Raspberry Pi Zero audio playback: vlcpulse audio output error: PulseAudio server connection failure: Connection refused

[Passiday]

I am checking if VLC Python bindings (https://wiki.videolan.org/Python_bindings) could serve for my project (media player on Raspberry Pi Zero).

By default, the RasPi Zero does not have audio output, and there are several standard ways to implement one. I chose to go the I2S audio path and set up the system accordingly.

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$ aplay --list-devices **** List of PLAYBACK Hardware Devices **** card 0: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0

I am running Raspbian Stretch Lite, so no GUI. Maybe some of the problems described below are related to this fact.

Testing the mp3 playback from commandline I get the sound, but there are several errors at start:

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$ cvlc song.mp3 VLC media player 3.0.3 Vetinari (revision 3.0.3-1-0-gc2bb759264) [00ed3650] vlcpulse audio output error: PulseAudio server connection failure: Connection refused [00f00f70] dbus interface error: Failed to connect to the D-Bus session daemon: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11 [00f00f70] main interface error: no suitable interface module [00e79420] main libvlc error: interface "dbus,none" initialization failed [00ef5ee8] main interface error: no suitable interface module [00e79420] main libvlc error: interface "globalhotkeys,none" initialization failed [00ef6198] dummy interface: using the dummy interface module...

When using the VLC Python bindings, only one of those errors remains, but twice:

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import vlc from time import sleep dir_path = os.path.dirname(os.path.realpath(__file__)) file_name = 'song.mp3' p = vlc.MediaPlayer(dir_path + '/' + file_name) p.play() sleep(5) p.stop()

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$ python test.py [0202c9c8] vlcpulse audio output error: PulseAudio server connection failure: Connection refused [0203d000] vlcpulse audio output error: PulseAudio server connection failure: Connection refused

[Passiday]

I am not sure should I be bothered, after all the audio playback is fine, and probably I could just ignore that error. But maybe there's some parameter, some configuration that I could do to get rid of this error? For example, if I run the cvlc with aout parameter, the 'Connection refused' error goes away:

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$ cvlc song.mp3 --aout alsa VLC media player 3.0.3 Vetinari (revision 3.0.3-1-0-gc2bb759264) [01138098] dbus interface error: Failed to connect to the D-Bus session daemon: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11 [01138098] main interface error: no suitable interface module [010d6420] main libvlc error: interface "dbus,none" initialization failed [0114b1c0] main interface error: no suitable interface module [010d6420] main libvlc error: interface "globalhotkeys,none" initialization failed [0114b228] dummy interface: using the dummy interface module...

[1MAXT3HKphYo]

If you want the error to go away you'll have to figure out how to configure pulseaudio on the pi zero. It's not necessary, however, since it seems you already have alsa working. Pulseaudio basically wraps alsa to add some more advanced mixing features and is most useful in a gui environment where you have multiple audio sources that need mixing. It would probably be pointless for your situation using stretch lite.