Unless you disable audio forwarding, you can start and stop it from the system tray at any time.
The client and server will negotiate which codec to use. The most widely tested and supported codecs are opus, vorbis, flac and mp3.
Unlike screen updates which are sent as discrete events, audio compression processes the operating system’s audio stream and so this is a continuous process which will take up a little bit of CPU and bandwidth.
If you want to turn off speaker forwarding, use the option
speaker=off
in your system wide xpra.conf
(to
disable it globally) or in the per-user configuration file, or on the
command line
Audio information displayed on session info (with speaker enabled
and running and microphone disabled):
A Linux client’s pavucontrol showing the Xpra application
connected to the local pulseaudio server:
pavucontrol running within the xpra session (“on the server”),
showing xpra recording the session’s audio:
speaker=on|off|disabled
/
microphone=on|off|disabled
: audio input and output
forwarding control: on will start the forwarding as soon as the
connection is established, off will require the user to enable
it via the menu, disabled will prevent it from being used and the menu
entry will be disabled * speaker-codec=CODEC
/
microphone-codec=CODEC
: Specify the codec(s) to use for
audio output (speaker) or input (microphone). This parameter can be
specified multiple times and the order in which the codecs are specified
defines the preferred cod ec order. Use the special value ’help’ to get
a list of options. When unspecified, all the available codecs are
allowed and the first one is used. *
sound-source=PLUGIN[:OPTIONS]
: Specifies the GStreamer
sound plugin used for capturing the sound stream. This affects “speaker
forwarding” on the server, and “microphone” forwarding on the client. To
get a list of options use the special value h elp. It is also
possible to specify plugin options using the form
"--sound-source=SOURCE:name1=value1,name2=value2,etc"
, ie:
"--sound-source=pulse:device=device.alsa_input.pci-0000_00_14.2.analog-stereo"
XPRA_PULSEAUDIO_DEVICE_NAME
to use a specific device if
there is more than one device to choose from (can happen when using an
existing pulseaudio server with more than one output device attached) *
XPRA_SOUND_QUEUE_TIME
can be used to control the default
amount of buffering by the receiver *
XPRA_SOUND_GRACE_PERIOD
(defaults to 2000
, in
milliseconds) errors will be ignored during this grace period after
starting audio forwarding, to allow the audio forwarding buffer to
settle down * XPRA_SOUND_SINK
: the default sink to use
(normally auto-detected)