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Re: New version of constrainable section of getusermedia

From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
Date: Mon, 3 Feb 2014 09:31:11 +0000
To: "Cullen Jennings (fluffy)" <fluffy@cisco.com>, "public-media-capture@w3.org" <public-media-capture@w3.org>, "public-webrtc@w3.org" <public-webrtc@w3.org>
Message-ID: <1447FA0C20ED5147A1AA0EF02890A64B1CF485B5@ESESSMB209.ericsson.se>
Many thanks (to everyone that contributed) for getting this put together.

I think it reflects well the functionality that people have been asking
for constraints (and that we've been discussing over and over again, and
come back to there is a need for), such as:
* enable selection of input devices
* enable "must" and "preferred" operation modes
* inform the app if a "must" can't be met - both at application time and
at run time
* inform the app if it tries to influence something the UA does not

Reading through, I have a couple of questions:

Is there a need for queuing? applyConstraints() has callbacks; could
there be a situation when applyConstraints() immediately followed by
getConstraints() would get the old ones (not the ones just applied)?

Section 11.1.2, step 6: I'm not sure about the value of adding only the
optional ConstraintSets that can be satisfied to newConstraints. Can't
the optional constraints be seen as a wish list that the UA (together
with the underlying system) will make its best to meet (in order), but
no guarantees? And, even if a ConstraintSet can't be met right at
application time, it could be possible shortly afterwards (and vice
versa: something can happen at runtime meaning that an optional
ConstraintSet that could be met at application time can no longer be
met). If the application want to know the status at runtime it has to
check the current Settings.

Section 11.1.2, last step (7) in algo, there is a not ending "...
satisfy the current set of constraints." 'set of constraints' is not
well defined, should it be 'Constraints in effect' instead? Further, is
it not so that the UA can modify any value at any time to any value,
_but_ if the modification renders a value go outside the boundaries set
up by the mandatory ConstraintSet it should fire the "overconstrained"


On 2014-02-01 02:06, Cullen Jennings (fluffy) wrote:
> There is a new version of the draft at 
> http://dev.w3.org/2011/webrtc/editor/archives/20140130/getusermedia.html
> We deleted most of it text in it. 
> Don’t Panic 
> We deleted all the sections except section 11 which is the Constrainable interface. We just wanted to get the new Constrainable section out for everyone to read and discuss. This is the generic interface that deals with constraints. If people agree with this, we can go make all the changes to the rest of the document to line up with this interface and then publish the full draft. 
> Thanks,  <The editors> 
> ( And thanks to Jim who contributed a bunch of the text for this section )
> PS - Since this interface is equally important to webrtc and getUserMedia, I have taken the liberty to send it both lists. 
Received on Monday, 3 February 2014 09:31:37 UTC

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