W3C home > Mailing lists > Public > public-media-capture@w3.org > June 2012

Grabbing exactly one camera (Re: Implementation suggestions)

From: Harald Alvestrand <harald@alvestrand.no>
Date: Thu, 07 Jun 2012 13:46:43 +0200
Message-ID: <4FD094A3.4090203@alvestrand.no>
To: public-media-capture@w3.org
On 06/07/2012 08:23 AM, Anant Narayanan wrote:
> Hi Stefan,
>
> On 06/05/2012 11:45 PM, Stefan Hakansson LK wrote:
>
>> * Should there a way for the application to indicate that it wants only
>> one audio and one video track when calling getUserMedia? If this was
>> possible, the browser could then make the selections "exclusive-or" when
>> set, "and" when not set.
>
> I think there should be a normative way for non-trusted applications 
> to specify a limited set of constraints to do this kind of thing. 
> Let's discuss some proposals and see if we can reach some consensus.
I'm starting to like Stefan's "let's grab'em all" approach for dealing 
with multiple cameras... what if we define some constraints?

Video:<Min/Max>Tracks

so that

getUserMedia({video: {mandatory [{MinTracks: 2}]}, audio:true}}, ....)

would give a MediaStream with at least 2 video tracks and at least one 
audio track, while

getUserMedia({video: {mandatory [{MaxTracks: 1}]}, audio:true}}, ....)

would give a MediaStream guaranteed to have no more than one video track 
(and give a hint to the UI for approval to make camera selections exclusive)

That would give us the expressive power without messing up the 
interfaces for the simple case.

            Harald
Received on Thursday, 7 June 2012 11:47:24 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:24:35 UTC