User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:82.0) Gecko/20100101 Firefox/82.0

Steps to reproduce:

I tested it on Ubuntu 18.04.
Visit https://p2p.chat/
Create a new room, allow microphone.

Actual results:

Video recording is not asked and does not work with js error:

MediaStreamError
constraint: "frameRate"
message: "Constraints could be not satisfied."
name: "OverconstrainedError"
stack: ""

Expected results:

Start recording video. It works with chromium.

It might come from around here : https://searchfox.org/mozilla-central/rev/c938c7416c633639a5c8ce4412be586eefb48005/dom/media/MediaManager.cpp#2935

Hi carnould,

I followed your instructions but I was unable to reproduce the issue. I checked on Firefox's developer console and browser console, but there is no js error. We tried this on two different machines with Ubuntu 20.04 on the latest Nightly and Release versions and we always got the prompt to allow Camera/Mic.

Could you please specify where we should search for that particular error?

Thanks in advance,
Virginia

Jib, are we not doing framerate reduction in software?

I don't believe so for cameras, not to constraints anyway. That's bug 1286945. We do it for screen capture, and we may also be doing it for privacy to resolve concurrent capture (at least we do for width and height, unsure about frameRate there).

Workaround

https://p2p.chat/ could work around this by using ideal instead of required constraints. E.g. {frameRate: 10} instead of {frameRate: {max: 10}}. Until about 4 days ago, this was on them, but the spec changed, so now it's on us, as it should be. The original API was too much on people.