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Re: Rationalizing new/start/end/mute/unmute/enabled/disabled

From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
Date: Tue, 26 Mar 2013 18:49:45 +0000
To: Martin Thomson <martin.thomson@gmail.com>
CC: "public-media-capture@w3.org" <public-media-capture@w3.org>
Message-ID: <1447FA0C20ED5147A1AA0EF02890A64B0C8E88@ESESSMB209.ericsson.se>


On 3/26/13 5:07 PM, "Martin Thomson" <martin.thomson@gmail.com> wrote:

>On 26 March 2013 02:38, Stefan Håkansson LK
><stefan.lk.hakansson@ericsson.com> wrote:
>> (Commenting on the entire "Rendering" section)
>>
>> I agree to that we need to describe in more detail how MediaStream's
>> interact with media (audio and video) elements. Jim took a stab at it
>>last
>> year, but it is time for an update. Audio and video are also different
>>in
>> that you can render only one video track in a media element, but mix all
>> audio tracks.
>>
>> However, I want to point out that the "resource fetch algorithm" of the
>>html
>> 5 Candidate rec
>> 
>>(http://www.w3.org/TR/html5/embedded-content-0.html#concept-media-load-re
>>source)
>> already describes this quite detailed. I think we might get by with
>> referring to that, but clarifying how certain things apply to
>>MediaStreams.
>
>I read through that section and it doesn't really say anything about
>what I was getting at: which tracks affect what is rendered.  Making
>certain that any work we do is consistent with HTML 5 is one thing,
>but we can't rely on HTML to describe this particular characteristic.

I read step 11, 

"If either the media resource or the address of the current media resource
indicate a particular set of audio or video tracks to enable, then the
selected audio tracks must be enabled in the element's audioTracks object,
and, of the selected video tracks, the one that is listed first in the
element's videoTracks object must be selected."

as telling pretty detailed what tracks that should be rendered. What
remains to be be specced is IMO:
* That each audio track that is enabled "indicates" that it should be
enabled in the media element's audioTrackList - the enabled ones are
rendered (mixed)
* Which video track, if more than one is enabled at load time, should be
put as "selected" in the media elements videoTrackList - the selected one
is rendered
Received on Tuesday, 26 March 2013 18:50:11 UTC

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