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Re: UAAG 2.0 guidelines for video AND AUDIO

From: Janina Sajka <janina@rednote.net>
Date: Tue, 18 May 2010 19:07:08 -0400
To: Jim Allan <jimallan@tsbvi.edu>
Cc: "'HTML Accessibility Task Force'" <public-html-a11y@w3.org>, "'WAI-UA list'" <w3c-wai-ua@w3.org>, "'John Foliot'" <jfoliot@stanford.edu>
Message-ID: <20100518230708.GQ2329@sonata.rednote.net>
Jim, and others;

These are important requirements. Can you either past them into
directly, or perhaps by URI reference, into the requirements document
the HTML-A11y Task Force Media Subteam is using to gather requirements:


http://www.w3.org/html/wg/wiki/Accessibility_Requirements_of_Media


Please note that we may move this resource following the Media telecon
call this Wednesday. It's currently in the HTML-WG Wiki, and probably
should be in the TF Wiki.

Also, while I hate to rush anyone, we're trying to close out
requirements gathering and move to classification (i.e. "must haves for
HTML 5" vs. "could waith for HTML5++). This, inturn, willtake us to gap
analysis and decisions about technology recommendations.

Janina

Jim Allan writes:
> Just a slight title change to better reflect the scope. 
> And a shout out to Mark Hakkinen for collaborating on this document.
> 
> > -----Original Message-----
> > From: Jim Allan [mailto:jimallan@tsbvi.edu]
> > Sent: Tuesday, May 04, 2010 1:51 PM
> > To: 'HTML Accessibility Task Force'
> > Cc: 'WAI-UA list'; 'John Foliot'
> > Subject: UAAG 2.0 guidelines for video
> > 
> > The UAAG Guidelines[1] in their present form are organized by basic
> > principles that, when applied as a whole, provide guidance in ensuring
> > that a user agent and the (accessible) content it renders, and provides
> > interaction with, is accessible.  As such, specific guidelines that
> > apply to multimedia, or as we call it, time-based media, rendering and
> > interaction are found across several of the principles.  This document
> > is a first pass at extracting the guidelines of relevance to the media
> > accessibility subgroup.  Feedback on these guidelines, as well as the
> > overall UAAG document is welcome. The UAAG Implementation document [2]
> > is also available for review.
> > 
> > 
> > PRINCIPLE 2. Facilitate programmatic access
> > 
> > 2.1.1 Platform Accessibility Architecture: Support an platform
> > accessibility architecture relevant to the operating environment.
> > (Level A)
> > 
> > 2.1.2 Name, Role, State, Value, Description: 2.1.2 Name, Role, State,
> > Value, Description: For all user interface components including the
> > user interface, rendered content, and alternative content, make
> > available the name, role, state, value, and description via an platform
> > accessibility architecture. (Level A)
> > 
> > 2.1.3 Accessible Alternative: If a feature is not supported by the
> > accessibility architecture(s), provide an equivalent feature that does
> > support the accessibility architecture(s). Document the equivalent
> > feature in the conformance claim. (Level A)
> > 
> > 2.1.4 Programmatic Availability of DOMs: If the user agent implements
> > one or more DOMs, they must be made programmatically available to
> > assistive technologies. (Level A)
> > 
> > 2.1.5 Write Access: If the user can modify the state or value of a
> > piece of content through the user interface (e.g., by checking a box or
> > editing a text area), the same degree of write access is available
> > programmatically. (Level A)
> > 
> > 2.1.6 Properties: If any of the following properties are supported by
> > the accessibility platform architecture, make the properties available
> > to the accessibility platform architecture: (Level A)
> > 
> > (a) the bounding dimensions and coordinates of rendered graphical
> > objects
> > (b) font family of text
> > (c) font size of text
> > (d) foreground color of text
> > (e) background color of text.
> > (f) change state/value notifications
> > 
> > 2.1.7 Timely Communication: For APIs (for non-web-based user agents)
> > implemented to satisfy the requirements of this document, ensure that
> > programmatic exchanges proceed at a rate such that users do not
> > perceive a delay. (Level A).
> > 
> > PRINCIPLE 3: Perceivable - The user interface and rendered content must
> > be presented to users in ways they can perceive
> > 
> > 3.1.1 Identify Presence of Alternative Content The user has the ability
> > to have indicators rendered along with rendered elements that have
> > alternative content (e.g. visual icons rendered in proximity of content
> > which has short text alternatives, long descriptions, or captions). In
> > cases where the alternative content has different dimensions than the
> > original content, the user has the option to specify how the
> > layout/reflow of the document should be handled. (Level A).
> > 
> > 3.1.2 Configurable Default Rendering: The user has a global option to
> > specify which types of alternative content by default and, in cases
> > where the alternative content has different dimensions than the
> > original content, how the layout/reflow of the document should be
> > handled. (Level A)
> > 
> > 3.1.3 Browse and Render: The user can browse the alternatives, switch
> > between them, and render them according to the following (Level A):
> > 
> >    1. synchronized alternatives for time-based media (e.g., captions,
> > audio descriptions, sign language) can be rendered at the same time as
> > their associated audio tracks and visual tracks, and
> >    2. non-synchronized alternatives (e.g., short text alternatives,
> > long descriptions) can be rendered as replacements for the original
> > rendered content.
> > 
> > 3.1.4 Rendering Alternative (Enhanced): Provide the user with the
> > global option to configure a cascade of types of alternatives to render
> > by default, in case a preferred type is unavailable. If the alternative
> > content has a different height or width, then the user agent will
> > reflow the viewport. (Level AA)
> > 
> > 3.6.1 Configure Text:  The user can globally set the following
> > characteristics of visually rendered text content, overriding any
> > specified by the author  or user agent defaults (Level A):
> > 
> >     * (a) text scale (i.e., the general size of text) ,
> >     * (b) font family, and
> >     * (c) text color (i.e., foreground and background).
> > 
> > PRINCIPLE 4. Ensure that the user interface is operable
> > 
> > 4.1.1 Keyboard Operation: All functionality can be operated via the
> > keyboard using sequential or direct keyboard commands that do not
> > require specific timings for individual keystrokes, except where the
> > underlying function requires input that depends on the path of the
> > user's movement and not just the endpoints (e.g., free hand drawing).
> > This does not forbid and should not discourage providing mouse input or
> > other input methods in addition to keyboard operation. (Level A)
> > 
> > 4.9.2 Time-Based Media Load-Only: The user has the option to load time-
> > based media content @@DEFINE@@ such that the first frame is displayed
> > (if video), but the content is not played until explicit user request.
> > (Level A)
> > 
> > 4.9.5 Playback Rate Adjustment for Prerecorded Content: The user can
> > adjust the playback rate of prerecorded time-based media content, such
> > that all of the following are true (Level A):
> > 
> >     * The user can adjust the playback rate of the time-based media
> > tracks to between 50% and 250% of real time.
> >     * Speech whose playback rate has been adjusted by the user
> > maintains pitch in order to limit degradation of the speech quality.
> >     * Audio and video tracks remain synchronized across this required
> > range of playback rates.
> >     * The user agent provides a function that resets the playback rate
> > to normal (100%).
> > 
> > 4.9.6 Stop/Pause/Resume Multimedia: The user can stop, pause, and
> > resume rendered audio and animation content (including video and
> > animated images) that last three or more seconds at their default
> > playback rate. (Level A)
> > 
> > 4.9.6 Navigate Multimedia: The user can navigate along the timebase
> > using a continuous scale, and by relative time units within rendered
> > audio and animations (including video and animated images) that last
> > three or more seconds at their default playback rate. (Level A)
> > 
> > 4.9.7 Semantic Navigation of Time-Based Media. The user can navigate by
> > semantic structure within the time-based media, such as by chapters or
> > scenes, if present in the media (AA).
> > 
> > 4.9.8 Track Enable/Disable of Time-Based Media. During time-based media
> > playback, the user can determine which tracks are available and select
> > or deselect tracks. These selections may override global default
> > settings for captions, audio descriptions, etc.
> > 
> > 
> > 
> > 4.9.9 Sizing Playback Viewport: User has the ability to adjust the size
> > of the time-based media up to the full height or width of the
> > containing viewport, with the ability to preserve aspect ratio and to
> > adjust the size of the playback viewport to avoid cropping, within the
> > scaling limitations imposed by the media itself. (Level AA)
> > 
> > 4.9.10 Scale and position alternative media tracks. User has ability to
> > scale and position alternative media tracks independent of base video.
> > (Level AAA)
> > 
> > 4.9.11 Adjust Playback Contrast and Brightness. User has ability to
> > control the contrast and brightness of the content within the playback
> > viewport.
> > 
> > 1. http://www.w3.org/WAI/UA/2010/ED-UAAG20-20100430/
> > 2. http://www.w3.org/WAI/UA/2010/ED-IMPLEMENTING-UAAG20-20100430/
> > 
> > Jim Allan, Accessibility Coordinator & Webmaster
> > Texas School for the Blind and Visually Impaired
> > 1100 W. 45th St., Austin, Texas 78756
> > voice 512.206.9315    fax: 512.206.9264  http://www.tsbvi.edu/
> > "We shape our tools and thereafter our tools shape us." McLuhan, 1964
> > 
> 

-- 

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 Tuesday, 18 May 2010 23:09:33 GMT

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