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Re: Survey ready on Media Text Associations proposal

From: Markku Hakkinen <mhakkinen@acm.org>
Date: Fri, 5 Mar 2010 13:40:28 -0500
Message-ID: <3dcaabaf1003051040h7c8ff9efy14c7ed20f156586f@mail.gmail.com>
To: Dick Bulterman <Dick.Bulterman@cwi.nl>
Cc: Silvia Pfeiffer <silviapfeiffer1@gmail.com>, Eric Carlson <eric.carlson@apple.com>, Michael Smith <mike@w3.org>, HTML Accessibility Task Force <public-html-a11y@w3.org>
To add to Dick's SMIL example, I have taken the examples from the Text
Associations wiki [1] and coded the SMIL equivalents [2].


[1] http://www.w3.org/WAI/PF/HTML/wiki/Media_TextAssociations

[2] http://www.talkinginterfaces.org/lab/video/html5smil.html

On Fri, Mar 5, 2010 at 7:10 AM, Dick Bulterman <Dick.Bulterman@cwi.nl>wrote:

> On the track proposal, just to make sure I'm not missing something:
> Is there an implied preference order in the statements:
>  <trackgroup media="accessibility(captions:yes") >
>>>  <track src="en.srt" lang="en" enabled >
>>>  <track src="fr.srt" lang="fr" >
>>>  <track src="de.srt" lang="de" >
>>> </trackgroup>
> (In other words, the implied preference order is English, French, German.)
> Compare this to the SMIL way of doing the same thing:
>  <par>
>    <video src="..." />
>    <switch systemCaptions="on" allowReorder="yes">
>      <textstream src="en.xxx" systemLanguage="en" />
>      <textstream src="fr.xxx" systemLanguage="de" />
>      <textstream src="de.xxx" systemLanguage="de" />
>    </switch>
>  </par>
> The default behavior is that the first candidate matching a set language
> preference is used. The 'allowReorder' attribute explicitly allows a user
> agent the reorder the order of options if the user (via the UA) has
> determined that he/she prefers German over French.
> Note also that in this example, the entire <switch> is only evaluated if
> the user (agent) has determined that captions are required. Note finally
> that if the user has the language preference Dutch, no captions will play
> (since he presumably can't understand them anyway). Having a final statement
> in a <switch> without a predicate determines a result that will allows play
> if no earlier option (reodered or not) do not provide a preference match.
> Are the semantics of <trackgroup> similar? (If so, why invent something
> new; if not, are at least the SMIL semantics supported?)
> -d.
Received on Friday, 5 March 2010 18:41:01 UTC

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