mumble freezes all audio applications

[Björn Jacke]

after upgrading from 18.04 to 20.04 starting mumble freezes all audio applications.

The audio related log at startup:

JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
Cannot lock down 82280346 byte memory area (Cannot allocate memory)
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback

- running applications using sound freeze until mumble is stopped again

- starting for example a new mpv player (while a blocking mumble client is active) says "[ao/pulse] The stream is suspended. Bailing out."

The problem does not change if I disable all mumble plugins, it does also not change if I change audio input/output system to alsa/jack/pluseaudio or oss.

[Chris Knadle (chris-knadle)]

Björn Jacke:
> Public bug reported:
>
> after upgrading from 18.04 to 20.04 starting mumble freezes all audio
> applications.
>
> The audio related log at startup:
>
> JACK server starting in realtime mode with priority 10
> self-connect-mode is "Don't restrict self connect requests"
> Cannot lock down 82280346 byte memory area (Cannot allocate memory)
> audio_reservation_init
> Acquire audio card Audio0
> creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
> configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods
> ALSA: final selected sample format for capture: 32bit integer little-endian
> ALSA: use 2 periods for capture
> ALSA: final selected sample format for playback: 32bit integer little-endian
> ALSA: use 2 periods for playback
>
> - running applications using sound freeze until mumble is stopped again
>
> - starting for example a new mpv player (while a blocking mumble client
> is active) says "[ao/pulse] The stream is suspended. Bailing out."
>
> The problem does not change if I disable all mumble plugins, it does
> also not change if I change audio input/output system to
> alsa/jack/pluseaudio or oss.
>
> ** Affects: mumble (Ubuntu)
> Importance: Undecided
> Status: New

This issue also came up for Debian and is explained in bug #952742 ; by default
the Mumble client will start Jack if it is installed and will try to use it, but
there are no options in the GUI itself to control this.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=952742

This issue is fixed upstream with a one-line change not to start Jackd by default:

https://github.com/mumble-voip/mumble/pull/3990/commits/0780d93aab3eec9796e1cb8606c5f3c089d64eca

Mumble upstream is preparing a 1.3.1 bugfix release and recently uploaded an rc1
release candidate which I'm evaluating to see if it's releasable.

   -- Chris

--
Chris Knadle
<email address hidden>

[Björn Jacke (bjoern-j3e)]

Thank you for the pointer to the debian bug report. The workaround by disabling the start of Jack by editing the Mumble.ini works also here.

[Chris Knadle (chris-knadle)]

Björn Jacke:
> Thank you for the pointer to the debian bug report. The workaround by
> disabling the start of Jack by editing the Mumble.ini works also here.

Good, thanks for the verification that it's the same issue and that the same
solution works.

One thing to note: I cannot tell which package version of Mumble this bug
relates to; that's not shown anywhere in the Ubuntu bug report. Although I'm
the Debian developer for the package, I'm not an Ubuntu user -- so to figure it
out I had to go to https://packages.ubuntu.com, figure out that Ubuntu 20.04
meant the "eoan" release, and then look up the mumble package underneath eoan to
see that it's the same current released version from Debian unstable.

Now that I know that, I know that this could be fixed relatively easily via a
patched upload. Maybe I'll prepare that for now and hold off on trying to
release mumble 1.3.1 when it's ready rather than trying to release the release
candidate.

   -- Chris

--
Chris Knadle
<email address hidden>

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.