005 15:45:40 GMT

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