- From: Ian Jacobs <ij@w3.org>
- Date: Thu, 22 Jun 2000 15:38:41 -0400
- To: w3c-wai-ua@w3.org
22 June 2000 UA Guidelines Teleconference
Present:
Ian Jacobs (Chair/Scribe)
Harvey Bingham
Kitch Barnicle
Eric Hansen
Dick Brown
Gregory Rosmaita
Tim Lacy
Charles McCathieNevile
Mickey Quenzer
David Poehlman
Regrets:
Jon Gunderson
Mark Novak
Jim Allan
Next meeting: 29 June.
Regrets: Eric (probably for next month), Jon, Kitch
Agenda [1]
[1]
http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0505.html
0) Review of action items:
TL: I talked to Rob Rylea about independent volume
control of audio sources. He said, that depends on
what software is configured to be the default player.
For IE, windows media player typically used.
IJ: Could windows media player be used for each source of
sound?
TL: You can choose the player independently of the default.
I don't know what happens when you have several media
players going at once.
(New) Action GR: Pursue speech synth ranges for other
properties than speech rate.
2) PR#287: Proposed clarification to checkpoints 3.3, 3.5, 3.6
http://cmos-eng.rehab.uiuc.edu/ua-issues/issues-linear.html#287
In particular, this proposal:
http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0496.html
Refer also to HB's proposed modification:
http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0504.html
GR: I think we want to separate content that is blinking/marquee.
Red flag: is this on a piece-by-piece basis or globally.
HB: Is it consistent with marquee that it always moves in a
reading direction?
GR: Not sure for non-standard markup.
TL: The MARQUEE element supports directionality.
IJ: I think the issue was movement, do we need the fine
control?
EH: But if you freeze everything, it would make it hard
to interact with the page. Presumably, a global control
would freeze all video in the document.
KB: Is restart the same as removing pause?
EH: "resume"?
Consensus on "resume".
HB: In SMIL, you can jump to anchors in video.
IJ: One proposal is to treat video and audio
individually, but animations and blinking
globally. But of course, you could treat
synchronized components as a unit.
EH: Isn't the focus generally on one particular
video, rather than multiple video?
KB: We've talked about a video track of sign
language.
EH: But presumably they would be linked so that
they could be controlled in sync.
KB: Yes, in that situation. But you could imagine
three sports matches on the screen at the
same time.
EH: It's common to find several animated graphics
operating independently on the screen.
IJ: Maybe we can make a distinction based on
"importance". Video seems to be more
important in general.
EH: One way to distinguish animations and
video (without considering importance)
is to say "start, stop, pause, and resume
multimedia presentations and audio
presentations". I'm not sure whether
blinking content should be considered separately.
That way, in the future if the dividing line
between animations and video blurs, we're
covered. This may be a case where global
and independent control are useful.
IJ: Like global and independent volume control.
TL: (Back on the multimedia question):
I have three players operating indendently on
separate feeds, and I can control them
separately. If you had a Web page with 2-3
embedded AVIs, and they were set to play
on load and to use a plug-in, it should work.
IJ: That's great, except that some sources may
be not handled by the UA (but other software).
TL: Also, they can run asychronously. Suppose you
had 2 AVIs using HTML+Time to display dynamically
changing captions. What would happen: as each
caption changes independent of each other, it would
get a focus event, meaning that the screen reader
would jump between them.
GR: When HPR first came out, this was a problem - two
instance of screen readers.
GR: With pure audio, UI is spoken by screen reader and
AVIs are left alone.
DP: How do you read the text in a SMIL presentation.
MQ: It depends on the browser. WebSpeak has problems with
this (you can't have an audio stream going and browse
at the same time). With Jaws and IE5, the access program
is monitoring the UI that got spawned by the presentation.
The browser would still be active, but if it didn't have
focus, you wouldn't know what was going on.
GR: Also UI issues - when I was listening to LPPlayer with
Jaws.
IJ: How usable is the interface where there are three
media players going at once?
TL: About the same as a picture in a picture on a TV.
There could be some utility to this.
TL: What about, if you have 3 streams, you need to be
able to turn two off?
IJ: That sounds like it's not good enough: you may need
to hear all of them at once, at different levels.
IJ: I think that default level should be global, and
that control is available individually (on a
page-by-page basis).
IJ: Any objections to the proposal:
http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0434.html
1) Allow the user to configure the global audio volume
(including silent).
Note: Do this at the OS level or the assistive technology
level.
2) Allow the user to control the volume of audio sources
independently.
Delete 3.2, 3.4
CMN: How far to you have to be able to turn up the volume
before it becomes a hardware problem?
IJ: I would say that applicability kicks in at that point.
Consensus: Adopt this proposal.
Action IJ: Incorporate in the next draft.
EH: For the other proposal:
a) Handle multimedia presentation, audio presentation (audio
only) and stand-alone visual track.
b) For all of those, advance, rewind, start, stop, pause, and
resume.
c) For blinking content, one idea was to be able to override
the blinking (perhaps toggling between on and off state).
IJ: Is this pause and resume?
EH: If it's pause, is the content off or on?
IJ: For me, the minimal requirement is stop and have
apparent content. The ability to restart is not
as apparent.
GR: Are we talking about just text?
IJ: No, I think content in general.
EH: Is blinking content either a standalone visual track?
If so, it falls under category "b". If we're talking
about a specific case for HTML, we could limit ourselves
to the blinking text case.
/* Mickey drops off */
EH: Maybe, if we have fine-level control for the
items in group "a", maybe we can concentrate on
blinking text only.
IJ: Your proposal drops the blinking image case.
GR: How do UAs know when something is animated?
CMN: The image contains some control code. Rollovers
are done with javascript. Browsers allow you
to stop gif animations. There's no technical
barrier to having that as a default behavior.
IJ: The requirement to step-through animation is
P1 for access to all content.
Proposal:
1) Advance, rewind, start, stop, pause, and resume
multimedia presentation, audio presentation (audio
only) and stand-alone visual track.
2) Freeze blinking text and render statically.
GR: What about scrolling text?
IJ: Is that an animation?
EH: There are cases where an animation looks exactly
like text. Do blinking or scrolling text constitute
animations?
HB: Captioning would be another example.
IJ: Yes, how do captions fit into this?
EH: Maybe we don't need a special checkpoint for text.
Maybe mention this in a note: include this
as a "stand-alone" visual track.
GR: I think there's a distinction between visual
track and text, because you could want all text
at once.
EH: Then we would exclude moving text from #1
and indicate that it's covered in #2.
Refer to Eric's background on multimedia:
http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0503.html
Action IJ: Propose multimedia definitions to the list
to define borders of these proposed checkpoints.
EH: One question: Should a standalone visual track be
considered a special case of a multimedia presentation?
EH: One idea: allow the user to configure the UA for
consent before playing an auditory track.
IJ: Why is this different from blinking or moving content?
I could see this being done globally, but I wouldn't want
to have to confirm the playing of each source.
CMN: (On the question of what the viewport is for sound):
Does real stereo mean different viewports? I think the
idea of one speaker is insufficient.
EH: We have tracks, channels, viewports, and speakers.
CMN: We address issues like positioning of multiple viewports
and synchronization of viewports. When you have multiple
channels at once, you need to be able to configure how
you receive those channels.
EH: Do we have checkpoints that cover GR's requirements
already? One requirement would be "Be able to configure
the UA to prompt before opening an additional viewport."
Wouldn't this cover the case of launching an application
that plays audio? Or maybe we go back to what I suggested
earlier: promt the user before playing a new audio
presentation
or standalone audio. You could have a similar checkpoint
for video as well. Should this be a universal requirement:
before you start a presentation, you should be able
to configure the UA to prompt before opening.
IJ: I don't want to be prompted for each loaded image.
GR: I continue to return to the analogy of inadvertent
submission of forms.
IJ: I agree that the "on/off" requirements haven't been
clear about whether this means globally or on
a source-by-source basis.
EH: What about 4.15: control of focus changes: Would this
cover loading of audio?
Action GR: Re-examine the orientation checkpoints and
see whether they can be clarified to account for control
of rendering of audio (and possibly other content) on load.
EH: We're focusing on audio on-load. What about prompting
for individual graphics or animations?
DP: I'm not sure what the accessibility issue would be
for other content types. I can imagine cases where
we might want to load background images and sometimes
we might not.
GR: Turning images on or off is a conscious decision not
to load images. I don't think you should be prompted
on an image-by-image basis. I'm more concerned about
those things that are not static.
--
Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs
Tel: +1 831 457-2842
Cell: +1 917 450-8783
Received on Thursday, 22 June 2000 15:38:48 UTC