____  _          __        ___
|  _ \(_)_ __   __\ \      / (_)_ __ ___
| |_) | | '_ \ / _ \ \ /\ / /| | '__/ _ \
|  __/| | |_) |  __/\ V  V / | | | |  __/
|_|   |_| .__/ \___| \_/\_/  |_|_|  \___|
        |_|
           - on Ubuntu Linux -
          pastebin.com/7kx7PV9s


o==========o
| Contents |
o==========o

 A. General
    1. Install tips
    2. What is PW and how to use it

B. Behringer 404 HD

C. Utilities, mixers etc.

D. Stop PW

X. References

     -<>-<>-<>-<>-<>-



o============o
| A. General |
o============o

1. Install tips
~~~~~~~~~~~~~~~
PW should be installed and properly configured out of the box. But make sure you've installed:

    pipewire-jack
    pipewire-alsa
    wireplumber
    qpwgraph
    ubuntustudio-pipewire-config (!) (integrate PW w/ Jack native apps)

Must one also install 'jackd2' (w/ realtime priorities)?

Test if PW is active:

    systemctl --user status pipewire

And note that you still need to use PW's Alsa-Midi to Jack-Midi bridge (see Qpwgraph) for Reaper! Reaper still only works with Jack-Midi and NOTHING else.

It looks like PW and Jack (and Alsa utilities like "alsamixer") don't work with HDMI audio, but with PW they do.

2. What is PW and how to use it
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PW is a replacement for the audio servers PulseAudio and Jack. Audio servers are needed to let the audio driver, Alsa, "serve" more than one single appication at the same time. With PW it's like both of 'm are installed and working next to each other like nothing has changed for applications that need either of them. However, apps are meant to "move" from PA or Jack to PW and to support it natively as their audio server.

Notice that you still need to use an Alsa-Midi to Jack-Midi bridge for Reaper! See above.



o=====================o
| B. Behringer 404 HD |
o=====================o

See [3a] and [3b]



o===========================o
| C. Utilities, mixers etc. |
o===========================o

Use qpwgraph. There's also Helvum (in the std. repo's) and Cable [4] and PipeMixer [2, won't compile on 'Buntu 24.04]. Qjackctl still works just fine with PW.

Colors and icons in Qpwgraph:
- icons: pw, alsa and jack
- red: Midi bridge/Jack Midi
- green: audio in/out
- purple: alsa Midi



o============o
| D. Stop PW |
o============o

Stop Pipewire like so:

    systemctl --user stop pipewire.service
    systemctl --user stop pipewire.socket
    systemctl --user stop wireplumber.service

But you don't have to: PA and Jack applications work well with PW. However, after the command above you can't simply run apps like jackd etc. anymore like in the times before PW.



o===============o
| X. References |
o===============o

[1] Arch Linux wiki:
    https://wiki.archlinux.org/title/PipeWire

[2] Pipemixer (CLI)
    https://github.com/heather7283/pipemixer

[3] [a] PW and the Behringer 404 HD on LM forum:
        https://linuxmusicians.com/viewtopic.php?p=169684 
     
    [b] Link referred to there:
     https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Virtual-Devices#virtual-sinks

[4] Cable
    https://github.com/magillos/Cable