Quod Libet currently supports GStreamer and Xine as an audio backend. The
default backend can be changed in
~/.quodlibet/config by setting the
backend option (
gstbe = GStreamer,
xinebe = Xine,
no backend). Make sure Quod Libet isn’t running while you edit the file.
Quod Libet now supports JACK via Gstreamer’s
jackaudiosink, if available.
To select this, check the Use JACK for playback if available button
in the Player tab of Preferences.
There’s also an option to auto-connect (wire up) the Quod Libet output
to JACK output sinks (e.g. system devices) or not.
It’s possible to attach a custom GStreamer pipeline to the player backend
under File → Preferences → Playback → Output Pipeline. The
pipeline syntax is equivalent to what is used in the gst-launch utility.
man gst-launch for further information and examples.
In case the custom pipeline doesn’t contain an audio sink, Quod Libet will add a default one for you.
In case you are interested in which GStreamer elements and audio formats
are used in the current pipeline, start Quod Libet in debug mode
quodlibet --debug), go to File → Preferences → Playback and
press the Print Pipeline button. It will print the whole pipeline used
for the current active song to stdout.
For debugging GStreamer related issues see the official GStreamer docs: Running and debugging GStreamer Applications
Gstreamer supports gapless playback for all common formats except MP3. See the following bug report for more information: https://bugzilla.gnome.org/show_bug.cgi?id=620323
Selecting an Output Device
If you want QL to output to a different device you have to pass the device option to the sink by setting a custom pipeline. In case of pulseaudio you can get a list of available devices by executing:
#!/usr/bin/env python2 import gi gi.require_version("Gst", "1.0") from gi.repository import Gst Gst.init(None) dm = Gst.DeviceMonitor() dm.start() for device in dm.get_devices(): if device.get_device_class() == "Audio/Sink": props = device.get_properties() element = device.create_element(None) type_name = element.get_factory().get_name() device_name = element.props.device print "%s device=%r" % (type_name, device_name) dm.stop()
which should give you something like:
which you can use as is, as a custom pipeline.
The Xine backend needs either xine-lib 1.1.x or xine-lib 1.2.x. Since most distributions make QL only depend on GStreamer, you might have to install xine-lib manually (libxine1, lixine2 in Debian/Ubuntu).
To enable the backend, set the
backend option in the
config file to
"xinebe" while QL isn’t running.