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Action-1044 Review media a11y requirements for 1.1.6 resize, reposition of media

From: Jim Allan <jimallan@tsbvi.edu>
Date: Thu, 18 Dec 2014 10:49:33 -0600
Message-ID: <CA+=z1W=PVN23m6Huyts6Tk73U7Zcoa9UXkSPukndKjVHi60sMg@mail.gmail.com>
To: WAI-ua <w3c-wai-ua@w3.org>
reviewed http://www.w3.org/TR/media-accessibility-reqs/ for correlation to
1.1.6 - they have it covered.
1.1.6 below for reference, and appropriate checklist items listed below for
reference.
Note the Media Accessibility requirements have outdated references to
UAAG20, I am compiling a list and will forward it to them.

Jim
1.1.6 Allow Resize and Reposition of Time-based Media Alternatives:

The user can configure recognized
<http://w3c.github.io/UAAG/UAAG20/#def-recognize> alternative content for
time-based media (e.g. captions, sign language video) as follows:
(Level AAA)

   - *Resize:* The user can resize alternative content for time-based media
   to at least 50% of the size of the top-level viewports
   <http://w3c.github.io/UAAG/UAAG20/#def-viewport-toplevel>.
   - *Reposition:* The user can reposition alternative content for
   time-based media to two or more of the following: above, below, to the
   right, to the left, and overlapping the primary time-based media.


   - *Note 1:* Depending on the screen area available, the display of the
   primary time-based media may need to be reduced in size or hidden to meet
   this requirement.
   - *Note 2:* Implementation may involve displaying alternative content
   for time-based media in a separate viewport, but this is not required.


media guideline correlates
*[IC-2]* Support a rich set of native controls for media operation,
including but not limited to play, pause, stop, jump to beginning, jump to
end, scale player size (up to full screen), adjust volume, mute, captions
on/off, descriptions on/off, selection of audio language, selection of
caption language, selection of audio description language, location of
captions, size of captions, video contrast/brightness, playback rate,
content navigation on same level (next/prev) and between levels (up/down)
etc. This is also a particularly important requirement on mobile devices or
devices without a keyboard.

*[VP-1]* It must be possible to deal with three different cases for the
relation between the viewport size, the position of media and of
alternative content:

   1. the alternative content's extent is specified in relation to the
   media viewport (e.g., picture-in-picture video, lower-third captions)
   2. the alternative content has its own independent extent, but is
   positioned in relation to the media viewport (e.g., captions above the
   audio, sign-language video above the audio, navigation points below the
   controls)
   3. the alternative content has its own independent extent and doesn't
   need to be rendered in any relation to the media viewport (e.g., text
   transcripts)

​*[VP-3]* Provide the user with 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. (UAAG 2.0 1.8.9)

*[CC-5]* Support positioning in all parts of the screen - either inside the
media viewport but also possibly in a determined space next to the media
viewport. This is particularly important when multiple captions are on
screen at the same time and relate to different speakers, or when
in-picture text is avoided.

*[CC-15]* Support positioning such that the lowest line of captions appears
at least 1/12 of the total screen height above the bottom of the screen,
when rendered as text in a right-to-left or left-to-right language.​

-- 
[image: http://www.tsbvi.edu] <http://www.tsbvi.edu>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
Received on Thursday, 18 December 2014 16:50:19 UTC

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