Home / ubuntu / Questions / 923990
In Process
user877329
Asked: 2017-06-11 00:15:52 +0800 CST

JACK, PulseAudio and Firefox: Enable JACK for firefox in the near future

  • 772

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.

firefox

2 Answers

  1. I use the following script I call "pulsejack". Call it without arguments and it connects an existing jackd to PulseAudio. Called with any arguments, it starts up jackd with those arguments and then connects it to PulseAudio. Firefox can pick up from PulseAudio then.

    #/bin/sh
if [ $# -gt 1 ]
then
    killall jackd 2> /dev/null && sleep 2
    jackd "$@" && sleep 2
fi
pactl load-module module-jack-sink channels=2
pactl load-module module-jack-source channels=2
pacmd set-default-sink jack_out
pacmd set-default-source jack_in

    You may need to run sudo apt install pulseaudio-module-jack in order to get the respective modules.

    • 2

  2. 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.

    • 0