1.3 etc. timedependent links in SMIL image/videomaps

I promised to check out that also the timedependent (or spatial) links
inside image or video maps in SMIL (http://www.w3.org/TR/SMIL-access/#Maps)
remain accessible when navigating through them. Here is an example of this
kinds of links defined by using "anchor" elements with "href" links
(without "href" it just defines a target that can be linked to).

<video title="Introduction to W3C Activities"
          alt="W3C Activities"
          longdesc="http://www.w3.org/Activity/Summary"
          src="http://www.w3.org/CoolStuff.rm">
     <anchor href="http://www.w3.org/AudioVideo" 
             coords="0%,0%,50%,50%"
             title="W3C Multimedia Activity"/>
     <anchor href="http://www.w3.org/Style"      
             coords="50%,50%,100%,100%"
             title="W3C Style Sheet Activity"/>
</video> 

Now, I would like to be able to include these "links" to the list when I'm
tabbing through active elements. We may need to explicitly say it in the
techniques which elements are active in different languages. I'm not sure
if the tabbing is through all the active elements or just the ones that are
active to the user at that time (maybe the user should be able to choose).

In addition, it would be nice to be able to ask the user agent to provide
textual links based on the SMIL image map information when the user prefers
to see the links as text (this might be good for with physical impairments,
so that the user sees there are interesting links and can pause the
presentation and follow the links). If the text links are already provided
by the author, there is no need for the automatic links. However, it might
be difficult for the UA to know it - so also for this reason the user needs
to control turning on/off.

The guidelines related to this are 1.3, 2.4, 7.4 and 7.5 which talk about
image maps and active elements or text alternatives. However, the
techniques do not explicitly say that what elements should be counted as
active elements in different languages and that textual alternatives should
be provided when the user prefers it.

Also SMIL image maps are different from HTML image maps are in 1.3 we only
have HTML version. SMIL has ANCHOR elements with "href" instead of area and
only "title" attribute is available for these links (maybe we should try to
get "alt" to next version of SMIL).

(Here is an example of spatial image map in SMIL:

<video src="http://www.w3.org/CoolStuff.rm">
  <anchor href="http://www.w3.org/AudioVideo" 
          coords="0%,0%,50%,50%"
          title="W3C Multimedia Activity"/>
  <anchor href="http://www.w3.org/Style"      
          coords="50%,50%,100%,100%"
          title="W3C Style Sheet Activity"/>
</video>)

Marja

Received on Friday, 26 November 1999 19:25:20 UTC