pulseaudio
The PulseAudio Sound System
see also :
pacmd
Synopsis
pulseaudio
[options]
pulseaudio
--help
pulseaudio
--version
pulseaudio
--dump-conf
pulseaudio
--dump-modules
pulseaudio
--dump-resample-methods
pulseaudio
--cleanup-shm
pulseaudio
--start
pulseaudio
--kill
pulseaudio
--check
add an example, a script, a trick and tips
examples
source
How do I recompile libav on ubuntu 12.04 without breaking anything
Looks like it has compiled properly like so:
sudo ./configure --prefix="/home/j/projects/avconv-source/build" --enable-gpl --enable-libmp3lame --enable-libpulse --enable-libx264 --enable-x11grab
source
Is it possible to route different applications to different audio outputs with Pulse Audio?
Try Ear Candy. It is not only possible to switch
between outputs when they're attached, but also to route several
programs to other outputs as you're looking for (and lots of
other small improvements).
source
Set device for program in PulseAudio?
I don't know if there is a setting or configuration file for this
anywhere but it can be done with environment variables. I've
based my answer on this entry in the PulseAudio FAQ about setting the
recording source. I've tried this with output (a sink in
PulseAudio) but it should work for both input and ouput.
The first step is to get the internal name of the source and sink
that you want to use. To do that you need to use the pactl
list command. That command will return a pile of data, but
the following will list just the source names:
LANG=C pactl list | grep -A2 'Source #' | grep 'Name: ' | cut -d" " -f2
That list will probably include the names for both regular
sources and PulseAudio's monitor sources (which on my system have
"monitor" in the name). You'll want to use the regular source
name of the device you want to target.
You can do the same thing to get the sink names:
LANG=C pactl list | grep -A2 'Sink #' | grep 'Name: ' | cut -d" " -f2
Once you've got the names you can run something like the
following from your terminal:
PULSE_SINK=<sink_name> PULSE_SOURCE=<source_name> <command_to_run_skype>
Of course, if you want to run this from a menu you'll probably
need to create a shell script and use that instead of the default
command. Something like this should work:
#!/bin/sh
set PULSE_SINK <sink_name>
set PULSE_SOURCE <source_name>
<command_to_run_skype>
source
Prevent applications to control master volume on Linux
This Gentoo wiki article might apply here : PulseAudio per-application volume control :
PulseAudio supports per-application volume control, but by
default this doesn't do much as you can only control these
volumes from the pulseaudio volume control utility. Meaning
that in an application like Audacious, when the output device
is set to PulseAudio, and the volume control is set to
hardware, it will adjust the master volume control, not the
per-application volume control.
To fix this behavior, set the following in
/etc/pulse/daemon.conf
flat-volumes = no
Now whenever Audacious goes to adjust the volume, it will
adjust the audacious only volume and thus you wont have
multiple applications fighting over the master volume control.
source
Limit PulseAudio volume to prevent overdrive
I had to set flat-volumes = no in
/etc/pulse/daemon.conf in Fedora to stop apps from
screwing with volumes. Don't forget to restart PulseAudio after
the change.
source
Does Linux support audio output via USB?
Yes. (However not all USB audio cards are compatible with all
systems.)
I'm not sure what you mean by "out of the box" (which box, the
computer or the USB sound card...)
According to Linux-Usb.org as long as "You need to turn on the
Sound card support kernel option, which is in the Sound section.
You will then be able to turn on the USB Audio support option in
the normal USB section."
source
Changing default audio device in Pulseaudio
PulseAudio Device Chooser (padevchooser)?
source
Reconfigure line-in as analog-out
I just manage to do this on my laptopt, using the mic input
instead of line-in.
I did it by following the steps on this
AskUbuntu question
I just had to download HDA Analyzer and run it as root:
wget -O run.py http://www.alsa-project.org/hda-analyzer.py
sudo python run.py
Locate the right PIN node (more details about it on askubuntu)
uncheck IN and check OUT.
Click on export to save a python script that will make this same
changes when run, then add it somwhere on your startup scripts.
I manage to get sound out of my mic jack, but it wasn't pretty.
You'll probably have it better since you're using line-in instead
of mic.
source
Why does Pulseaudio selectively detect my sound hardware?
I took a stab at the problem, and randomyl came up with a
solution.
Curious about which processes were running, and wanting to start
fresh, I ran
$>ps aux | grep pulse
and then killed the first process that looked related to pulse
audio
/usr/bin/pulseaudio --start --log-target=syslog
Upon killing the process, which was running as my local user
anyways, my volume indicator icon returned to normal, as did
sounds. So technically the problem is fixed, but can anyone
elaborate on what may have been causing it, and why killing the
pulseaudio process restored sound...?
source
Pulseaudio is no longer working in Debian Squeeze: 'Failed to open module "module-combine-sink": file not found'
Looks like the device drivers are not loading for the sound card.
Try re-configuring alsa, alsactl init and reboot.
EDIT: From your reply it sounds like the kernel
package was updated before the crash, and now the new kernel or
alsa-base package is giving you problems. There are a bunch of open bugs specific to Intel HD Audio
driver.
My recommendation is to reboot and select the previous kernel.
You may need to do run altactl init again, but it
should work.
The other option (which is what I would do) is install the
official driver from RealTek.
description
PulseAudio is a
networked low-latency sound server for Linux, POSIX and
Windows systems.
options
-h |
--help
Show help.
--version
Show version information.
--dump-conf
Load the daemon configuration
file daemon.conf (see below), parse remaining
configuration options on the command line and dump the
resulting daemon configuration, in a format that is
compatible with daemon.conf.
--dump-modules
List available loadable
modules. Combine with -v for a more elaborate
listing.
--dump-resample-methods
List available audio
resamplers.
--cleanup-shm
Identify stale PulseAudio POSIX
shared memory segments in /dev/shm and remove them if
possible. This is done implicitly whenever a new daemon
starts up or a client tries to connect to a daemon. It
should normally not be necessary to issue this command by
hand. Only available on systems with POSIX shared memory
segments implemented via a virtual file system mounted to
/dev/shm (e.g. Linux).
--start
Start PulseAudio if it is not
running yet. This is different from starting PulseAudio
without --start which would fail if PA is already
running. PulseAudio is guaranteed to be fully initialized
when this call returns. Implies --daemon.
-k | --kill
Kill an already running
PulseAudio daemon of the calling user (Equivalent to sending
a SIGTERM).
--check
Return 0 as return code when
the PulseAudio daemon is already running for the calling
user, or non-zero otherwise. Produces no output on the
console except for errors to stderr.
--system[=BOOL]
Run as system-wide instance
instead of per-user. Please note that this disables certain
features of PulseAudio and is generally not recommended
unless the system knows no local users (e.g. is a thin
client). This feature needs special configuration and a
dedicated UNIX user set up. It is highly recommended to
combine this with --disallow-module-loading (see
below).
-D |
--daemonize[=BOOL]
Daemonize after startup, i.e.
detach from the terminal.
--fail[=BOOL]
Fail startup when any of the
commands specified in the startup script default.pa
(see below) fails.
--high-priority[=BOOL]
Try to acquire a high Unix nice
level. This will only succeed if the calling user has a
non-zero RLIMIT_NICE resource limit set (on systems that
support this), or we’re called SUID root (see below),
or we are configure to be run as system daemon (see
--system above). It is recommended to enable this,
since it is only a negligible security risk (see below).
--realtime[=BOOL]
Try to acquire a real-time
scheduling for PulseAudio’s I/O threads. This will
only succeed if the calling user has a non-zero
RLIMIT_RTPRIO resource limit set (on systems that support
this), or we’re called SUID root (see below), or we
are configure to be run as system daemon (see
--system above). It is recommended to enable this
only for trusted users, since it is a major security risk
(see below).
--disallow-module-loading[=BOOL]
Disallow module loading after
startup. This is a security feature since it disallows
additional module loading during runtime and on user
request. It is highly recommended when --system is
used (see above). Note however, that this breaks certain
features like automatic module loading on hot plug.
--exit-idle-time=SECS
Terminate the daemon when idle
and the specified number of seconds passed.
--scache-idle-time=SECS
Unload autoloaded samples from
the cache when the haven’t been used for the specified
number of seconds.
--log-level[=LEVEL]
If an argument is passed, set
the log level to the specified value, otherwise increase the
configured verbosity level by one. The log levels are
numerical from 0 to 4, corresponding to error,
warn, notice, info, debug.
Default log level is notice, i.e. all log messages
with lower log levels are printed: error,
warn, notice.
-v
Increase the configured verbosity level by one (see
--log-level above). Specify multiple times to
increase log level multiple times.
--log-target={auto,syslog,stderr,file:PATH}
Specify the log target. If set
to auto (which is the default), then logging is
directed to syslog when --daemonize is passed,
otherwise to STDERR. If set to file:PATH, logging is
directed to the file indicated by PATH.
--log-meta[=BOOL]
Show source code location in
log messages.
--log-time[=BOOL]
Show timestamps in log
messages.
--log-backtrace=FRAMES
When FRAMES is greater than 0,
log for each message a stack trace up to the number of
specified stack frames.
--p |
--dl-search-path=PATH
Set the search path for dynamic
shared objects (plugins).
--resample-method=METHOD
Use the specified resampler by
default (See --dump-resample-methods above for
possible values).
--use-pid-file[=BOOL]
Create a PID file. If this
options is disabled it is possible to run multiple sound
servers per user.
--no-cpu-limit[=BOOL]
Do not install CPU load limiter
on platforms that support it. By default, PulseAudio will
terminate itself when it notices that it takes up too much
CPU time. This is useful as a protection against system
lockups when real-time scheduling is used (see below).
Disabling this meachnism is useful when debugging PulseAudio
with tools like valgrind(1) which slow down
execution.
--disable-shm[=BOOL]
PulseAudio clients and the
server can exchange audio data via POSIX shared memory
segments (on systems that support this). If disabled
PulseAudio will communicate exclusively over sockets. Please
note that data transfer via shared memory segments is always
disabled when PulseAudio is running with --system
enabled (see above).
-L |
--load="MODULE ARGUMENTS"
Load the specified plugin
module with the specified arguments.
-F |
--file=FILENAME
Run the specified script on
startup. May be specified multiple times to specify multiple
scripts to be run in order. Combine with -n to
disable loading of the default script default.pa (see
below).
-C
Open a command interpreter on STDIN/STDOUT after
startup. This may be used to configure PulseAudio
dynamically during runtime. Equivalent to
--load=module-cli.
-n
Don’t load default script file default.pa
(see below) on startup. Useful in conjunction with -C
or --file.
environment variables
The PulseAudio client libraries check for the existance of the
following environment variables and change their local
configuration accordingly:
$PULSE_SERVER: the server string specifying the server to
connect to when a client asks for a sound server connection and
doesn’t explicitly ask for a specific server.
$PULSE_SINK: the symbolic name of the sink to connect to
when a client creates a playback stream and doesn’t explicitly
ask for a specific sink.
$PULSE_SOURCE: the symbolic name of the source to connect
to when a client creates a record stream and doesn’t explicitly
ask for a specific source.
$PULSE_BINARY: path of PulseAudio executable to run when
server auto-spawning is used.
$PULSE_CLIENTCONFIG: path of file that shall be read
instead of client.conf (see above) for client
configuration.
These environment settings take precedence -- if set -- over the
configuration settings from client.conf (see above).
files
~/.config/pulse/daemon.conf,
/etc/pulse/daemon.conf: configuration settings for the
PulseAudio daemon. If the version in the user’s home directory
does not exist the global configuration file is loaded. See
pulse-daemon.conf(5) for more information.
~/.config/pulse/default.pa, /etc/pulse/default.pa:
the default configuration script to execute when the PulseAudio
daemon is started. If the version in the user’s home directory
does not exist the global configuration script is loaded. See
default.pa(5) for more information.
~/.config/pulse/client.conf,
/etc/pulse/client.conf: configuration settings for
PulseAudio client applications. If the version in the user’s home
directory does not exist the global configuration file is loaded.
See pulse-client.conf(5) for more information.
real-time and high-priority scheduling
To minimize the risk of drop-outs during playback it is
recommended to run PulseAudio with real-time scheduling if the
underlying platform supports it. This decouples the scheduling
latency of the PulseAudio daemon from the system load and is thus
the best way to make sure that PulseAudio always gets CPU time
when it needs it to refill the hardware playback buffers.
Unfortunately this is a security risk on most systems, since
PulseAudio runs as user process, and giving realtime scheduling
priviliges to a user process always comes with the risk that the
user misuses it to lock up the system -- which is possible since
making a process real-time effectively disables preemption.
To minimize the risk PulseAudio by default does not enable
real-time scheduling. It is however recommended to enable it on
trusted systems. To do that start PulseAudio with
--realtime (see above) or enabled the appropriate option
in daemon.conf. Since acquiring realtime scheduling is a
priviliged operation on most systems, some special changes to the
system configuration need to be made to allow them to the calling
user. Two options are available:
On newer Linux systems the system resource limit RLIMIT_RTPRIO
(see setrlimit(2) for more information) can be used to
allow specific users to acquire real-time scheduling. This can be
configured in /etc/security/limits.conf, a resource limit
of 9 is recommended.
Alternatively, the SUID root bit can be set for the PulseAudio
binary. Then, the daemon will drop root priviliges immediately on
startup, however retain the CAP_NICE capability (on systems that
support it), but only if the calling user is a member of the
pulse-rt group (see above). For all other users all
capababilities are dropped immediately. The advantage of this
solution is that the real-time priviliges are only granted to the
PulseAudio daemon -- not to all the user’s processes.
Alternatively, if the risk of locking up the machine is
considered too big to enable real-time scheduling, high-priority
scheduling can be enabled instead (i.e. negative nice level).
This can be enabled by passing --high-priority (see above)
when starting PulseAudio and may also be enabled with the
approriate option in daemon.conf. Negative nice levels can
only be enabled when the appropriate resource limit RLIMIT_NICE
is set (see setrlimit(2) for more information), possibly
configured in /etc/security/limits.conf. A resource limit
of 31 (corresponding with nice level -11) is recommended.
signals
SIGINT, SIGTERM: the PulseAudio daemon will shut down
(Same as --kill).
SIGHUP: dump a long status report to STDOUT or syslog,
depending on the configuration.
SIGUSR1: load module-cli, allowing runtime reconfiguration
via STDIN/STDOUT.
SIGUSR2: load module-cli-protocol-unix, allowing runtime
reconfiguration via a AF_UNIX socket. See pacmd(1) for
more information.
unix groups and users
Group pulse-rt: if the PulseAudio binary is marked SUID
root, then membership of the calling user in this group decides
whether real-time and/or high-priority scheduling is enabled.
Please note that enabling real-time scheduling is a security risk
(see below).
Group pulse-access: if PulseAudio is running as a system
daemon (see --system above) access is granted to members
of this group when they connect via AF_UNIX sockets. If
PulseAudio is running as a user daemon this group has no meaning.
User pulse, group pulse: if PulseAudio is running
as a system daemon (see --system above) and is started as
root the daemon will drop priviliges and become a normal user
process using this user and group. If PulseAudio is running as a
user daemon this user and group has no meaning.
see also
pulse-daemon.conf,
default.pa, pulse-client.conf,
pacmd
authors
The PulseAudio
Developers <pulseaudio-discuss (at) lists (dot)
freedesktop (dot) org>; PulseAudio is available from
http://pulseaudio.org/