Comment 6 for bug 1974089

Given that the previous build for Focal (3.0.17.4-0ubuntu1~20.04.sav0 on 28/4/2022) worked fine the focus here for this bug needs to be on precisely what changed between that build and the current build (3.0.17.4-2~20.04.sav0 on 17/5/2022). All other considerations about local builds are not really relevant, as the libraries used for such builds can easily be quite different than those used for the builds uploaded here to Launchpad.

Looking into this further over the past day one change stood out to me, which was the addition of a "Recommends" vlc-plugin-pipewire to the main vlc package, as per the Debian 3.0.17.4-2 VLC package. It turns out that this vlc-plugin-pipewire package is the cause of the no audio bug.

With my test VirtualBox 18.04 Bionic system and my own 16.04 Xenial based systems the "Recommends" packages are not installed automatically. On the VBox 18.04 installation packages under Recommends are not installed due the existence of the file /etc/apt/apt.conf with the following contents:

APT::Install-Recommends "0" ;
APT::Install-Suggests "0" ;

This file /etc/apt/apt.conf with the above settings is not present on the VBox 20.04 install and so it appears that all "Recommends" packages are therefore installed by default on Ubuntu 20.04 (and presumably newer, ie. 22.04 Jammy) systems, which is the same default as for all Debian systems.

Based on the above, in the test VBox 20.04 system where I installed VLC and did replicate the bug, today I removed vlc-plugin-pipewire entirely and as soon as that package was gone the audio device was available as usual in VLC and sound worked fine once again. So the resolution to this bug for Focal users at the present moment is as follows:

  sudo apt-get purge vlc-plugin-pipewire

From the README file of src:vlc-plugin-pipewire is this revealing comment:

"The plug-in runs automatically assuming that PipeWire is available in the user session. No further actions are required."

So it seems that as soon as vlc-plugin-pipewire is installed it "takes over" the VLC audio output which is then directed to PipeWire. However, given that no Debian/Ubuntu systems are using PipeWire as the audio provider (user session level) by default as yet, then there is no sound output.

A revision of the latest VLC builds (for all series) will be forthcoming, which will "demote" the vlc-plugin-pipewire package from Recommends to Suggests, which should stop that package from being automatically installed on Ubuntu 20.04 Focal (and newer) systems. Then those who are pioneering the way with PipeWire use can choose to install the vlc-plugin-pipewire package if they want, and choose to deal with any/all complications that arise from doing so.