- From: Jan-Ivar Bruaroey <jib@mozilla.com>
- Date: Tue, 15 Sep 2015 00:32:20 -0400
- To: Harald Alvestrand <harald@alvestrand.no>, Martin Thomson <martin.thomson@gmail.com>, "public-webrtc@w3.org" <public-webrtc@w3.org>
- Message-ID: <55F79F54.4050303@mozilla.com>
On 9/14/15 11:20 PM, Harald Alvestrand wrote: > On 09/14/2015 07:20 PM, Jan-Ivar Bruaroey wrote: >> On 9/14/15 9:17 PM, Harald Alvestrand wrote: >>> On 09/14/2015 02:38 PM, Martin Thomson wrote: >>>> What happens when MediaStreamTrack changes resolution to something >>>> outside of the negotiated envelope of the session? There is no >>>> language in the spec. Presumably if the resolution can be reduced, >>>> reduce it. Increasing resolution might be the only option we have in >>>> the case that the session has a resolution floor. >>> Section 5: >>> >>> Let's look at a slightly different situation starting from the same >>> point. In this case, instead of the first track attempting to apply >>> a conflicting constraint, the user physically locks the camera into >>> a mode where the fill light is on. At this point the source can no >>> longer satisfy the second track's mandatory constraint that the fill >>> light be off. The second track is transitioned into the muted state >>> and receives an|overconstrained| >>> <http://w3c.github.io/mediacapture-main/getusermedia.html#event-mediastreamtrack-overconstrained>event. >>> >>> More info in section 11.1.1. >> >> Constraints are properties of the application, not the browser, and >> no constraints were violated here. > > I don't even know what this means, but if it has meaning, I think > you're wrong. > the "light must be off" constraint is violated whenever the light is on. I'm not challenging the spec text, only its relevance to Martin's case. source -> track -> sink Camera fill-light switch = source property. PeerConnection negotiation window = sink property. While I find support for peerConnection being able to change a source *within constraints*, I find no support for sink properties trumping constraints. Instead I read: "Many sinks may .. take these [source setting] changes in stride. ... Others like the Recorder API may fail as a result of a source setting change." [1] I take this to mean the sink fails, not applyConstraints. [1] http://w3c.github.io/mediacapture-main/getusermedia.html#the-model-sources-sinks-constraints-and-settings .: Jan-Ivar :.
Received on Tuesday, 15 September 2015 04:32:50 UTC