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Media (issues 2393, 2490, 2487 and 2488)

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Wed, 20 Feb 2008 16:35:53 +0000
To: WCAG <w3c-wai-gl@w3.org>
Message-ID: <90EEC9D914694641A8358AA190DACB3D1B3C914D29@EA-EXMSG-C334.europe.corp.microsoft.com>

In thinking about issues 2393, 2490, 2487 and 2488; I've come up with an approach for your consideration which might provide a new ending to this book.

Basically I feel at level A we need to ensure that using media does not block the user; captions and AD while desirable, would then not be essential to access but rather be providing a more comparable experience, and not be required in all circumstances, and thus could go to AA.

The logic of the current draft is pretty convoluted right now, and I think we actually have a bit of a structural issue with the overlap of 1.1.1 and parts of 1.2
Currently: synchronised media (SM) requires a text alternative (1.1.1) which can be a descriptive identification, it also requires captions by virtue of 1.2.1. So do both of these apply? It also requires a full text alternative (1.2.2) - although I think this may have been is meant to be an alternative option, the wording of 1.2.2 prevents this since the first option applies only to video - which is not synchronised media.

So at level A, as far as I can ascertain from the complex logic we need:
  Audio - text equivalent (method undefined)
  Video - text equivalent (method undefined)
  SM (whether it contains audio or not) - description and captions and full-text
  Audio - description
  Video - description
  SM - description

My Alternative Proposal:

PART 1 : Adjust 1.1.1 to split media out as a separate catch all exception, and defer its complete handling to section 1.2; thus simplifying the logic greatly.

1.1.1 ....
*       Media: If it is synchronized media,  audio-only or video-only content see 1.2
*       Test, Sensory: If it is (1) a test or exercise that must be presented in non-text format, (2) primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content , or (3) a media alternative to text that is clearly labelled as such.

Add a new 1.2.1 which prevents the use of media from blocking usage of the page, but without requiring captions and/or audio description.

1.2.1 Media Non Blocking: synchronized media, audio-only or video-only content is not used as the only means of conveying essential information, indicating an action or prompting a response, and a descriptive identification is provided (Level A) How to Meet 1.2.1 Understanding 1.2.1

Move captions and AD to level AA as better accessibility features, merging live and prerecorded (thus we can avoid defining those terms)

1.2.2 Captions: Captions are provided for synchronized media containing audio content, or audio only content, except if the synchronized media or audio is an alternative to text and is clearly labelled as such. (Level AA) How to Meet 1.2.1 Understanding 1.2.1

1.2.3 Audio Description or Full Text Alternative: Audio description, or a full text alternative for synchronized media including any interaction , is provided for synchronized media containing video (Level AA) How to Meet 1.2.2 Understanding 1.2.2

-- the existing 1.2.3 and 1.2.4 would get deleted. 1.2.{5,6,7} would remain as is.

It's a bit radical and late in the game I know, but IMO it greatly simplifies the draft, does not throw the baby out with the bathwater and make media completely inaccessible, and is far more pragmatic in terms of what can be achieved at level A.


Sean Hayes
Incubation Lab
Accessibility Business Unit

Office:  +44 118 909 5867,
Mobile: +44 7875 091385
Received on Wednesday, 20 February 2008 16:36:05 UTC

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