[alsa-devel] [FFADO-devel] M-audio Audiophile Firewire

[Jonathan Woithe]

On Sun, Oct 23, 2016 at 08:22:32PM +0200, Peti Pap wrote:
> I installed now an Ubuntu 16.10 (because this distro can handle ffado 2.3
> well), and now almost work the playback (but sometimes a bit noisy, and I
> dont know the reason).
> When I start the FFADO Mixer from terminal, I get the following messages:
> 
> Cannot create RT messagebuffer thread: Operation not permitted (1)
> Retrying messagebuffer thread without RT scheduling
> Messagebuffer not realtime; consider enabling RT scheduling for user

This indicates that your user does not have access to the realtime
scheduling features on the system.  While this should not affect the
operation of ffado-mixer (and its related ffado-dbus-server), it will cause
problems if you choose to use the FFADO audio streaming system via jackd's
"firewire" backend.  From the above message I'm not sure if you're doing
this though: the "noisy" playback might still be relating to your use of the
ALSA streaming driver.

On most distributions it is sufficient to add your user to the "audio".

Not having access to the realtime scheduling shouldn't cause ffado-mixer any
problem.  However, just to be sure it's probably worth adding your user to
the audio group to see if that improves the ffado-mixer behaviour.

> -----------------------------------------------
> FFADO Control DBUS service
> Part of the FFADO project -- www.ffado.org
> Version: 2.3.0-
> (C) 2008, Pieter Palmers
> This program comes with ABSOLUTELY NO WARRANTY.
> -----------------------------------------------
> 
> 1477244892717343:  (ffado-dbus-server.cpp)[ 270] main:  Discovering
> devices...
> 03966254548:  (ffado-dbus-server.cpp)[ 329] main: DBUS service running
> 03966254588:  (ffado-dbus-server.cpp)[ 330] main: press ctrl-c to stop it &
> exit
> 03966254597: Debug (ffado-dbus-server.cpp)[ 333] main: dispatching...
> 03970152237: Error (avc_avdevice.cpp)[ 300] supportsSamplingFrequency:
> sample rate not supported by input plug

I'm not sure what would cause this.  Was the device actively streaming audio
at the time you started ffado-dbus-server?  That still shouldn't cause any
issues, but obviously something is amiss.

> (And if I close the mixer GUI, I cant re-open again without killing the
> ffado-dbus-server)

That's strange.  Something seems to be getting hung up somewhere.

Peti: to keep the original thread in alsa-devel on topic, you may like to
subscribe to ffado-devel and start a fresh thread there about the
above ffado-mixer / ffado-dbus-server issues you are seeing.

Regards
  jonathan