Re: CP, ISSUE-30: Link longdesc to role of img [Was: hypothetical question on longdesc]

So, the conversation circles back to a key point I tried to make
yesterday (which was not responded to, actually):
http://lists.w3.org/Archives/Public/public-html-a11y/2012Mar/0236.html
Sean Hayes writes:
> >> 1) The <video> element, when containing both a media asset and an
> >> image, now has 2 objects that require a longer textual description.
> 
> >OK, there is the problem, it doesn't.  It has one object, the video;  you are entrenched in a confused position caused >by the unfortunate choice of the word 'poster'.  Everything else you say is founded on this misapprehension.
> 
> 
> Well let us look at what the spec actually says. I think we have to admit that regardless of its name there is definitely the possibility of an image:
> 
> <quote>The poster attribute gives the address of an image file that the user agent can show while no video data is available. The attribute, if present, must contain a valid non-empty URL potentially surrounded by spaces. </quote>
> 
> I see nothing in that (normative) text that constrains that image to be a frame of the video.
> 
> We do have the following (informative) note
> 
> <quote>The image given by the poster attribute, the poster frame, is intended to be a representative frame of the video (typically one of the first non-blank frames) that gives the user an idea of what the video is like. </quote>
> 
> So either we change that note to be normative text, replacing "intended to be" with "must be" in which case I would concede Dave's point (although in such a case we should also require that the video description needs to convey a detailed description of the frame in question); or we concede John's point that there currently exists the possibility that the image is not deployed as *intended*, but rather as *allowed*, and is carrying other interesting information which is not in the video that a person who can't see is entitled to be able to perceive.


The fact that authors are so expressly invited to do more fairly well
guarantees it. Regardless of what percentage has this richer content vs.
a blank (or simply a presentational) frame, the need for the long text
description mechanism should be clear.


As I attempted to say yesterday, provide the mechanism or pull the
opportunity for rich image content out of the spec. But, don't expect
accessibility to agree that we can let it slide. We can't.

Janina

-- 

Janina Sajka,	Phone:	+1.443.300.2200
		sip:janina@asterisk.rednote.net

Chair, Open Accessibility	janina@a11y.org	
Linux Foundation		http://a11y.org

Chair, Protocols & Formats
Web Accessibility Initiative	http://www.w3.org/wai/pf
World Wide Web Consortium (W3C)

Received on Wednesday, 21 March 2012 20:47:34 UTC