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RE: Questions regarding animation requirements in UAAG 1.0

From: Patrick Schmitz <pschmitz@microsoft.com>
Date: Tue, 27 Feb 2001 09:17:31 -0800
Message-ID: <6CAC6551F8C10F4C9EC0CF34132F2AAE4FCBDC@red-msg-07.redmond.corp.microsoft.com>
To: "Ian Jacobs" <ij@w3.org>, "Cohen, Aaron M" <aaron.m.cohen@intel.com>
Cc: <clilley@w3.org>, <w3c-wai-ua@w3.org>, <dd@w3.org>, <asgilman@iamdigex.net>
You can do all this right now in IE 5.5.

Here is a pointer to my personal demo page (only looks like much in IE

and for a demo of speed, see the orbit demo (first one on the page

This includes binding to buttons (no script) for reverse, fast forward,
slow forward and volume control (not that there is no script used in
this animation, even for the button controls). Everything is wired
declaratively. Note that the midi audio plays at all forward rates, at
the correct speed but no pitch corrected. I have not yet found an audio
or video decoder commonly used on the web that behaves well with reverse
speeds (but the SMIL 2 model includes rules for graceful degradation in
these cases).

Even if you do not have IE 5.5 and so cannot play the animation, you can
fetch it into the HTML browser of your choice and then view the source.
I would be happy to answer further questions.

If you are interested in speed animations in particular, we should talk
about the model IE implemented, which is a VTR model rather than a pure
DOM model (I can explain the differences if you care).

Hope this helps - Patrick

> -----Original Message-----
> From: Ian Jacobs [mailto:ij@w3.org]
> Sent: Tuesday, February 27, 2001 9:02 AM
> To: Cohen, Aaron M
> Cc: Patrick Schmitz; clilley@w3.org; w3c-wai-ua@w3.org; dd@w3.org;
> asgilman@iamdigex.net
> Subject: Re: Questions regarding animation requirements in UAAG 1.0
> Hello,
> I ran into Aaron here at the Sonesta hotel, and pursued the
> question of animation control for a few minutes. Aaron pointed
> me to the following resources:
> 1) The 'speed' attribute is defined in section 11.1.3 of the 
>    time manipulation module of SMIL 2.0 [1].
>    The attribute defines the playback speed of element time.
>    Values can be negative, for playback in reverse. This suggests
>    that fast forward and reverse are also possible.
> 2) IE 5.5 may already implement this attribute (not absolutely sure, 
>    but they do implement the accelerate and decelerate attributes).
> 3) One could specify "speed=.5" on the root time container element
>    and slow down a whole document by half. Or one could do this on
>    an element-by-element basis.
> 4) I'm not aware of players that let you do this today through the
>    user interface.
> So, this is starting to suggest to me our requirements for animation
> control are covered by the SMIL 2.0 spec.
>  - Ian
> [1]
> http://www.w3.org/TR/2000/WD-smil20-20000921/smil-timemanip.ht

Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
Tel:                         +1 831 457-2842
Cell:                        +1 917 450-8783
Received on Tuesday, 27 February 2001 12:33:36 UTC

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