- From: Harald Alvestrand <harald@alvestrand.no>
- Date: Thu, 15 May 2014 15:39:02 +0200
- To: public-media-capture@w3.org
On 05/15/2014 03:36 PM, Jim Barnett wrote: > In alternative A, won't the unknown mandatory constraints fail in gUM > before the permissions prompt is reached? Would the UA ever prompt > the user for devices with properties that it doesn't understand? I ignored the UA's possible prompting in the descriptions; the "Sorry" messages would come from the error handlers in the Javascript, handling the failure callback from getUserMedia. > On 5/15/2014 4:09 AM, Harald Alvestrand wrote: >> 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 13:39:32 UTC