pulse-daemon.conf - PulseAudio daemon configuration file
The PulseAudio sound server reads configuration directives from a configuration
file on startup. If the per-user file ~/.config/pulse/daemon.conf
exists, it is used, otherwise the system configuration file
is used. In addition to those main files,
configuration directives can also be put in files under directories
Those files have to have the .conf file name extension, but otherwise the file
names can be chosen freely. The files under daemon.conf.d are processed in
alphabetical order. In case the same option is set in multiple files, the last
file to set an option overrides earlier files. The main daemon.conf file is
processed first, so options set in files under daemon.conf.d override the main
Please note that the server also reads a configuration script on startup. See
The configuration file is a simple collection of variable declarations. If the
configuration file parser encounters either ; or # it ignores the rest of the
line until its end.
For the settings that take a boolean argument the values true
are equivalent, resp. false
- daemonize= Daemonize after startup. Takes a boolean value,
defaults to no. The --daemonize command line option takes
- fail= Fail to start up if any of the directives in the
configuration script default.pa fail. Takes a boolean argument,
defaults to yes. The --fail command line option takes
- allow-module-loading= Allow/disallow module loading after startup.
This is a security feature that if disabled makes sure that no further
modules may be loaded into the PulseAudio server after startup completed. It
is recommended to disable this when system-instance is enabled.
Please note that certain features like automatic hot-plug support will not
work if this option is enabled. Takes a boolean argument, defaults to
yes. The --disallow-module-loading command line option takes
- allow-exit= Allow/disallow exit on user request. Defaults to
- resample-method= The resampling algorithm to use. Use one of
src-sinc-fastest, src-zero-order-hold, src-linear,
trivial, speex-float-N, speex-fixed-N, ffmpeg,
soxr-mq, soxr-hq, soxr-vhq. See the documentation of
libsamplerate and speex for explanations of the different src- and speex-
methods, respectively. The method trivial is the most basic algorithm
implemented. If you're tight on CPU consider using this. On the other hand
it has the worst quality of them all. The Speex resamplers take an integer
quality setting in the range 0..10 (bad...good). They exist in two flavours:
fixed and float. The former uses fixed point numbers, the
latter relies on floating point numbers. On most desktop CPUs the float
point resampler is a lot faster, and it also offers slightly better quality.
The soxr-family methods are based on libsoxr, a resampler library from the
SoX sound processing utility. The mq variant has the best performance of the
three. The hq is more expensive and, according to SoX developers, is
considered the best choice for audio of up to 16 bits per sample. The vhq
variant has more precision than hq and is more suitable for larger samples.
The Soxr resamplers generally offer better quality at less CPU compared to
other resamplers, such as speex. The downside is that they can add a
significant delay to the output (usually up to around 20 ms, in rare cases
more). See the output of dump-resample-methods for a complete list of
all available resamplers. Defaults to speex-float-1. The
--resample-method command line option takes precedence. Note that
some modules overwrite or allow overwriting of the resampler to use.
- avoid-resampling= If set, try to configure the device to avoid
resampling. This only works on devices which support reconfiguring their
rate, and when no other streams are already playing or capturing audio. The
device will also not be configured to a rate less than the default and
alternate sample rates.
- enable-remixing= If disabled never upmix or downmix channels to
different channel maps. Instead, do a simple name-based matching only.
Defaults to yes.
- remixing-use-all-sink-channels= If enabled, use all sink channels
when remixing. Otherwise, remix to the minimal set of sink channels needed
to reproduce all of the source channels. (This has no effect on LFE
remixing.) Defaults to yes.
- enable-lfe-remixing= If disabled when upmixing or downmixing ignore
LFE channels. When this option is disabled the output LFE channel will only
get a signal when an input LFE channel is available as well. If no input LFE
channel is available the output LFE channel will always be 0. If no output
LFE channel is available the signal on the input LFE channel will be
ignored. Defaults to no.
- lfe-crossover-freq= The crossover frequency (in Hz) for the LFE
filter. Set it to 0 to disable the LFE filter. Defaults to 0.
- use-pid-file= Create a PID file in the runtime directory
($XDG_RUNTIME_DIR/pulse/pid). If this is enabled you may use commands
like --kill or --check. If you are planning to start more than
one PulseAudio process per user, you better disable this option since it
effectively disables multiple instances. Takes a boolean argument, defaults
to yes. The --use-pid-file command line option takes
- cpu-limit= If disabled do not install the CPU load limiter, even on
platforms where it is supported. This option is useful when
debugging/profiling PulseAudio to disable disturbing SIGXCPU signals. Takes
a boolean argument, defaults to no. The --no-cpu-limit command
line argument takes precedence.
- system-instance= Run the daemon as system-wide instance, requires
root privileges. Takes a boolean argument, defaults to no. The
--system command line argument takes precedence.
- local-server-type= Please don't use this option if you don't have
to! This option is currently only useful when you want D-Bus clients to use
a remote server. This option may be removed in future versions. If you only
want to run PulseAudio in the system mode, use the system-instance
option. This option takes one of user, system or none
as the argument. This is essentially a duplicate for the
system-instance option. The difference is the none option,
which is useful when you want to use a remote server with D-Bus clients. If
both this and system-instance are defined, this option takes
precedence. Defaults to whatever the system-instance is set.
- enable-shm= Enable data transfer via POSIX or memfd shared memory.
Takes a boolean argument, defaults to yes. The --disable-shm
command line argument takes precedence.
- enable-memfd=. Enable memfd shared memory. Takes a boolean
argument, defaults to yes.
- shm-size-bytes= Sets the shared memory segment size for the daemon,
in bytes. If left unspecified or is set to 0 it will default to some
system-specific default, usually 64 MiB. Please note that usually there is
no need to change this value, unless you are running an OS kernel that does
not do memory overcommit.
- lock-memory= Locks the entire PulseAudio process into memory. While
this might increase drop-out safety when used in conjunction with real-time
scheduling this takes away a lot of memory from other processes and might
hence considerably slow down your system. Defaults to no.
- flat-volumes= Enable 'flat' volumes, i.e. where possible let the
sink volume equal the maximum of the volumes of the inputs connected to it.
Takes a boolean argument, defaults to yes.
- high-priority= Renice the daemon after startup to become a
high-priority process. This a good idea if you experience drop-outs during
playback. However, this is a certain security issue, since it works when
called SUID root only, or RLIMIT_NICE is used. root is dropped immediately
after gaining the nice level on startup, thus it is presumably safe. See
pulseaudio(1) for more information. Takes a boolean argument,
defaults to yes. The --high-priority command line option takes
- realtime-scheduling= Try to acquire SCHED_FIFO scheduling for the
IO threads. The same security concerns as mentioned above apply. However, if
PA enters an endless loop, realtime scheduling causes a system lockup. Thus,
realtime scheduling should only be enabled on trusted machines for now.
Please note that only the IO threads of PulseAudio are made real-time. The
controlling thread is left a normally scheduled thread. Thus enabling the
high-priority option is orthogonal. See pulseaudio(1) for more
information. Takes a boolean argument, defaults to yes. The
--realtime command line option takes precedence.
- realtime-priority= The realtime priority to acquire, if
realtime-scheduling is enabled. Note: JACK uses 10 by default, 9 for
clients. Thus it is recommended to choose the PulseAudio real-time
priorities lower. Some PulseAudio threads might choose a priority a little
lower or higher than the specified value. Defaults to 5.
- nice-level= The nice level to acquire for the daemon, if
high-priority is enabled. Note: on some distributions X11 uses -10 by
default. Defaults to -11.
- exit-idle-time= Terminate the daemon after the last client quit and
this time in seconds passed. Use a negative value to disable this feature.
Defaults to 20. The --exit-idle-time command line option takes
- scache-idle-time= Unload autoloaded sample cache entries after
being idle for this time in seconds. Defaults to 20. The
--scache-idle-time command line option takes precedence.
- dl-search-path= The path where to look for dynamic shared objects
(DSOs/plugins). You may specify more than one path separated by colons. The
default path depends on compile time settings. The --dl-search-path
command line option takes precedence.
- default-script-file= The default configuration script file to load.
Specify an empty string for not loading a default script file. The default
behaviour is to load ~/.config/pulse/default.pa, and if that file
does not exist fall back to the system wide installed version
/etc/pulse/default.pa. If run in system-wide mode the file
/etc/pulse/system.pa is used instead. If -n is passed on the
command line or default-script-file= is disabled the default
configuration script is ignored.
- load-default-script-file= Load the default configuration script
file as specified in default-script-file=. Defaults to
- log-target= The default log target. Use either stderr,
syslog, journal (optional), auto, file:PATH or
newfile:PATH. On traditional systems auto is equivalent to
syslog. On systemd-enabled systems, auto is equivalent to
journal, in case daemonize is enabled, and to stderr
otherwise. If set to file:PATH, logging is directed to the file
indicated by PATH. newfile:PATH is otherwise the same as
file:PATH, but existing files are never overwritten. If the specified
file already exists, a suffix is added to the file name to avoid
overwriting. Defaults to auto. The --log-target command line
option takes precedence.
- log-level= Log level, one of debug, info,
notice, warning, error. Log messages with a lower log
level than specified here are not logged. Defaults to notice. The
--log-level command line option takes precedence. The -v
command line option might alter this setting.
- log-meta= With each logged message log the code location the
message was generated from. Defaults to no.
- log-time= With each logged message log the relative time since
startup. Defaults to no.
- log-backtrace= When greater than 0, with each logged message log a
code stack trace up the specified number of stack frames. Defaults to
for more information. Set to -1 if PulseAudio shall not
touch the resource limit. Not all resource limits are available on all
- rlimit-as Defaults to -1.
- rlimit-rss Defaults to -1.
- rlimit-core Defaults to -1.
- rlimit-data Defaults to -1.
- rlimit-fsize Defaults to -1.
- rlimit-nofile Defaults to 256.
- rlimit-stack Defaults to -1.
- rlimit-nproc Defaults to -1.
- rlimit-locks Defaults to -1.
- rlimit-sigpending Defaults to -1.
- rlimit-msgqueue Defaults to -1.
- rlimit-memlock Defaults to 16 KiB. Please note that the JACK client
libraries may require more locked memory.
- rlimit-nice Defaults to 31. Please make sure that the default nice
level as configured with nice-level fits in this resource limit, if
high-priority is enabled.
- rlimit-rtprio Defaults to 9. Please make sure that the default
real-time priority level as configured with realtime-priority= fits
in this resource limit, if realtime-scheduling is enabled. The JACK
client libraries require a real-time priority of 9 by default.
- rlimit-rttime Defaults to 1000000.
Most drivers try to open the audio device with these settings and then fall back
to lower settings. The default settings are CD quality: 16bit native endian, 2
channels, 44100 Hz sampling.
- default-sample-format= The default sampling format. Specify one of
u8, s16le, s16be, s24le, s24be,
s24-32le, s24-32be, s32le, s32be
float32le, float32be, ulaw, alaw. Depending on
the endianness of the CPU the formats s16ne, s16re,
s24ne, s24re, s24-32ne, s24-32re, s32ne,
s32re, float32ne, float32re (for native, resp. reverse
endian) are available as aliases.
- default-sample-rate= The default sample frequency.
- default-sample-channels The default number of channels.
- default-channel-map The default channel map.
- alternate-sample-rate The alternate sample frequency. Sinks and
sources will use either the default-sample-rate value or this alternate
value, typically 44.1 or 48kHz. Switching between default and alternate
values is enabled only when the sinks/sources are suspended. This option is
ignored in passthrough mode where the stream rate will be used. If set to
the same value as the default sample rate, this feature is disabled.
Some hardware drivers require the hardware playback buffer to be subdivided into
several fragments. It is possible to change these buffer metrics for machines
with high scheduling latencies. Not all possible values that may be configured
here are available in all hardware. The driver will find the nearest setting
supported. Modern drivers that support timer-based scheduling ignore these
- default-fragments= The default number of fragments. Defaults to
- default-fragment-size-msec=The duration of a single fragment.
Defaults to 25ms (i.e. the total buffer is thus 100ms long).
With the flat volume feature enabled, the sink HW volume is set to the same
level as the highest volume input stream. Any other streams (with lower
volumes) have the appropriate adjustment applied in SW to bring them to the
correct overall level. Sadly hardware mixer changes cannot be timed accurately
and thus this change of volumes can sometimes cause the resulting output sound
to be momentarily too loud or too soft. So to ensure SW and HW volumes are
applied concurrently without any glitches, their application needs to be
synchronized. The sink implementation needs to support deferred volumes. The
following parameters can be used to refine the process.
- enable-deferred-volume= Enable deferred volume for the sinks that
support it. This feature is enabled by default.
- deferred-volume-safety-margin-usec= The amount of time (in usec) by
which the HW volume increases are delayed and HW volume decreases are
advanced. Defaults to 8000 usec.
- deferred-volume-extra-delay-usec= The amount of time (in usec) by
which HW volume changes are delayed. Negative values are also allowed.
Defaults to 0.
The PulseAudio Developers <pulseaudio-discuss (at) lists (dot) freedesktop
(dot) org>; PulseAudio is available from http://pulseaudio.org/