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ACTION-460 part 2

From: Jim Allan <jimallan@tsbvi.edu>
Date: Thu, 28 Oct 2010 12:01:01 -0500
Message-ID: <AANLkTi=jgw6Bjwai5CRyrV3sbm3jqqrMJVGcD_a2a7Rk@mail.gmail.com>
To: WAI-ua <w3c-wai-ua@w3.org>
ACTION-460 	 jallan to review CC2,3,4

cc2 allow erasures, i.e. times when no text cues are active
 cc3 allow gap-less cues

summary of discussion:
 It seems to me that these are also covered by our requirement that UA
implement technologies as spec'd: if the spec allows these features,
the UA has to support them.
That is, 1.4.1 Follow Specifications: Render content according to the
technology specification. This includes any accessibility features of
the technology (see Guideline 1.3). (Level A)
no difference in gap-less presentation and erasures as far as markup
is concerned. the gap-less or erasures is handled by the player.
 caption playback presentation is akin to internal UA stylesheet (that
up until recently user was not able to change)(it is currently present
and operable, but the author/user cannot change the playback
 use case, users who are slow readers will need gap-less presentation.
overriding erasures in the player
implementations - can/may be created by last call
define default rendering style (gap-less or erasures). 3.1.2
Configurable Default Rendering (at least the title)
 may fit better in 4.9, create new SC or modify 3.1.4 second sentence
 "If the alternative content has a different height or width, the user
agent will reflow the viewport." could become "If the alternative
content has a different height or width, the user agent will reflow
the viewport; if the alternative content has a longer duration, the
user can have the user agent pause the primary content to allow the
alternative content to..." ?
 Mark brings up idea that the user may want to have captions pause
until the user can finish reading them (e.g. slow braille reader or
slow visual reader).
 smil - pauses at the end of each caption element, so braille reader
can say continue after reading is complete
playback runs until caption appears, then auto-pauses until user
signals that playback shoudl resume.
 persistence of transient events (hyper links, gapless), have an event
persist until something replaces it. or the window to respond to a
 use examples for slow reader, gapless presentation, braille reader
pause after caption
describes scrolling list of captions (5+ seconds) at CSUN

Proposal NEW SC
 4.9.12 Persistence of time-based media content. The UA should provide
a mechanism to allow time-based content to persist beyond the
author-specified duration. (AA or AAA)

 Intent of Success Criterion 4.9.12:
 During playback of time-based media, some content, such as captions
or hyperlinked hotspots, may appear and disappear along the authored
timeline. Users, for example those with visual or learning
disabilities, may require additional time to read or interact with the
content which exceeds the authored presentation time. The UA should
provide a mechanism that allows the user extend the presentation
duration of time-based content so that it persists beyond the authored
time interval.

notes for examples
 gap-less. authored timeline - caption appears from 1-3 seconds,
another caption does not appear until 4 seconds. normally, the caption
would disappear for one second. The user can specify through some
setting that the caption stays on the screen until the next caption
replaces it.
  ex 1 gapless captions, ex 2 transient hyperlinks, ex 3 scrolling
transcript ex 4, paused caption presentation
 2. hyperlinks would persist until next caption (gapless) to give time
to click hyperlink allowing the user as much time as they need to read
a screen of captions, before they manually unpause.
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, 28 October 2010 17:01:39 UTC

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