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Proposed reorganisation of media accessibility [ related to issue 2393]

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Tue, 04 Mar 2008 23:53:11 -0600
To: w3c-wai-gl@w3.org
Message-id: <003d01c87e85$32560ef0$0f6fa8c0@NC84301>

 Based on last weeks discussion - a revised reorganization is provided below


 

This version pulls language from TEITAC that makes our provisions read a bit
better.

 

 

Changes from our current text that are 

1)       MEDIA, TEST, SENSORY is broken into three clauses to make it easier
to parse and understand  [also matches TEITAC better]

2)       Audio only and video only are moved to 1.2 which now covers all
media alternatives (other than text alternative for descriptive
identification) 

3)       the word "it" in each provision was changed to "non-text content"
to make them stand alone better

4)       1.1.2 is moved to  1.2 series where it is now 1.2.9   It is also
reworded to match new format but says the same thing. 

5)       1.2 series is reworded to talk about  audio or video "content in
synchronized media" rather than  just captions (or descriptions)  "for
synchronized media".  Means the same thing but eliminates an ambiguity.  

6)       Other changes possible that I don't remember that were discussed
last week and in previous proposals. 

7)       NEW DEFINITIONS are presented at the end. 

 

 

1.1.1 Non-text Content: All
<http://www.w3.org/WAI/GL/WCAG20/#non-text-contentdef> non-text content that
is presented to the user has a
<http://www.w3.org/WAI/GL/WCAG20/#text-altdef> text alternative that
presents equivalent information, except for the situations listed below.
(Level A)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-text-equiv-a
ll> How to Meet 1.1.1
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/text-equiv
-all.html> Understanding 1.1.1

*	Controls, Input: If non-text content is a control or accepts user
input, then it has a  <http://www.w3.org/WAI/GL/WCAG20/#namedef> name that
describes its purpose. (See also Guideline 4.1
<http://www.w3.org/WAI/GL/WCAG20/#ensure-compat> .) 

*         Media: If non-text content is media then text alternatives at
least provide descriptive identification of the non-text content. (See
Guideline 1.2 for additional requirements for media.)

*	Test: If non-text content is a test or exercise that
<http://www.w3.org/WAI/GL/WCAG20/#must-nontextdef> must be presented in
non-text format, then text alternatives at least provide descriptive
identification of the non-text content.
*	Sensory: If non-text content is primarily intended to create a
<http://www.w3.org/WAI/GL/WCAG20/#sensoryexpdef> specific sensory
experience, then text alternatives at least provide descriptive
identification of the non-text content.
*	 <http://www.w3.org/WAI/GL/WCAG20/#CAPTCHAdef> CAPTCHA: If the
purpose non-text content is to confirm that content is being accessed by a
person rather than a computer, then text alternatives that identify and
describe the purpose of the non-text content are provided, and alternative
forms of CAPTCHA using output modes for different types of sensory
perception are provided to accommodate different disabilities.
*	Decoration, Formatting, Invisible: If non-text content is
<http://www.w3.org/WAI/GL/WCAG20/#puredecdef> pure decoration, or used only
for visual formatting, or if it is not presented to users, then non-text
content is implemented in a way that it can be ignored by
<http://www.w3.org/WAI/GL/WCAG20/#atdef> assistive technology.

 

 

 

Guideline 1.2 Media: Provide alternatives for media
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v.html> Understanding Guideline 1.2

 

1.2.X Audio-only and Video-Only (Prerecorded): A [text alternative] that
presents equivalent information of [prerecorded] [audio-only] and
[prerecorded] [video-only] content is provided except when media is already
an  <http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.1
Understanding 1.2.1

 

1.2.1 Captions (Prerecorded):
<http://www.w3.org/WAI/GL/WCAG20/#captionsdef> Captions are provided for all
[prerecorded] [audio] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
except when media is already an
<http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.4
Understanding 1.2.4

 

1.2.2 Audio Description or Full Text Alternative: A
<http://www.w3.org/WAI/GL/WCAG20/#fullmultaltdef> full text alternative for
synchronized media including any interaction  or
<http://www.w3.org/WAI/GL/WCAG20/#audiodescdef> Audio description of the
[prerecorded] [video] content is provided for
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
except when media is already an
<http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative to
text and is clearly labeled as such. (Level A) How to Meet 1.2.5
Understanding 1.2.5

 

1.2.3 Captions (Live):  <http://www.w3.org/WAI/GL/WCAG20/#captionsdef>
Captions are provided for all [live] [audio] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media..
(Level AA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
real-time-captions> How to Meet 1.2.3
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-real-time-captions.html> Understanding 1.2.3

 

1.2.4 Audio Description:  <http://www.w3.org/WAI/GL/WCAG20/#audiodescdef>
Audio description is provided for all [prerecorded] [video] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
(Level AA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
audio-desc-only> How to Meet 1.2.4
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-audio-desc-only.html> Understanding 1.2.4

 

1.2.5 Sign Language:
<http://www.w3.org/WAI/GL/WCAG20/#sign-languageinterpdef> Sign language
interpretation is provided for all [prerecorded] [audio] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
sign> How to Meet 1.2.5
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-sign.html> Understanding 1.2.5

 

1.2.6 Audio Description (Extended):
<http://www.w3.org/WAI/GL/WCAG20/#extended-addef> Extended audio description
is provided for all [prerecorded] [video] content in
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
extended-ad> How to Meet 1.2.6
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-extended-ad.html> Understanding 1.2.6

 

1.2.7 Full Text Alternative: A
<http://www.w3.org/WAI/GL/WCAG20/#fullmultaltdef> full text alternative for
synchronized media including any interaction is provided for [prerecorded]
<http://www.w3.org/WAI/GL/WCAG20/#synchronizedmediadef> synchronized media.
(Level AAA)
<http://www.w3.org/WAI/WCAG20/quickref/20071218/Overview.php#qr-media-equiv-
text-doc> How to Meet 1.2.7
<http://www.w3.org/WAI/GL/WCAG20/WD-UNDERSTANDING-WCAG20-20071218/media-equi
v-text-doc.html> Understanding 1.2.7

 

1.2.9 [was 1.1.2]  Live Audio-only: A
<http://www.w3.org/WAI/GL/WCAG20/#text-altdef> text alternative is provided
that presents equivalent information for [live] [audio-only] content. (Level
AAA) How to Meet 1.2.8 Understanding 1.2.8

 

 

 

Definitions:

 

audio

the technology of sound reproduction

Note: audio can be created synthetically (including speech synthesis), or
recorded from real world sounds, or both.

 

audio description 

narration added to the soundtrack to describe important visual details that
cannot be understood from the main soundtrack alone 

Note 1: Audio description of video provides information about actions,
characters, scene changes, on-screen text, and other visual content. 

Note 2: In standard audio description, narration is added during existing
pauses in dialogue. (See also
<http://www.w3.org/WAI/GL/WCAG20/#extended-addef> extended audio
description.)

Note 3: Where all of the video information is already provided in existing
audio, no additional audio description is necessary

Note 4: Also called "video description" and "descriptive narration."

 

audio-only 

a time-based presentation that contains only [audio] (no [video] and no
interaction)

video-only 

a time-based presentation that contains only [video] (no [audio] and no
interaction)

live

information captured from  a real world event and transmitted to the
receiver within 30 seconds of the occurrence of the event 

Note: If information is completely computer generated, it is not live. 

 

pre-recorded

 

information that is not [live]

 

 

synchronized media 

[audio] or [video] synchronized with another format for presenting
information and/or with time-based interactive components, unless the media
is an  <http://www.w3.org/WAI/GL/WCAG20/#multimedia-alt-textdef> alternative
to text which is clearly labeled as such

 

video 

the technology of moving or sequenced pictures or images

Note: video can be made up of animated or photographic images, or both.

 

 


Gregg
 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 

 

 



Received on Wednesday, 5 March 2008 05:53:37 GMT

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