Re: Proposal: Constraints as dictionaries

On 21 November 2013 08:55, Jan-Ivar Bruaroey <jib@mozilla.com> wrote:
> It is my understanding that video and audio constraints share the same
> namespace. From
> http://dev.w3.org/2011/webrtc/editor/getusermedia.html#methods-3 :

Sharing a namespace doesn't mean that it always makes sense to mix semantics.

The point I was making was that your example at least was just (assuming C):

   navigator.getUserMedia([{width: 1920}]);

As opposed to:

  navigator.getUserMedia({video: [{width:1920}]});  // wow, cool helmet }]}:)|-<

I don't think that we want to lose the whole ability to say whether
you want audio or video.  In particular, collapsing the two makes
things like sourceId impossible to specify (i.e., { audio: true,
video: true, sourceId: "12341234234"} never successfully resolves).

>  "For each constraint key-value pair in the "optional" sequence of the
> constraints that are for the current media type, in order,"
>
> (btw, that is section 9.1.1. Should I be alarmed?)
>
> So this shouldn't be a problem.

That is not a problem, though I originally thought it was.  I missed
that that text on the first, second and even third passes through the
algorithm.  It needs calling out.  Editors alert.  (Note that this
doesn't apply for mandatory constraints, so there is a distinct lack
of symmetry.)

> My takeaway from your point is that this requires browsers to implement a
> constraint for all media types it applies to, at the same time. I'm OK with
> that.

That wasn't really the point of my email.  So I'm surprised at the
conclusion, though not displeased :)

My point was actually to try to find a way of getting access to gUM
capabilities a little more cleanly.  But the only idea I have turns on
the little light first, which is suboptimal.

> By the same argument we should use double everywhere. Are you saying we
> should use double everywhere?

For constraints, yes.  If we need a string range or some other such
construct, we can build it when it is needed.  DoubleRange and
StringSet seem sufficient for now.

Received on Thursday, 21 November 2013 17:29:25 UTC