W3C home > Mailing lists > Public > public-media-capture@w3.org > April 2013

Re: Overconstrained

From: Harald Alvestrand <harald@alvestrand.no>
Date: Wed, 03 Apr 2013 17:30:11 +0200
Message-ID: <515C4B03.5000308@alvestrand.no>
To: public-media-capture@w3.org
On 04/03/2013 04:37 PM, Randell Jesup wrote:
> On 3/27/2013 1:20 PM, Martin Thomson wrote:
>> In a large proportion of the remainder, the user will be the one
>> deciding which input device to use.  Most likely, they will have done
>> so in the OS or chrome beforehand.
>>
>> For users, the single most important factor in determining which
>> camera to use will be where it is pointed.  Applications too. In both
>> cases, this will probably be to the exclusion of all other factors.
>>
>> In the vanishingly small subset of cases where the above is not
>> sufficient, it is not a problem for an application to ask for another
>> camera.  I'm willing to bet that those cases are going to be
>> specialized applications with better-informed users that are
>> sufficiently motivated and informed to comply.
>>
>> Facing therefore becomes the most important constraint.  The sourceId
>> constraint allows for stability of selection over time, especially for
>> those cases where a default doesn't work.
>
> I'm 100% in agreement on this.  As I said at the Interim (and others 
> did too, including Martin), the most (and virtually only) interesting 
> constraint for a user is "what is the camera pointed at".  Now for 
> microphones, the question gets more interesting (attached mic on 
> camera vs secondary mic), but once again it's a question of "where is 
> the mic" not "what is the mic".
I must be unusual. I usually rush into a hangout, go "oh crap, it's the 
built-in camera again", dig out the better camera, plug it in, and change.

My cameras all point in the same direction.
>
> (Browser) UI's where the user selects cameras with images of what they 
> can see have an advantage here.  For microphones, there are similar 
> ideas possible.
>
> Setting camera "constraints" (really settings) after acquisition is a 
> separate question, but on getUserMedia() I'm wholly on-board with 
> eliminating constraints (outside of SourceID perhaps initial 
> *settings* (like preferred resolution -- not selection criteria)), or 
> at most using them to order choices/provide feedback to the user (and 
> I don't think there's enough benefit to the user to do that).
>
Received on Wednesday, 3 April 2013 15:30:45 UTC

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