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RE: necessity of extended/enhanced alternatives, WAS Adopting the media accessibility requirements

From: Geoff Freed <geoff_freed@wgbh.org>
Date: Sat, 30 Oct 2010 13:15:08 -0400
To: Henri Sivonen <hsivonen@iki.fi>, HTML WG <public-html@w3.org>
Message-ID: <B3526F4AC3C3C64388BF661A8B2112A767958A7A85@EXCHCCR.wgbh.org>

Hi, Henri:

One comment from a section which I've extracted below.
Geoff Freed


> Alternative Content Technologies:
> We have identified the following types of Alternative Content (and
> Technologies) used to accommodate users with a variety of impairments:
> * Described video
> * Text video description
> * Extended video descriptions
> * Clear audio
> * Content navigation by content structure
> * Captioning
> * Enhanced captions/subtitles
> * Sign translation
> * Transcripts
> Do you disagree with any of these alternative content types and
> technologies?
> If so, which and why?

I disagree about the essentiality of "extended" and "enhanced". If you believed that those features were absolutely essential for achieving accessibility, you wouldn't call then "enhanced" or "extended".

"Extended" and "enhanced" are necessary from a historical perspective.  Both captions and video descriptions originated in the broadcast world, having been introduced nearly 40 and 30 years ago, respectively.  Captions could only be timed to be visible during the normal video timeline, and video descriptions were timed to be inserted into the natural pauses of dialog or narration.  For decades, this has been the accepted "regular" state of captions and descriptions.  In non-broadcast situations-- i.e., the Web-- however, it is possible to use markup language such as SMIL (or other means) to automatically pause the video and program-audio tracks in order to play a video description that would normally be too long to fit into a regular pause in dialog or narration; hence the term "extended video description."   And captions, which historically made visual only what is conveyed in the audio track (i.e., dialog and sound effects), can be extended/enhanced by carrying other information, such as links and definitions.  Or, as with extended descriptions, they can convey more information than is carried in the program-audio track:  during a recorded lecture, for example, the author can pause the whole presentation and play a text track that explains what the professor just said.  For these (and other) reasons, it is, in fact, important to distinguish between regular and extended/enhanced descriptions or captions.  
Received on Saturday, 30 October 2010 17:15:43 UTC

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