Provided by: pipewire-bin_1.0.5-1ubuntu3.1_amd64 
NAME
pipewire-client.conf - client.conf
DESCRIPTION
The PipeWire client configuration file.
SYNOPSIS
$XDG_CONFIG_HOME/pipewire/client.conf
/etc/pipewire/client.conf
/usr/share/pipewire/client.conf
/usr/share/pipewire/client.conf.d/
/etc/pipewire/client.conf.d/
$XDG_CONFIG_HOME/pipewire/client.conf.d/
$XDG_CONFIG_HOME/pipewire/client-rt.conf
/etc/pipewire/client-rt.conf
/usr/share/pipewire/client-rt.conf
/usr/share/pipewire/client-rt.conf.d/
/etc/pipewire/client-rt.conf.d/
$XDG_CONFIG_HOME/pipewire/client-rt.conf.d/
DESCRIPTION
Configuration for PipeWire native clients, and for PipeWire's ALSA plugin.
A PipeWire native client program selects the default config to load, and if nothing is specified, it
usually loads client.conf.
The ALSA plugin uses the client-rt.conf file, as do some PipeWire native clients such as pw-cat(1).
The configuration file format and lookup logic is the same as for pipewire.conf(5).
Drop-in configuration files client.conf.d/*.conf can be used, and are recommended. See pipewire.conf(5).
CONFIGURATION FILE SECTIONS
stream.properties
Configures options for native client streams.
stream.rules
Configures rules for native client streams.
alsa.properties
ALSA client configuration.
alsa.rules
ALSA client match rules.
In addition, the PipeWire context configuration sections may also be specified, see pipewire.conf(5).
STREAM PROPERTIES
The client configuration files contain a stream.properties section that configures the options for client
streams:
stream.properties = {
#node.latency = 1024/48000
#node.autoconnect = true
#resample.disable = false
#resample.quality = 4
#monitor.channel-volumes = false
#channelmix.disable = false
#channelmix.min-volume = 0.0
#channelmix.max-volume = 10.0
#channelmix.normalize = false
#channelmix.lock-volume = false
#channelmix.mix-lfe = true
#channelmix.upmix = true
#channelmix.upmix-method = psd # none, simple
#channelmix.lfe-cutoff = 150.0
#channelmix.fc-cutoff = 12000.0
#channelmix.rear-delay = 12.0
#channelmix.stereo-widen = 0.0
#channelmix.hilbert-taps = 0
#dither.noise = 0
#dither.method = none # rectangular, triangular, triangular-hf, wannamaker3, shaped5
#debug.wav-path = ""
}
Some of the properties refer to different aspects of the stream:
• General stream properties to identify the stream.
• General stream properties to classify the stream.
• How it is going to be scheduled by the graph.
• How it is going to be linked by the session manager.
• How the internal processing will be done.
• Properties to configure the media format.
Identifying Properties
These contain properties to identify the node or to display the node in a GUI application.
node.name
A (unique) name for the node. This is usually set on sink and sources to identify them as targets for
linking by the session manager.
node.description
A human readable description of the node or stream.
media.name
A user readable media name, usually the artist and title. These are usually shown in user facing
applications to inform the user about the current playing media.
media.title
A user readable stream title.
media.artist
A user readable stream artist
media.copyright
User readable stream copyright information
media.software
User readable stream generator software information
media.language
Stream language in POSIX format. Ex: en_GB
media.filename
File name for the stream
media.icon
Icon for the media, a base64 blob with PNG image data
media.icon-name
An XDG icon name for the media. Ex: audio-x-mp3
media.comment
Extra stream comment
media.date
Date of the media
media.format
User readable stream format information
object.linger = false
If the object should outlive its creator.
Classifying Properties
The classifying properties of a node are use for routing the signal to its destination and for
configuring the settings.
media.type
The media type contains a broad category of the media that is being processed by the node. Possible
values include 'Audio', 'Video', 'Midi'
media.category
What kind of processing is done with the media. Possible values include:
• Playback: media playback.
• Capture: media capture.
• Duplex: media capture and playback or media processing in general.
• Monitor: a media monitor application. Does not actively change media data but monitors activity.
• Manager: Will manage the media graph.
media.role
The Use case of the media. Possible values include:
• Movie: Movie playback with audio and video.
• Music: Music listening.
• Camera: Recording video from a camera.
• Screen: Recording or sharing the desktop screen.
• Communication: VOIP or other video chat application.
• Game: Game.
• Notification: System notification sounds.
• DSP: Audio or Video filters and effect processing.
• Production: Professional audio processing and production.
• Accessibility: Audio and Visual aid for accessibility.
• Test: Test program.
media.class
The media class is to classify the stream function. Possible values include:
• Video/Source: a producer of video, like a webcam.
• Video/Sink: a consumer of video, like a display window.
• Audio/Source: a source of audio samples like a microphone.
• Audio/Sink: a sink for audio samples, like an audio card.
• Audio/Duplex: a node that is both a sink and a source.
• Stream/Output/Audio: a playback stream.
• Stream/Input/Audio: a capture stream.
The session manager assigns special meaning to the nodes based on the media.class. Sink or Source
classes are used as targets for Stream classes, etc..
Scheduling Properties
node.latency = 1024/48000
Sets a suggested latency on the node as a fraction. This is just a suggestion, the graph will try to
configure this latency or less for the graph. It is however possible that the graph is forced to a
higher latency.
node.lock-quantum = false
When this node is active, the quantum of the graph is locked and not allowed to change automatically.
It can still be changed forcibly with metadata or when a node forces a quantum.
JACK clients use this property to avoid unexpected quantum changes.
node.force-quantum = INTEGER
While the node is active, force a quantum in the graph. The last node to be activated with this
property wins.
A value of 0 unforces the quantum.
node.rate = RATE
Suggest a rate (samplerate) for the graph. The suggested rate will only be applied when doing so
would not cause interruptions (devices are idle) and when the rate is in the list of allowed rates in
the server.
node.lock-rate = false
When the node is active, the rate of the graph will not change automatically. It is still possible to
force a rate change with metadata or with a node property.
node.force-rate = RATE
When the node is active, force a specific sample rate on the graph. The last node to activate with
this property wins.
A RATE of 0 means to force the rate in node.rate denominator.
node.always-process = false
When the node is active, it will always be joined with a driver node, even when nothing is linked to
the node. Setting this property to true also implies node.want-driver = true.
This is the default for JACK nodes, that always need their process callback called.
node.want-driver = true
The node wants to be linked to a driver so that it can start processing. This is the default for
streams and filters since 0.3.51. Nodes that are not linked to anything will still be set to the idle
state, unless node.always-process is set to true.
node.pause-on-idle = false
node.suspend-on-idle = false
When the node is not linked anymore, it becomes idle. Normally idle nodes keep processing and are
suspended by the session manager after some timeout. It is possible to immediately pause a node when
idle with this property.
When the session manager does not suspend nodes (or when there is no session manager), the
node.suspend-on-idle property can be used instead.
Session Manager Properties
node.autoconnect = true
Instructs the session manager to automatically connect this node to some other node, usually a sink
or source.
node.exclusive = false
If this node wants to be linked exclusively to the sink/source.
node.target = <node.name|object.id>
Where this node should be linked to. This can be a node.name or an object.id of a node. This property
is deprecated, the target.object property should be used instead, which uses the more unique
object.serial as a possible target.
target.object = <node.name|object.serial>
Where the node should link to ths can be a node.name or an object.serial.
node.dont-reconnect = false
When the node has a target configured and the target is destroyed, destroy the node as well. This
property also inhibits that the node is moved to another sink/source.
Note that if a stream should appear/disappear in sync with the target, a session manager
(WirePlumber) script should be written instead.
node.passive = false
This is a passive node and so it should not keep sinks/sources busy. This property makes the session
manager create passive links to the sink/sources. If the node is not otherwise linked (via a non-
passive link), the node and the sink it is linked to are idle (and eventually suspended).
This is used for filter nodes that sit in front of sinks/sources and need to suspend together with
the sink/source.
node.link-group = ID
Add the node to a certain link group. Nodes from the same link group are not automatically linked to
each other by the session manager. And example is a coupled stream where you don't want the output to
link to the input streams, making a useless loop.
stream.dont-remix = false
Instruct the session manager to not remix the channels of a stream. Normally the stream channel
configuration is changed to match the sink/source it is connected to. With this property set to true,
the stream will keep its original channel layout and the session manager will link matching channels
with the sink.
Audio Adapter Parameters
An audio stream (and also audio device nodes) contain an audio adapter that can perform, sample format,
sample rate and channel mixing operations.
Merger Parameters
The merger is used as the input for a sink device node or a capture stream. It takes the various channels
and merges them into a single stream for further processing.
The merger will also provide the monitor ports of the input channels and can apply a software volume on
the monitor signal.
monitor.channel-volumes = false
The volume of the input channels is applied to the volume of the monitor ports. Normally the monitor
ports expose the raw unmodified signal on the input ports.
Resampler Parameters
Source, sinks, capture and playback streams contain a high quality adaptive resampler. It uses sinc based
resampling with linear interpolation of filter banks to perform arbitrary resample factors. The resampler
is activated in the following cases:
• The hardware of a device node does not support the graph samplerate. Resampling will occur from the
graph samplerate to the hardware samplerate.
• The hardware clock of a device does not run at the same speed as the graph clock and adaptive
resampling is required to match the clocks.
• A stream does not have the same samplerate as the graph and needs to be resampled.
• An application wants to activate adaptive resampling in a stream to make it match some other clock.
PipeWire performs most of the sample conversions and resampling in the client (Or in the case of the
PulseAudio server, in the pipewire-pulse server that creates the streams). This ensures all the
conversions are offloaded to the clients and the server can deal with one single format for performance
reasons.
Below is an explanation of the options that can be tuned in the sample converter.
resample.quality = 4
The quality of the resampler. from 0 to 14, the default is 4.
Increasing the quality will result in better cutoff and less aliasing at the expense of (much) more
CPU consumption. The default quality of 4 has been selected as a good compromise between quality and
performance with no artifacts that are well below the audible range.
See Infinite Wave for a comparison of the performance.
resample.disable = false
Disable the resampler entirely. The node will only be able to negotiate with the graph when the
samplerates are compatible.
Channel Mixer Parameters
Source, sinks, capture and playback streams can apply channel mixing on the incoming signal.
Normally the channel mixer is not used for devices, the device channels are usually exposed as they are.
This policy is usually enforced by the session manager, so we refer to its documentation there.
Playback and capture streams are usually configured to the channel layout of the sink/source they connect
to and will thus perform channel mixing.
The channel mixer also implements a software volume. This volume adjustment is performed on the original
channel layout. ex: A stereo playback stream that is up-mixed to 5.1 has 2 a left an right volume
control.
channelmix.disable = false
Disables the channel mixer completely. The stream will only be able to link to compatible
sources/sinks with the exact same channel layout.
channelmix.min-volume = 0.0
channelmix.max-volume = 10.0
Gives the min and max volume values allowed. Any volume that is set will be clamped to these values.
channelmix.normalize = false
Makes sure that during such mixing & resampling original 0 dB level is preserved, so nothing sounds
wildly quieter/louder.
While this options prevents clipping, it can in some cases produce too low volume. Increase the
volume in that case or disable normalization.
channelmix.lock-volumes = false
Completely disable volume or mute changes. Defaults to false.
channelmix.mix-lfe = true
Mixes the low frequency effect channel into the front center or stereo pair. This might enhance the
dynamic range of the signal if there is no subwoofer and the speakers can reproduce the low frequency
signal.
channelmix.upmix = true
Enables up-mixing of the front center (FC) when the target has a FC channel. The sum of the stereo
channels is used and an optional lowpass filter can be used (see channelmix.fc-cutoff).
Also enabled up-mixing of LFE when channelmix.lfe-cutoff is set to something else than 0 and the
target has an LFE channel. The LFE channel is produced by adding the stereo channels.
If channelmix.upmix is true, the up-mixing of the rear channels is also enabled and controlled with
the channelmix-upmix-method property.
channelmix.upmix-method = psd
3 methods are provided to produce the rear channels in a surround sound:
1. none. No rear channels are produced.
2. simple. Front channels are copied to the rear. This is fast but can produce phasing effects.
3. psd. The rear channels as produced from the front left and right ambient sound (the difference
between the channels). A delay and optional phase shift are added to the rear signal to make the
sound bigger.
channelmix.lfe-cutoff = 150
Apply a lowpass filter to the low frequency effects. The value is expressed in Hz. Typical subwoofers
have a cutoff at around 150 and 200. The default value of 0 disables the feature.
channelmix.fc-cutoff = 12000
Apply a lowpass filter to the front center frequency. The value is expressed in Hz.
Since the front center contains the dialogs, a typical cutoff frequency is 12000 Hz.
This option is only active when the up-mix is enabled.
channelmix.rear-delay = 12.0
Apply a delay in milliseconds when up-mixing the rear channels. This improves spacialization of the
sound. A typical delay of 12 milliseconds is the default.
This is only active when the psd up-mix method is used.
channelmix.stereo-widen = 0.0
Subtracts some of the front center signal from the stereo channels. This moves the dialogs more to
the center speaker and leaves the ambient sound in the stereo channels.
This is only active when up-mix is enabled and a Front Center channel is mixed.
channelmix.hilbert-taps = 0
This option will apply a 90 degree phase shift to the rear channels to improve spacialization. Taps
needs to be between 15 and 255 with more accurate results (and more CPU consumption) for higher
values.
This is only active when the psd up-mix method is used.
dither.noise = 0
This option will add N bits of random data to the signal. This can be used to keep some amplifiers
alive during silent periods. This is usually used together with session.suspend-timeout-seconds to
disable suspend in the session manager.
dither.method = none
Optional dithering can be done on the quantized output signal.
There are 6 modes available:
1. none No dithering is done.
2. rectangular Dithering with a rectangular noise distribution.
3. triangular Dithering with a triangular noise distribution.
4. triangular-hf Dithering with a sloped triangular noise distribution.
5. wannamaker3 Additional noise shaping is performed on the sloped triangular dithering to move the
noise to the more inaudible range. This is using the 'F-Weighted' noise filter described by
Wannamaker.
6. shaped5 Additional noise shaping is performed on the triangular dithering to move the noise to
the more inaudible range. This is using the Lipshitz filter.
Dithering is only useful for conversion to a format with less than 24 bits and will be disabled
otherwise.
Debug Parameters
debug.wav-path = ''
Make the stream to also write the raw samples to a WAV file for debugging puposes.
Format Properties
Streams and also most device nodes can be configured in a certain format with properties.
audio.rate = RATE
Forces a samplerate on the node.
audio.channels = INTEGER
The number of audio channels to use. Must be a value between 1 and 64.
audio.format = FORMAT
Forces an audio format on the node. This is the format used internally in the node because the graph
processing format is always float 32.
Valid formats include: S16, S32, F32, F64, S16LE, S16BE, ...
audio.allowed-rates
An array of allowed samplerates for the node. ex. '[ 44100 48000 ]'
STREAM RULES
You can add match rules, see pipewire(1) to set properties for certain streams and filters.
stream.rules and filter.rules provides an update-props action that takes an object with properties that
are updated on the node object of the stream and filter.
Add a stream.rules or filter.rules section in the config file like this:
stream.rules = [
{
matches = [
{
# all keys must match the value. ! negates. ~ starts regex.
application.process.binary = "firefox"
}
]
actions = {
update-props = {
node.name = "My Name"
}
}
}
]
Will set the node.name of Firefox to 'My Name'.
ALSA PROPERTIES
An alsa.properties section can be added to configure ALSA specific client config.
alsa.properties = {
#alsa.deny = false
#alsa.format = 0
#alsa.rate = 0
#alsa.channels = 0
#alsa.period-bytes = 0
#alsa.buffer-bytes = 0
#alsa.volume-method = cubic # linear, cubic
}
alsa.deny
Denies ALSA access for the client. Useful in rules or PIPEWIRE_ALSA environment variable.
alsa.format
The ALSA format to use for the client. This is an ALSA format name. default 0, which is to allow all
formats.
alsa.rate
The samplerate to use for the client. The default is 0, which is to allow all rates.
alsa.channels
The number of channels for the client. The default is 0, which is to allow any number of channels.
alsa.period-bytes
The number of bytes per period. The default is 0 which is to allow any number of period bytes.
alsa.buffer-bytes
The number of bytes in the alsa buffer. The default is 0, which is to allow any number of bytes.
alsa.volume-method = cubic | linear
This controls the volume curve used on the ALSA mixer. Possible values are cubic and linear. The
default is to use cubic.
ALSA RULES
It is possible to set ALSA client specific properties by using Match rules, see pipewire(1). You can set
any of the above ALSA properties or any of the stream.properties.
Example
alsa.rules = [
{ matches = [ { application.process.binary = "resolve" } ]
actions = {
update-props = {
alsa.buffer-bytes = 131072
}
}
}
]
ENVIRONMENT VARIABLES
See pipewire(1) for common environment variables. Many of these also apply to client applications.
The environment variables also influence ALSA applications that are using PipeWire's ALSA plugin.
PIPEWIRE_ALSA
This can be an object with properties from alsa.properties or stream.properties that will be used to
construct the client and streams.
For example:
PIPEWIRE_ALSA='{ alsa.buffer-bytes=16384 node.name=foo }' aplay ...
Starts aplay with custom properties.
PIPEWIRE_NODE
Instructs the ALSA client to link to a particular sink or source object.serial or node.name.
For example:
PIPEWIRE_NODE=alsa_output.pci-0000_00_1b.0.analog-stereo aplay ...
Makes aplay play on the give audio sink.
AUTHORS
The PipeWire Developers <https://gitlab.freedesktop.org/pipewire/pipewire/issues>; PipeWire is available
from <https://pipewire.org>
SEE ALSO
libpipewire-module-protocol-pulse(7), pipewire.conf(5), pipewire-pulse(1), pipewire-pulse-modules(7)
PipeWire 1.0.5 pipewire-client.conf(5)