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Re: Issues raised during discussion with RealNetworks and Microsoft

From: Al Gilman <asgilman@iamdigex.net>
Date: Sat, 21 Apr 2001 13:03:54 -0400
Message-Id: <200104211700.NAA11314462@smtp2.mail.iamworld.net>
To: Ian Jacobs <ij@w3.org>
Cc: w3c-wai-ua@w3.org
At 12:02 PM 2001-04-21 -0400, Ian Jacobs wrote:
>Al Gilman wrote:
[...]
>> >----------------------------------------------------------
>> >Issue 6: Checkpoint 4.6: Captions positioning
>> >[Proposal]
>> >----------------------------------------------------------
>> >
>> >What happens when the author has laid out captions with some
>> >particular constraints (e.g., take up fifty percent of the
>> >parent's available horizontal width and be centered within that
>> >width)? Should the user be able to override that? What happens to
>> >the rest of the layout?
>> >
>> >Checkpoint 4.6 reads: "For graphical viewports, allow the user to
>> >position text transcripts, collated text transcripts, and
>> >captions in the viewport." However, I can imagine techniques
>> >(that might even address the previous question) where a solution
>> >would be to render the captions in a separate viewport (i.e., not
>> >in the same viewport, which is suggested by the end of 4.6). Did
>> >we mean to exclude the technique of rendering in a separate (and
>> >positionable) viewport?
>> >
>> >Proposed:
>> >
>> ><NEW 4.6>
>> >  "For graphical viewports, allow the user to position text
>> >  transcripts, collated text transcripts, and captions in the
>> >  same or another viewport."
>> ></NEW 4.6>
>> >
>> >For example, the user might be able to select captions and
>> >"extract them" from the presentation into a second viewport,
>> >leaving the layout otherwise intact.
>> >
>> 
>> AG:: I do not concur with this proposal.  In the earlier discussion, we
>> pointed
>> out that this positioning capability was so a low vision user could control
>> what portion of the video is adjacent to the captions and hence visible
within
>> the cropped effective viewport along with the captions when the user is
>> using a
>> high power of magnification.  Moving the captions into a separate window
>> prevents the user from having the juxtaposition capability they need.
>
>IJ: I'm not sure I agree. I was aware of this case when I made
>the proposal. It seems like an implementation detail to me whether
>the captions track is moved to a global x,y that happens to
>be in the same viewport, or whether it is put in a new viewport
>that is then moved to the same global x,y. One difference might be
>that the new viewport has chrome to it, and that chrome might get
>in the way of the video content behind it. But suppose it doesn't
>have a lot of chrome? Then it seems to me to provide the same
>functionality, but the ability to move the viewport is provided
>by the windowing system, not the user agent directly.
>

I begin to see what you are thinking.  But I am not sure you can, in the
visual
presentation technology that people are using today, get a transparent
background in that "new viewport" such that only the text obscures the video,
and the video content shows through as the background for the text.

If the "new viewport" can be made such that the text is all that shows in that
viewport, the background area not filled by the glyphs of the text is
transparent, and the positioning of the new viewport is free so the text can
overlay the video in any relative relationship as chosen by the user, then
"same or different viewport" is indeed a technicality not bearing on the
requirement.  I guess I was translating your "a new viewport" as "another
window" and presuming that windows start with an opaque layer at the back.

Al 
Received on Saturday, 21 April 2001 13:00:56 GMT

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