I was trying to watch videos through the Librewolf web browser on a FreeBSD machine, however there was no audio, this was strange since I could get audio to work using yt-dlp + mpv to watch internet videos through sites like YouTube and Invidious. This issue also happened on Firefox.
We want to tell Firefox to use a certain backend for audio that FreeBSD supports. Personally I have only tried using oss and sndio as backends, of the two I personally use sndio. If you want to use oss or sndio it must be installed from either ports or pkg
pkg install oss
or
pkg install sndio
go to `about:config` in the Firefox search bar, then type
"media.cubeb.backend" and set it to string with the string being the backend
you want to use i.e "oss" or "sndio", if you set it to sndio you must
start the sndio daemon (sndiod), oss seems to just work as long as
it's installed.
sndiod can be configure to run at boot time by adding
sndiod_enable="YES"
to your `/etc/rc.conf`