Re: [LAU] midi backend not working in qjackctl?

From: Ralf Mardorf <ralf.mardorf@email-addr-hidden-dsl.net>
Date: Wed Mar 14 2012 - 18:59:52 EET

On Wed, 2012-03-14 at 12:40 -0400, Paul Davis wrote:
> On Wed, Mar 14, 2012 at 12:32 PM, Ralf Mardorf
> <ralf.mardorf@email-addr-hidden-dsl.net> wrote:
>
> > IIRC it was in April 2011 Jack2 1.9.8 from svn. Here hw jitter is close
> > to zero.
>
> then your definition of jitter is very different from mine.

Perhaps just good luck. For my old Envy24 sound card MIDI jitter
correlated to the latency. The more latency, the more positive and
negative drift I got for audio recorded MIDI events from hw synth.
I never made MIDI recordings since I own a RME card.

FWIW ALSA MIDI sequencer timer was hrtimer and tickless was enabled by
the kernel. It's also said that tickless should be bad and I experienced
it vice versa.

For soft synth I never noticed serious issues, at least not for my
production Linux, even if I used 'seq' instead of a2jmidid.

FWIW mobo ASUS M2A-VM HDMI, without the HDMI thingy , but instead a
GeForce 7200 GS. AMD Athlon dual-core BE-2350. Sound card TerraTec EWX
24/96, PCI. I won't refer to ascertained measurement results, they might
be wrong, but others and I heard "improper timing" before and steady
timing when using -Xalsarawmidi.

- Ralf

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-user
Received on Wed Mar 14 20:15:04 2012

This archive was generated by hypermail 2.1.8 : Wed Mar 14 2012 - 20:15:05 EET