PipeWire: Difference between revisions
(update realtime configuration) |
m (fixup heading level) |
||
| Line 66: | Line 66: | ||
</pre> | </pre> | ||
== Realtime scheduling == | === Realtime scheduling === | ||
For realtime scheduling, it is recommended to use rtkit, | For realtime scheduling, it is recommended to use rtkit, | ||
Revision as of 09:12, 30 May 2022
 The instructions below have not been thoroughly tested and may break things. |
PipeWire is a multimedia processing engine that aims to improve audio and video handling on Linux.
Prerequisites
Audio Group
When elogind is not available, the user has to be added to the audio group. The user must log in for this to take effect.
# addgroup <user> audio
D-Bus
PipeWire requires a running D-Bus session. If you use a full desktop environment this will probably be started automatically, but with minimal window managers it must be done manually.
# apk add dbus dbus-openrc dbus-x11 # rc-service dbus start # rc-update add dbus default
Then use dbus-launch whenever you start an X or Wayland session. For example:
$ dbus-launch --exit-with-session sway
XDG_RUNTIME_DIR
If you are not using a Desktop Manager, ensure that your XDG_RUNTIME_DIR is set to a user-writable location. By default for pulseaudio this is /run/user/1000/ or /tmp. If this is not set, pipewire will create a directory in your home folder instead, called ~/pulse, and on attempting to run Pavucontrol or pactl, you will get the following error:
$ pactl list Connection failure: Connection refused pa_context_connect() failed: Connection refused
Installation and configuration
# apk add pipewire wireplumber
Create a custom configuration file in /etc/pipewire/pipewire.conf:
# mkdir /etc/pipewire # cp /usr/share/pipewire/pipewire.conf /etc/pipewire/
Add the following line to the context.exec section at the bottom of /etc/pipewire/pipewire.conf:
{ path = "wireplumber" args = "" }
Enable the snd_seq kernel module for ALSA support.
# modprobe snd_seq # echo snd_seq >> /etc/modules
Realtime scheduling
For realtime scheduling, it is recommended to use rtkit,
# apk add rtkit
and then add your user to the `rtkit` group.
Alternatively, ensure your user has the right ulimit permissions. You generally need (limits.conf format):
@audio - memlock 256 @audio - nice -11 @audio - rtprio 88
This allows a member of the audio group to have the right permissions for PipeWire to use realtime scheduling without rtkit.
ALSA
# apk add pipewire-alsa
ALSA support works out of the box if you have the pipewire-alsa package
PulseAudio
PipeWire can run a PulseAudio daemon which should allow all existing PulseAudio applications to be used with the PipeWire backend.
# apk add pipewire-pulse
Uncomment the following line in /etc/pipewire/pipewire.conf:
{ path = "/usr/bin/pipewire" args = "-c pipewire-pulse.conf" }
It should be automatically enabled.
JACK
If you will be using PipeWire for JACK applications install the required package and make system wide links to the PipeWire replacement JACK libraries (I have not had success using pw-jack). You will not need to start a JACK server.
# apk add pipewire-jack # ln -sf /usr/lib/pipewire-0.3/jack/libjackserver.so.0 /usr/lib/libjackserver.so.0 # ln -sf /usr/lib/pipewire-0.3/jack/libjacknet.so.0 /usr/lib/libjacknet.so.0 # ln -sf /usr/lib/pipewire-0.3/jack/libjack.so.0 /usr/lib/libjack.so.0
Video
Video should work out-of-the-box with v4l2 devices (e.g. a lot of webcams) and GStreamer applications.
Bluetooth headset
Requires pipewire-spa-bluez package in addition to pipewire-pulse daemon to be installed.
Automatic bluetooth profile selection
To automatically switch between HSP/HFP and A2DP profiles when an input stream is detected, set the bluez5.autoswitch-profile property to true:
/etc/pipewire/media-session.d/bluez-monitor.conf
...
rules = [
{
...
actions = {
update-props = {
...
bluez5.autoswitch-profile = true
...
Screen sharing on Wayland
You will need the right xdg-desktop-portal backend for your desktop environment. Screen sharing is known to work on:
- GNOME with
xdg-desktop-portal-gtk - KDE Plasma with
xdg-desktop-portal-kdeand Firefox - Sway with
xdg-desktop-portal-wlrand Firefox
Usage
Start the PipeWire media server. You'll probably get quite a few errors but just ignore them for now.
$ pipewire
In a different terminal window check the default output device. I don't yet know how this default can be changed for all applications, so you'd better hope it's right!
# apk add pipewire-tools $ pw-cat -p --list-targets
Test sound is working using an audio file in a format supported by libsndfile (e.g. flac, opus, ogg, wav).
$ pw-cat -p test.flac
If you have a microphone test audio recording is working.
$ pw-cat -r --list-targets $ pw-cat -r recording.flac (Speak for a while then stop it with Ctrl+c) $ pw-cat -p recording.flac
Test PulseAudio clients using a media player (most use PulseAudio) and if you use JACK test that too:
# apk add jack-example-clients $ jack_simple_client
You should hear a sustained beep.
If you are happy everything is working, make PipeWire start automatically when your X or Wayland session starts. For example, you could add the pipewire command to ~/.xinitrc or your window manager's config file.
Troubleshooting
`pw-cat -p --list-targets` shows no targets
First, check whether ALSA knows about your sound card:
aplay -l
If sound devices are found, the issue is with your pipewire configuration. Consider double-checking the instructions above.
Otherwise, your sound card may not be supported in the version of the Linux Kernel you're running. You should search online for fixes relating to your current kernel version and the codec of your sound card. You can find each of these with:
uname -r cat /proc/asound/card0/codec* | grep Codec
Quick Configuration
You might want to use pavucontrol to have a simple GUI app for controlling sound, outputs, etc, in which case:
# apk add pavucontrol