- 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>
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).
Chaals
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
sense?
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