Amarok not working with phonon + gstreamer + pulseaudio + kde5

[jerith666]

Issue description

I can't seem to make Amarok play any music. The initial symptom was that PHONON_BACKEND_DEBUG=3 PHONON_SUBSYSTEM_DEBUG=1 amarok --debug printed:

"Warning: You do not seem to have the base GStreamer plugins installed.
All audio and video support has been disabled"
Phonon::GStreamer::Backend: Failed to initialize GStreamer

... the play controls looked to be drawn incompletely (only a play button, no skip fwd/back, etc.), and the phonon settings dialog was completely empty.

After some digging, I hit upon the distinction between GST_PLUGIN_SYSTEM_PATH and GST_PLUGIN_SYSTEM_PATH_1_0. Only the latter was set in my environment, because I'm using kde5 and its nix expression (at nixos/modules/services/x11/desktop-managers/kde5.nix) only sets that. However, amarok looked to be wanting the former since it depends on gstreamer-0.10:

$ nix-store -q --graph $(dirname $(dirname $(readlink -e $(type -p amarok)))) | grep 'gst.*->'
"/nix/store/vf7n11vh8sksa70gp3l2bsvv3h3j0f3p-gst-plugins-base-0.10.36" -> "/nix/store/i8r91xw4b5bg0349kdc7hr4pc63cnxqf-qt-4.8.7" [color = "red"];
"/nix/store/vj9jznlp4y6s2c3c8vnc7him20i6iiim-gstreamer-0.10.36" -> "/nix/store/i8r91xw4b5bg0349kdc7hr4pc63cnxqf-qt-4.8.7" [color = "green"];
"/nix/store/vj9jznlp4y6s2c3c8vnc7him20i6iiim-gstreamer-0.10.36" -> "/nix/store/vf7n11vh8sksa70gp3l2bsvv3h3j0f3p-gst-plugins-base-0.10.36" [color = "burlywood"];

So I added this to configuration.nix (cribbed from kde4.nix):

environment.profileRelativeEnvVars = {
  GST_PLUGIN_SYSTEM_PATH = [ "/lib/gstreamer-0.10" ];
};

and added gst_all.gstPluginsBase to environment.systemPackages. This instead yielded a crash in Phonon::Gstreamer::MediaNode::linkMediaNodeList. Adding gst_all.gstPluginsGood gst_all.gstPluginsBad gst_all.gstPluginsUgly didn't help. Flailing some more, I added gstreamer; that turned the crash into a hang: the amarok window appears but does not draw completely.

At this point I think that the problem is that pkgs/development/libraries/phonon/backends/gstreamer.nix depends on gstreamer 1.x, while amarok depends on gstreamer 0.x. I tried tweaking the former to use gst_all instead of gst_all_1, but that produced a build failure:

-- Checking for module 'gstreamer-1.0'
--   Package 'gstreamer-1.0' not found

It doesn't look easily possible to build amarok against gst_all_1, since its dependency comes indirectly via qt.

I'm hoping for some help from @ttuegel, whose name is all over the relevant git logs. :)

Technical details

• System: 16.09.git.53c0a7d (Flounder) (based on nixos-unstable @ 453086a)
• Nix version: nix-env (Nix) 1.11.2
• Nixpkgs version: 16.09.git.5431facM

[joelmo]

I am not a amarok user but I see same issue here, actually not anything but the interface appears to be working.

[jerith666]

There is another fix needed to make the collection work with MySQL / MariaDB: #16578

[jerith666]

Just an update on the current state: seems to be about the same as before. On current nixos-unstable (@2839b101f9), PHONON_BACKEND_DEBUG=3 PHONON_SUBSYSTEM_DEBUG=1 amarok --debug still prints:

amarok:     BEGIN: void EngineController::initializePhonon() 
PHONON-GST       [WARNING] "Warning: You do not seem to have the base GStreamer plugins installed.
          All audio and video support has been disabled" 
PHONON-GST       [WARNING] "Warning: You do not seem to have the base GStreamer plugins installed.
          All audio and video support has been disabled" 
PHONON-GST       Using GStreamer 0.10.36 
Phonon::GStreamer::Backend: Failed to initialize GStreamer
PHONON-GST       [WARNING] Backend class 2 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 3 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
WARNING: Phonon::createPath: Cannot connect  Phonon::MediaObject ( no objectName ) to  Phonon::AudioDataOutput ( no objectName ). 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
WARNING: Phonon::createPath: Cannot connect  Phonon::MediaObject ( no objectName ) to  Phonon::AudioOutput ( no objectName ). 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 1 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 1 is not going to be created because GStreamer init failed. 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
amarok:       [EngineController] Tick Interval (actual):  100 
PHONON-GST       [WARNING] Backend class 0 is not going to be created because GStreamer init failed. 
amarok:     END__: void EngineController::initializePhonon() [Took: 0.076s] 

... but the UI is responsive. With the environment.profileRelativeEnvVars and environment.systemPackages changes from the description reapplied, amarok still hangs on startup.

[jerith666]

It looks like amarok has been removed in 6c317b6 / #32927. There is still amarok-kf5 (#26436), but I haven't tested that.

However, in the course of researching it, I discovered https://www.clementine-player.org/, which is in nixpkgs and after a bit of testing seems to do the main things I used amarok for. So, if others are running into this problem, I recommend trying clementine as a replacement.

[Ekleog]

(triage) If I understand correctly, the problem can no longer be experienced due to amarok being removed?

[jerith666]

Yes, I think so; closing.