Provided by: pipewire-bin_1.2.4-1ubuntu1_amd64 
NAME
pipewire.conf - pipewire.conf
DESCRIPTION
The PipeWire server configuration file
SYNOPSIS
$XDG_CONFIG_HOME/pipewire/pipewire.conf
/etc/pipewire/pipewire.conf
/usr/share/pipewire/pipewire.conf
/usr/share/pipewire/pipewire.conf.d/
/etc/pipewire/pipewire.conf.d/
$XDG_CONFIG_HOME/pipewire/pipewire.conf.d/
DESCRIPTION
PipeWire is a service that facilitates sharing of multimedia content between devices and applications.
On startup, the daemon reads a main configuration file to configure itself. It executes a series of
commands listed in the config file.
The config file is looked up in the order listed in the SYNOPSIS. The environment variables
PIPEWIRE_CONFIG_DIR, PIPEWIRE_CONFIG_PREFIX and PIPEWIRE_CONFIG_NAME can be used to specify an
alternative config directory, subdirectory and file respectively.
Other PipeWire configuration files generally follow the same lookup logic, replacing pipewire.conf with
the name of the particular config file.
DROP-IN CONFIGURATION FILES
All *.conf files in the pipewire.conf.d/ directories are loaded and merged into the configuration.
Dictionary sections are merged, overriding properties if they already existed, and array sections are
appended to. The drop-in files have same format as the main configuration file, but only contain the
settings to be modified.
As the pipewire.conf configuration file contains various parts that must be present for correct
functioning, using drop-in files for configuration is recommended.
Example
A configuration file ~/.config/pipewire/pipewire.conf.d/custom.conf to change the value of the
default.clock.min-quantum setting in pipewire.conf:
context.properties = {
default.clock.min-quantum = 128
}
CONFIGURATION FILE FORMAT
The configuration file is in 'SPA' JSON format.
The configuration file contains top-level keys, which are the sections. The value of a section is either
a dictionary, { }, or an array, [ ]. Section and dictionary item declarations have KEY = VALUE form, and
are separated by whitespace. For example:
context.properties = { # top-level dictionary section
key1 = value # a simple value
key2 = { key1 = value1 key2 = value2 } # a dictionary with two entries
key3 = [ value1 value2 ] # an array with two entries
key4 = [ { k = v1 } { k = v2 } ] # an array of dictionaries
}
context.modules = [ # top-level array section
value1
value2
]
The configuration files can also be written in standard JSON syntax, but for easier manual editing, the
relaxed 'SPA' variant is allowed. In 'SPA' JSON:
• : to delimit keys and values can be substituted by = or a space.
• " around keys and string can be omitted as long as no special characters are used in the strings.
• , to separate objects can be replaced with a whitespace character.
• # can be used to start a comment until the line end
CONFIGURATION FILE SECTIONS
context.properties
Dictionary. These properties configure the PipeWire instance.
context.spa-libs
Dictionary. Maps plugin features with globs to a spa library.
context.modules
Array of dictionaries. Each entry in the array is a dictionary with the name of the module to load,
including optional args and flags. Most modules support being loaded multiple times.
context.objects
Array of dictionaries. Each entry in the array is a dictionary containing the factory to create an
object from and optional extra arguments specific to that factory.
context.exec
Array of dictionaries. Each entry in the array is dictionary containing the path of a program to
execute on startup and optional args.
This array used to contain an entry to start the session manager but this mode of operation has since
been demoted to development aid. Avoid starting a session manager in this way in production
environment.
node.rules
Array of dictionaries. Match rules for modifying node properties on the server.
device.rules
Array of dictionaries. Match rules for modifying device properties on the server.
CONTEXT PROPERTIES
Available PipeWire properties in context.properties and possible default values.
clock.power-of-two-quantum = true
The quantum requests from the clients and the final graph quantum are rounded down to a power of two.
A power of two quantum can be more efficient for many processing tasks.
context.data-loop.library.name.system
The name of the shared library to use for the system functions for the data processing thread. This
can typically be changed if the data thread is running on a realtime kernel such as EVL.
loop.rt-prio = -1
The priority of the data loops. The data loops are used to schedule the nodes in the graph. A value
of -1 uses the default realtime priority from the module-rt. A value of 0 disables realtime
scheduling for the data loops.
loop.class = [ data.rt .. ]
An array of classes of the data loops. Normally nodes are assigned to a loop by name or by class.
Nodes are by default assigned to the data.rt class so it is good to have a data loop of this class as
well.
context.num-data-loops = 1
The number of data loops to create. By default 1 data-loop is created and all nodes are scheduled in
this thread. A value of 0 disables the real-time data loops and schedules all nodes in the main
thread. A value of -1 spawns as many data threads as there are cpu cores.
context.data-loops = [ ... ]
This controls the data loops that will be created for the context. Is is an array of data loop
specifications, one entry for each data loop to start:
context.data-loops = [
{
#library.name.system = support/libspa-support
loop.rt-prio = -1
loop.class = [ data.rt .. ]
thread.name = data-loop.0
thread.affinity = [ 0 1 ]
}
...
]
A specific priority, classes and name can be given with loop.rt-prio, loop.class and thread.name
respectively. It is also possible to pin the data loop to specific CPU cores with the thread.affinity
property.
core.daemon = false
Makes the PipeWire process, started with this config, a daemon process. This means that it will
manage and schedule a graph for clients. You would also want to configure a core.name to give it a
well known name.
core.name = pipewire-0
The name of the PipeWire context. This will also be the name of the PipeWire socket clients can
connect to.
cpu.zero.denormals = false
Configures the CPU to zero denormals automatically. This will be enabled for the data processing
thread only, when enabled.
cpu.vm.name = null
This will be set automatically when the context is created and will contain the name of the VM. It is
typically used to write match rules to set extra properties.
default.clock.rate = 48000
The default clock rate determines the real time duration of the min/max/default quantums. You might
want to change the quantums when you change the default clock rate to maintain the same duration for
the quantums.
default.clock.allowed-rates = [ ]
It is possible to specify up to 32 alternative sample rates. The graph sample rate will be switched
when devices are idle. Note that this is not enabled by default for now because of various kernel and
Bluetooth issues. Note that the min/max/default quantum values are scaled when the samplerate
changes.
default.clock.min-quantum = 32
Default minimum quantum.
default.clock.max-quantum = 8192
Default maximum quantum.
default.clock.quantum = 1024
Default quantum used when no client specifies one.
default.clock.quantum-limit = 8192
Maximum quantum to reserve space for. This is the maximum buffer size used in the graph, regardless
of the samplerate.
default.clock.quantum-floor = 4
Minimum quantum to reserve space for. This is the minimum buffer size used in the graph, regardless
of the samplerate.
default.video.width
Default video width
default.video.height
Default video height
default.video.rate.num
Default video rate numerator
default.video.rate.denom
Default video rate denominator
library.name.system = support/libspa-support
The name of the shared library to use for the system functions for the main thread.
link.max-buffers = 64
The maximum number of buffers to negotiate between nodes. Note that version < 3 clients can only
support 16 buffers. More buffers is almost always worse than less, latency and memory wise.
log.level = 2
The default log level used by the process.
mem.allow-mlock = true
Try to mlock the memory for the realtime processes. Locked memory will not be swapped out by the
kernel and avoid hickups in the processing threads.
mem.warn-mlock = false
Warn about failures to lock memory.
mem.mlock-all = false
Try to mlock all current and future memory by the process.
settings.check-quantum = false
Check if the quantum in the settings metadata update is compatible with the configured limits.
settings.check-rate = false
Check if the rate in the settings metadata update is compatible with the configured limits.
support.dbus = true
Enable DBus support. This will enable DBus support in the various modules that require it. Disable
this if you want to globally disable DBus support in the process.
vm.overrides = { default.clock.min-quantum = 1024 }
Any property in the vm.overrides property object will override the property in the context.properties
when PipeWire detects it is running in a VM. This is deprecated, use the context.properties.rules
instead.
context.modules.allow-empty = false
By default, a warning is logged when there are no context.modules loaded because this likely
indicates there is a problem. Some applications might load the modules themselves and when they set
this property to true, no warning will be logged.
The context properties may also contain custom values. For example, the context.modules and
context.objects sections can declare additional conditions that control whether a module or object is
loaded depending on what properties are present.
SPA LIBRARIES
SPA plugins are loaded based on their factory-name. This is a well known name that uniquely describes the
features that the plugin should have. The context.spa-libs section provides a mapping between the
factory-name and the plugin where the factory can be found.
Factory names can contain a wildcard to group several related factories into one plugin. The plugin is
loaded from the first matching factory-name.
Example
context.spa-libs = {
audio.convert.* = audioconvert/libspa-audioconvert
avb.* = avb/libspa-avb
api.alsa.* = alsa/libspa-alsa
api.v4l2.* = v4l2/libspa-v4l2
api.libcamera.* = libcamera/libspa-libcamera
api.bluez5.* = bluez5/libspa-bluez5
api.vulkan.* = vulkan/libspa-vulkan
api.jack.* = jack/libspa-jack
support.* = support/libspa-support
video.convert.* = videoconvert/libspa-videoconvert
}
MODULES
PipeWire modules to be loaded. See libpipewire-modules(7).
context.modules = [
#{ name = MODULENAME
# ( args = { KEY = VALUE ... } )
# ( flags = [ ( ifexists ) ( nofail ) ] )
# ( condition = [ { KEY = VALUE ... } ... ] )
#}
#
]
name
Name of module to be loaded
args = { }
Arguments passed to the module
flags = [ ]
Loading flags. ifexists to only load module if it exists, and nofail to not fail PipeWire startup if
the module fails to load.
condition = [ ]
A match rule matches condition. The module is loaded only if one of the expressions in the array
matches to a context property.
CONTEXT OBJECTS
The context.objects section allows you to make some objects from factories (usually created by loading
modules in context.modules).
context.objects = [
#{ factory = <factory-name>
# ( args = { <key> = <value> ... } )
# ( flags = [ ( nofail ) ] )
# ( condition = [ { <key> = <value> ... } ... ] )
#}
]
This section can be used to make nodes or links between nodes.
factory
Name of the factory to create the object.
args = { }
Arguments passed to the factory.
flags = [ ]
Flag nofail to not fail PipeWire startup if the object fails to load.
condition = [ ]
A match rule matches condition. The object is created only if one of the expressions in the array
matches to a context property.
Example
This fragment creates a new dummy driver node, but only if core.daemon property is true:
context.objects = [
{ factory = spa-node-factory
args = {
factory.name = support.node.driver
node.name = Dummy-Driver
node.group = pipewire.dummy
priority.driver = 20000
},
condition = [ { core.daemon = true } ]
}
]
COMMAND EXECUTION
The context.exec section can be used to start arbitrary commands as part of the initialization of the
PipeWire program.
context.exec = [
#{ path = <program-name>
# ( args = "<arguments>" | [ <arg1> <arg2> ... ] )
# ( condition = [ { <key> = <value> ... } ... ] )
#}
]
path
Program to execute.
args
Arguments to the program.
condition
A match rule matches condition. The object is created only if one of the expressions in the array
matches to a context property.
Example
The following fragment executes a pactl command with the given arguments:
context.exec = [
{ path = "pactl" args = "load-module module-always-sink" }
]
MATCH RULES
Some configuration file sections contain match rules. This makes it possible to perform some action when
an object (usually a node or stream) is created/updated that matches certain properties.
The general rules object follows the following pattern:
<rules> = [
{
matches = [
# any of the following sets of properties are matched, if
# any matches, the actions are executed
{
# <key> = <value>
# all keys must match the value. ! negates. ~ starts regex.
#application.process.binary = "teams"
#application.name = "~speech-dispatcher.*"
# Absence of property can be tested by comparing to null
#pipewire.sec.flatpak = null
}
{
# more matches here...
}
...
]
actions = {
<action-name> = <action value>
...
}
}
]
Match rules are an array of rules.
A rule is always a JSON object with two keys: matches and actions. The matches key is used to define the
conditions that need to be met for the rule to be evaluated as true, and the actions key is used to
define the actions that are performed when the rule is evaluated as true.
The matches key is always a JSON array of objects, where each object defines a condition that needs to be
met. Each condition is a list of key-value pairs, where the key is the name of the property that is being
matched, and the value is the value that the property needs to have. Within a condition, all the key-
value pairs are combined with a logical AND, and all the conditions in the matches array are combined
with a logical OR.
The actions key is always a JSON object, where each key-value pair defines an action that is performed
when the rule is evaluated as true. The action name is specific to the rule and is defined by the rule’s
documentation, but most frequently you will see the update-props action, which is used to update the
properties of the matched object.
In the matches array, it is also possible to use regular expressions to match property values. For
example, to match all nodes with a name that starts with my_, you can use the following condition:
matches = [
{
node.name = "~my_.*"
}
]
The ~ character signifies that the value is a regular expression. The exact syntax of the regular
expressions is the POSIX extended regex syntax, as described in the regex (7) man page.
In addition to regular expressions, you may also use the ! character to negate a condition. For example,
to match all nodes with a name that does not start with my_, you can use the following condition:
matches = [
{
node.name = "!~my_.*"
}
]
The ! character can be used with or without a regular expression. For example, to match all nodes with a
name that is not equal to my_node, you can use the following condition:
matches = [
{
node.name = "!my_node"
}
]
The null value has a special meaning; it checks if the property is not available (or unset). To check if
a property is not set:
matches = [
{
node.name = null
}
]
To check the existence of a property, one can use the !null condition, for example:
matches = [
{
node.name = "!null"
}
{
node.name = !null # simplified syntax
}
]
To handle the 'null' string, one needs to escape the string. For example, to check if a property has the
string value 'null', use:
matches = [
{
node.name = "null"
}
]
To handle anything but the 'null' string, use:
matches = [
{
node.name = "!\"null\""
}
{
node.name = !"null" # simplified syntax
}
]
CONTEXT PROPERTIES RULES
context.properties.rules can be used to dynamically update the properties based on other properties.
A typical case is to update custom settings when running inside a VM. The cpu.vm.name is automatically
set when running in a VM with the name of the VM. A match rule can be written to set custom properties
like this:
context.properties.rules = [
{ matches = [ { cpu.vm.name = !null } ]
actions = {
update-props = {
# These overrides are only applied when running in a vm.
default.clock.min-quantum = 1024
}
}
}
}
NODE RULES
The node.rules are evaluated every time the properties on a node are set or updated. This can be used on
the server side to override client set properties on arbitrary nodes.
node.rules provides an update-props action that takes an object with properties that are updated on the
node object.
Add a node.rules section in the config file like this:
node.rules = [
{
matches = [
{
# all keys must match the value. ! negates. ~ starts regex.
client.name = "jack_simple_client"
}
]
actions = {
update-props = {
node.force-quantum = 512
}
}
}
]
Will set the node.force-quantum property of jack_simple_client to 512.
DEVICE RULES
The device.rules are evaluated every time the properties on a device are set or updated. This can be used
on the server side to override client set properties on arbitrary devices.
device.rules provides an update-props action that takes an object with properties that are updated on the
device object.
Add a device.rules section in the config file like this:
device.rules = [
{
matches = [
{
# all keys must match the value. ! negates. ~ starts regex.
device.name = ""v4l2_device.pci-0000_00_14.0-usb-0_1.2_1.0
}
]
actions = {
update-props = {
device.description = "My Webcam"
}
}
}
]
Will set the device.description property of the device with the given device.name to 'My Webcam'.
AUTHORS
The PipeWire Developers <https://gitlab.freedesktop.org/pipewire/pipewire/issues>; PipeWire is available
from <https://pipewire.org>
SEE ALSO
pipewire(1), pw-mon(1), libpipewire-modules(7) pipewire-pulse.conf(5) pipewire-client.conf(5)