Re: getCapabilities() as both static and object method?

On 05/15/2014 02:35 AM, Jan-Ivar Bruaroey wrote:
> On 5/13/14 3:41 AM, Harald Alvestrand wrote:
>> The need as identified  is to know what constraints are recognized by
>> the platform before calling getUserMedia (that is, before we have any
>> instances to call the function on).
>
> Would this method return just the constraint names understood by this 
> UA or actual values?

If it has the same syntax as the current one, names and values.

>
> If the latter, what values? Some union (or intersection?) of all 
> camera capabilities on a user's system?

My thinking: Union of capabilities - the range of values that it doesn't 
make sense to go outside.
You will have corner cases (max 320x200 camera, HD camera that can't go 
below 640x480), but I can't think of anything that makes more sense than 
"union".

>
> getUserMedia is prescriptive, and unknown mandatory constraints fail, 
> so I don't see why we need this method.

Yes, it's possible to do this by probing.
However, I can see three different dialogues resulting, only one of 
which I like:


--- Alternative A, mandatory constraints

   [ Grab the camera! ]
     [x] Use the depth channel
     [x] Use the IR channel
     [x] Use the front camera

---- hit the button

    Sorry, I don't understand what "IR channel" means

---- swear, unmark, hit the button

    Sorry, I don't understand what "depth channel" means

--- swear, unmark, hit the button

    Sorry, I don't have any "front" camera.

--- with the patience of an angel, remove the last checkbox and hit the 
button again

   Welcome! Here's your camera!

--- Alternative B, optional constraints

   [ Grab the camera! ]
     [x] Use the depth channel
     [x] Use the IR channel
     [x] Use the front camera

--- hit the button
    Welcome! Here's your camera!
    I know you asked for "front", "IR" and "depth", but it seems that 
this camera is facing in some
    random direction, and I don't understand the rest of your question, 
so I ignored it.

--- Alternative C, pre-filtering

   [ Grab the camera! ]

--- hit the button

    Welcome! Here's your camera!


>
> .: Jan-Ivar :.
>

Received on Thursday, 15 May 2014 08:10:12 UTC