mpd and pulseaudio

[paulj]

I have a recently installed and now fully up to date to the latest profile Thinkpad X270. I have been a user of amarok for many years (despite frustrations with cover search and so on), but with the recent masking of the current release, and also not much visible development of the Qt5 version, I have decided to go with Cantata and MPD. I have been an MPD user on my desktop system at home and my old laptop, and I like it.

Anyway, I had issues with getting mpd to play through pulseaudio, so having solved it I am documenting it here in case others come across the same problem.

• Modify the mpd configuration file: /etc/mpd.conf - uncomment and modify the audio output section for pulseaudio:
  

  Code:

  audio_output {         type            "pulse"         name            "Pulseaudio Output"         mixer_control   "Master"         server          "127.0.0.1" }

  
  
• Modify the pulseaudio configuration file at /etc/pulse/default.pa. Find the line relating to module-native-protocol-tcp and modify it:
  

  Code:

  ### Network access (may be configured with paprefs, so leave this commented ### here if you plan to use paprefs) #load-module module-esound-protocol-tcp load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1

  
  Note - I don't use paprefs
  
• Restart mpd as root (I'm using open-rc - you'll need to find the equivalent systemd command if that's how your system is configured):
  

  Code:

  /etc/init.d/mpd restart

  
  
• As user, restart pulseaudio:
  

  Code:

  pulseaudio -k

  
  

Now your mpd audio stream should be running through the pulseaudio setup (meaning in my case through my bluetooth speaker or headphones!). I hope that this information is useful for you!

[Ant P.]

I guess you're running pulseaudio as your normal user? If you're paranoid you may want to put "allow-module-loading = no" in daemon.conf, to prevent programs being able to create arbitrary files under your username.

I went the other route and set it up to use system-mode (the thing they try to scare you away from using) - it's a bit hard to get it working but it's fine when it does.

[paulj]

Yes - pulseaudio being run in the "standard" recommended way. Thanks for the tip - I'll look into adding the additional line in daemon.conf - hopefully it plays well with the bluetooth speaker being added or removed.

Are there examples of programs abusing this opportunity and creating files?

[Ant P.]

The two main things I see are module-ladspa-sink, which lets you run arbitrary LADSPA plugins in the pulse server, and module-pipe-{sink,source} which create pipe files at a user-supplied path. With it listening on a network address it's possible, albeit far-fetched, for something in the portage compilation sandbox to escape via that route.

But like I said, it's only necessary if you're really paranoid, and the manpage says it breaks hotplug so you probably don't want to do it with bluetooth (that's painful enough to deal with already!)

[paulj]

[Josef.95]

One year later …
Thanks for the tip -- it works fine :)

[paulj]

[Das_Sams]

I switched to paulj's solution, so I don't have to start it as root and as "dangerous" system-wide service.
Anyways, it sucks I have to remember starting it as user AND especially if mpd starts playing before I started it as user I have to kill it as root and then start it again to be able to watch videos. If mpd is playing at shutdown it will definitely
start it before there is any chance to do it as user.
There should be a better solution. It should be made safe to start PA as an init-script.