contrib/pipewire/README.md

contrib/pipewire how to

Intro

pipewire is a modern multimedia server. Quoting gentoo wiki, it's strenghts are:

• Minimal latency capture/playback of audio and video
• Real-time multimedia processing
• Multi-process architecture allowing multimedia content sharing between applications
• Seamless support for ALSA, Bluez, GStreamer, JACK, PulseAudio..
• applications sandboxing support with Flatpak

Getting pipewire to run is relatively easy on CRUX. This is a simple guide and relies on further reading upon official and unofficial resources.

⚠️ Work in progress!

Although pipewire works perfectly fine with everything I have thrown at it by date (HDMI, USB, Bluetooth, ..) this article is incomplete. You can make it better by expanding it.

Prerequisites

• working kernel with alsa audio
• opt/alsa-utils will be installed by default as a dependency and needs to be configured by the user
• pipewire requires a session-manager to run to operate correctly. The only supported implementation available right now is contrib/wireplumber and is installed by default
• currently, pipewires default config likes to make use of opt/alsa-ucm-conf, consider installing that alongside the default dependency opt/alsa-utils

Optional prerequisites

• pipewire needs pulseaudio to be built with xorg-libxtst around to have the pulseaudio portal available
  • prt-get depinst xorg-libxtst && prt-get update -fr pulseaudio
• contrib/rtkit and a realtime compatible kernel to help with latency, add your user to rtkit group to be able to make use of it
  • an stackoverflow question on the topic
  • Real-Time Linux collaborative project
  • Arch wiki
  • linuxaudio.org wiki
• please look at contrib/pipewire/Pkgfile for further optional dependencies listed and rebuild the package after installing new optional dependencies

Running pipewire

Setting up pipewire

💡 Note

Mostly nothing of that chapter is normally needed to get a working pipewire session that manages your audio and video. Doing so allows for a better control of your settings, as well as running compatibility layers provided by pipewire for e.g. pulseaudio.

pipewire will always leverage alsa, so you should configure that first. Do that with e.g. alsamixer and use alsactl store to store those settings. Afterwards, we can configure /etc/rc.conf to add alsa and dbus to the SERVICES to be started.

⚠️ Things to keep in mind

Currently, pipewires default config format might always change, so its advised to check either upstream or in /usr/share/pipewire for changes.

The default config can be copied from /usr/share/pipewire to /etc/pipewire to be modified. Alternatively, it will read the config from $XDG_CONFIG_HOME/pipewire.

With the config moved to either place, you should enable wireplumber. In pipewire.conf, almost at the bottom of the file, you will find the context.exec section where you should uncomment the lines for wireplumber:

#{ path = "/usr/bin/pipewire-media-session" args = ""
#  condition = [ { exec.session-manager = null } { exec.session-manager = true } ] }

💡 Quality of life To make things easier to work with, you might opt for smaller configuration files, e.g. something like the following structure:

/etc/pipewire
├── pipewire-pulse.conf.d
│   ├── 10-rtmodule.conf
│   ├── 92-lowlatency.conf
│   └── 10-tcp.conf
└── pipewire.conf.d
    ├── 10-sessions.conf
    ├── 10-rtmodule.conf
    ├── 92-lowlatency.conf
    ├── 10-settings.conf
    └── 10-rates.conf

The same words count for wireplumber which stores its default configs in /usr/share/wireplumber. You can copy to /etc/wireplumber and so on.

Managing a user session

You are now ready to try out to run a pipewire session. From a users shell run /usr/bin/pipewire - if there aren't any serious errors your session should be working.

You can verify your running pipewire session by examining the output of pw-dump.

Running pipewire-pulse as a pulseaudio-server replacement

It is crucial that you make sure that pulseaudio is not started automagically before you start your pipewire server, or it will not work. You can do that by adding autospawn = no to /etc/pulse/client.conf.

After that, you can theoretically start pulseaudio-pulse in another terminal and run pactl info to see what Server Name it returns. It should say Server Name: PulseAudio (on PipeWire 0.3.yy). Success!

You can have that start by default by editing your sessions configurations, e.g.:

$ cat /etc/pipewire/pipewire.conf.d/10-sessions.conf
context.exec = [
    { path = "/usr/bin/wireplumber" args = ""
      condition = [ { exec.session-manager = null } { exec.session-manager = true } ] }
    { path = "/usr/bin/pipewire" args = "-c pipewire-pulse.conf"
      condition = [ { exec.pipewire-pulse = null } { exec.pipewire-pulse = true } ] }
]

Now you can use tools like contrib/pavucontrol or contrib/ncpamixer to control your typical sources and sink settings. Ports like opt/firefox-bin and whatever else uses pulseaudio should work ootb for you too.

Running jack applications through pipewire

⚠️ Work in progress!

There is no jack port in CRUX and therefor this port lacks support of it.

Debbuging pipewire

You can run pipewire like that from a terminal: PIPEWIRE_DEBUG=3 pipewire Make sure to kill your previous session.

tl;dr

„I don't have any time to read up on stuff myself, tell me what I need to do right now to get this hot mess!“ -some user

• optional: prt-get depinst xorg-libxtst pulseaudio et al, see Pkgfile
• install prt-get depinst pipewire
• setup pipewire to use wireplumber as your session-manager
• execute while starting your X11/Wayland-Session: /usr/bin/pipewire & /usr/bin/pipewire-pulse & /usr/bin/wireplumber (setting up a basic config is cooler though)

Ressources

• Official pipewire wiki
• Official ALSA wiki
• Gentoo wiki - ALSA
• Gentoo wiki - Pipewire
• Arch wiki - ALSA
• Arch wiki - Pipewire

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