Re: [mediacapture-main] A practical algorithm for constraint resolution needs to be described.

Firefox 38 implements the ideal algorithm, and 39 [internally 
treats](http://mxr.mozilla.org/mozilla-central/source/dom/media/webrtc/MediaEngineCameraVideoSource.cpp?rev=ce72894838de&mark=119-120#115)
 width == 0, height == 0 or frameRate == 0  on the *capability* (not 
the constraint) as "can do any" i.e. orthogonal.

Basically, if a capability is zero ("can do any") then it contributes 
zero to fitness distance.

While no real cameras provide zero (the low-level gips stack doesn't 
allow it), this was helpful for internal screensharing devices which 
put 0,0,0 to survive the ideal algorithm.

This should also be useful on OSX where we feed the ideal algorithm 
fake hardcoded devices. These are hardcoded to 30 fps in Firefox 38, 
but I suspect OSX can return any framerate, so zero FPS might work 
better there.

-- 
GitHub Notif of comment by jan-ivar
See 
https://github.com/w3c/mediacapture-main/issues/118#issuecomment-96037180

Received on Friday, 24 April 2015 19:04:24 UTC