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Re: Question regarding animation requirements in UAAG 1.0

From: Charles McCathieNevile <charles@w3.org>
Date: Thu, 25 Jan 2001 08:46:24 -0500 (EST)
To: David Poehlman <poehlman1@home.com>
cc: Ian Jacobs <ij@w3.org>, WAI UA group <w3c-wai-ua@w3.org>
Message-ID: <Pine.LNX.4.30.0101250843130.9651-100000@tux.w3.org>
There is a risk that changing the speed, even while respecting the
synchronisation, will make one component harder or impossible to understand.
We should note  that possibility. But that is the price to pay for getting
another track better understood, although it might end up being two passes to
get the whole message (this is better than two passes that end up with no
ability to understand it).


On Thu, 25 Jan 2001, David Poehlman wrote:

  I have a question and a comment:
  question: is there an example of a "stylistic effect"?
  comment.  With pitch supression as it is done through speech synthesis
  today, the audio can be much slower than 80 percent and still be
  understood.  I can get my accent to comprehend quite low rates for
  instance at 50 percent.  if the voice is pre-recorded and synched then
  of course, at low rates much like a recording of any kind, it falls
  off the low end of the comprehensibility scale.  A further note.  many
  animations are accompanied by synthesized speech such as in ms agent.
  The characters move and speak but we currently have no control over
  the motion or the audio.

  ----- Original Message -----
  From: "Ian Jacobs" <ij@w3.org>
  To: <clilley@w3.org>
  Cc: <w3c-wai-ua@w3.org>
  Sent: January 24, 2001 2:21 PM
  Subject: Question regarding animation requirements in UAAG 1.0

  Hi Chris,

  In the 16 Jan 2001 draft of the User Agent
  Accessibility Guidelines 1.0 [1], there are two checkpoints
  that involve control of animations:

   4.4 Allow the user to slow the presentation rate of audio,
   video and animations. For a visual track, provide at least
   one setting between 40% and 60% of the original speed. For a
   prerecorded audio track including audio-only presentations,
   provide at least one setting between 75% and 80% of the
   original speed. When the user agent allows the user to slow
   the visual track of a synchronized multimedia presentation
   to between 100% and 80% of its original speed, synchronize
   the visual and audio tracks. Below 80%, the user agent is
   not required to render the audio track. The user agent is
   not required to satisfy this checkpoint for audio, video and
   animations whose recognized role is to create a purely
   stylistic effect. [Priority 1]

   4.5 Allow the user to stop, pause, resume, fast advance, and
   fast reverse audio, video, and animations that last three or
   more seconds at their default playback rate.  The user agent
   is not required to satisfy this checkpoint for audio, video
   and animations whose recognized role is to create a purely
   stylistic effect. [Priority 1]

  We are currently discussing whether these requirements
  should apply to any type of animation (does that make sense?)
  or format used to create animation (markup, script, image format,
  style sheet). Note: We have a general "exemption"
  clause in our document (for the purposes of conformance) that
  says that if the format doesn't enable the UA to recognize or
  control the animation effect, then the requirements don't apply.

  So my questions are:

  1) Do you think that there are any classes of animation or
     animation formats for which these requirements don't make

  2) Do you have a good definition of "animation" handy?

  Thanks for any input,

   - Ian

  [1] http://www.w3.org/WAI/UA/WD-UAAG10-20010116

  Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
  Tel:                         +1 831 457-2842
  Cell:                        +1 917 450-8783

Charles McCathieNevile    http://www.w3.org/People/Charles  phone: +61 409 134 136
W3C Web Accessibility Initiative     http://www.w3.org/WAI    fax: +1 617 258 5999
Location: I-cubed, 110 Victoria Street, Carlton VIC 3053, Australia
(or W3C INRIA, Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France)
Received on Thursday, 25 January 2001 08:49:26 UTC

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