RE: The mandatory constraint is a footgun

Now I'm really confused.  What do you mean by 'constraints being initial settings"?  In the current draft, they can be applied at any point.  The initial setting (i.e. before the app applies any constraints) is chosen by the UA, and can be anything it wants (within the range of the capabilities it supports.)

- Jim

-----Original Message-----
From: Martin Thomson [mailto:martin.thomson@gmail.com] 
Sent: Wednesday, November 13, 2013 12:57 PM
To: Jan-Ivar Bruaroey
Cc: public-media-capture@w3.org
Subject: Re: The mandatory constraint is a footgun

On 11 November 2013 22:04, Jan-Ivar Bruaroey <jib@mozilla.com> wrote:
> I've implemented a strict interpretation of the spec's mandatory 
> constraint that treats unknown keys as unsupported, I've tried it, and 
> I think it is wrong.

I tend to agree.

We've had this discussion several times. Usually it's when someone has sat down and carefully thought out the real impact that this has on users and applications.

I'm going to go out on a limb and make a bit of a radical suggestion.
The following functions are sufficient:

 * Enumerate devices with quasi-stable identifiers.
 * Select a specific device.
 * Ask the browser to select a device.
 * Apply settings to MediaStreamTrack instances.
 * Get the set of supported settings, and their acceptable ranges.
 * The overconstrained event (i.e., the settings couldn't be applied event).

I can't think of a good use case that isn't supported by that set of features.  If we think of constraints as initial settings, I think that we could make them a whole lot simpler.

Though I don't like being contrary when your logic is so rational, I have concluded that it's the mandatory set that we keep, and the optional parts that are removed.  Though I solidly agree about the part where you point out that unsupported/unknown attributes have to be ignored.

Received on Wednesday, 13 November 2013 18:01:20 UTC