W3C home > Mailing lists > Public > public-webrtc@w3.org > March 2019

[mediacapture-main] Proposal: Remove onoverconstrained

From: Henrik Boström <hbos@google.com>
Date: Mon, 18 Mar 2019 13:55:51 +0100
Message-ID: <CAEbRw2w5tEbkeQLuOipRps8euVHayND0PTnwNEny2-D1MbtVmQ@mail.gmail.com>
To: public-webrtc@w3.org
getUserMedia() gives you a track with the capabilities/settings you asked
for. Even with the right settings, you might not get what you asked for.
Example: poor lighting condition => less FPS than the camera aims for. This
triggers “onoverconstrained”.



   Overconstrained mutes the track… (foot-gun!)

      …making it unusable (silent/black).

      …which contradicts the definition of “mute”, which is:
      The muted/unmuted state of a track reflects whether the source
      provides any media at this moment.

      (Separate discussion: If applicable to remote WebRTC tracks, “onmute”
      has a different meaning: negotiation triggered it not being used to

   Quoting Jan-Ivar

      It's redundant: just measure the output directly and react to it.

      It's undesired: demand has not materialized in 5 years.


Remove "onoverconstrained" from the spec.

No browser has implemented it and there seem to already be consensus
<https://github.com/w3c/mediacapture-main/issues/573> about removing it
among browser implementors and editors. If you don't agree, speak up.

(Slides 38-39 of WebRTC March Virtual Interim
this topic, but we never had the time to discuss it then.)
Received on Monday, 18 March 2019 12:56:25 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 19:18:47 UTC