why does the terminal start pulseaudio?

[Piscium]

On Mon, 6 Jul 2020 at 06:43, Ralf Mardorf <ralf.mardorf at alice-dsl.net> wrote:

> Firefox for Arch Linux is build with alsa and jack support.
>
> [rocketmouse at archlinux tmp]$ asp checkout firefox
> Cloning into 'firefox'...
> done.
> [rocketmouse at archlinux tmp]$ grep -ee.alsa -ee.jack firefox/repos/extra-x86_64/PKGBUILD
> ac_add_options --enable-alsa
> ac_add_options --enable-jack
>
> Unfortunately jack support is odd. Firefox doesn't show up as a jack
> client when running, just if you start e.g. a YouTube video Firefox
> auto-connects with playback_1 and playback_2.

The programs I use to listen to music (vlc, audacious, mixxx, etc) all
have a way to configure the output and I can choose between Jack,
Pulse, and for some also Alsa.

But how exactly do you configure Firefox to use Jack and not
Pulseaudio? I could not see anything in the FF settings dialogue box.
Is there any setting in about:config? And what about Chromium?