[Ardour-Users] xrun & automation

[David Adler]

On Sun, May 17, 2009 at 10:51 AM, . m u r m e r . <murmer at murmerings.com> wrote:
> David Adler wrote:
>>
>> http://lowlatency.linuxaudio.org/
>> http://www.google.com - be aware that some information
>> is outdatet
>>
>> and there is
>> http://ubuntustudio.org/
>> the audio-flavoured version of ubuntu. It seems to have
>> some performance issues at the moment though.
>
>
> thanks david, will check them out!
>
> best,
> patrick
>
hi patric,

2nd version, more verbose:
Not sure what you have done so far, a first step would be to
give realtime privileges to your user by appending something
like the following to /etc/limits.conf

@audio   -  rtprio     99
@audio   -  memlock    unlimited
@audio   -  nice      -19

and make sure your user is in the 'audio' group.

This little step often increases performance substantially.

Then play arount with the settings in qjackctl.
Have the realtime checkbox checked.
Start with a lagre frames/buffer size and decrease it until
xruns appear.
Try 2 or 3 periods/buffer, soundcards differ in what they
prefer.

If this works and you still need lower latencies, a patched
realtime-kernel (I guess ubuntustudio provides one for
jaunty) and probably some IRQ tweaking woul come next.

The list archives of ubuntustudio and the linux-audio-user
mailinglist contain much valuable information.

Linux-audio-distributions are somewhat pre-optimised,
there is a list here:
http://wiki.linuxaudio.org/apps/categories/linux_audio_bundles_distributions
I like 64studio -- but that's just my personal view.

best,
david