Firefox bug #1345661 was closed with "WONTFIX", which certainly will break my current setup in the near future (I play firefox sound through alsa_in:loopback->JACK). I have read that Firefox has JACK support now, though it is not yet stable. Questions:

  1. Will JACK support in Firefox be officially supported?
  2. Will Ubuntu enable JACK support in Firefox before raw ALSA support ends?

I the answer is No No, how can I reliable restore functionality without breaking JACK? It is possible to run PA through alsa_in, but I guess that would introduce some extra latency, break AV sync, or introduce signal distortion due to multiple resamplers.


I've compiled mozilla-central firefox with jack support and output (sources) Automatically get created when you visit a site with audio (i.e youtube).

However - input sink sources do not get created ; I don't see them appear in cadence/jack patch bay. So anything that relies on Mic input fails. i.e meet.jit.si / webrtc tests...

Another problem is that even using the pulseaudio bridge ; the same issue input sources even when connected correctly to the pulse-sink don't get recognized by firefox. In Chrome however Mic input correctly uses the plugged capture to pulse-sink. So I think this is a firefox bug in the way it detects and reports Mic presence information.

My personal view is that the Input/capture sink sources should be created on firefox start up rather than on a per-tab/site basis as with the output sources in the jack only case.

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  • Mic presence detection? In the old days, there was no such thing. It was always "present" as an input jack on the soundcard, and it still is, on more professional stuff. Mine has 2 XLR connectors that can be used as either line or mic depending on gain. For JACK, it should just create input ports. – user877329 Jun 15 '17 at 6:02
  • in firefox/adobe flash. hardware devices (alsa) only are detected. in chrome/pepperflash software devices (pulse and loopback) are also detected. I'm not sure what causes the difference. – ravery Jul 13 '17 at 11:26

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