Affecting pt= and rid= in WebRTC simulcast attributes are no longer supported

Published: | Categories: Audio & Video


Firefox 71 has stopped parsing the legacy pt= and rid= parameters in WebRTC simulcast attributes. The new format supported since Firefox 68 only requires a RID, so, for example,

a=simulcast: send rid=8 recv rid=9

has to be

a=simulcast: send 8 recv 9

Currently, video calls in Google Hangouts Meet and Whereby are broken due to this change.

Update: This change has been reverted in Firefox 71 to give services more time to adopt the new behaviour. Mozilla developers are planning to redo the change with Firefox 72.

Update 2: The change has been landed again to Firefox 72 after both Google and Whereby fixed their issue. If you run a similar service, please be sure to test it.