[linux-audio-user] Status of JACK midi sync?

[Lars Luthman]

On Wed, 2006-10-11 at 20:21 -0400, Ivica Ico Bukvic wrote:
> > JACK MIDI is in JACK 0.102.20.
> 
> Cool! Now the next logical set of questions is:
> 
> 1) How stable/reliable is it?

Pretty reliable. I haven't made it crash since 0.102.5.

> 2) Are there any apps that support it?

The only ones I know of that support it officially in released versions
(please reply if you know of more) are Ghostess (Sean Bolton's DSSI
host) and Dino (my sequencer). There is a patch for Zyn and the SVN
versions of Ingen (Om) and Specimen supports it. Connecting JACK MIDI
ports works fine in Patchage and QJackCtl, although they appear in the
"Audio" tab in QJackCtl. Dave Robillard also worked on MIDI in Ardour
during the summer, so I suppose there is some kind of support there too.

> 3) Does such support require a major rewrite?

Depends on the software. If you are doing a lot of MIDI processing in
another thread it may take some hacking, but if you just read ALSA MIDI
events in another thread and pass them to the JACK thread using a
ringbuffer or something similar it's easy - just get rid of the extra
thread and the ringbuffer. I wrote the patches for Specimen and
ZynAddSubFX, and for Specimen (which pretty much does that) it was
really easy, while it was a bit trickier for Zyn (which does a lot of
MIDI processing outside the audio thread).

-- 
Lars Luthman - please encrypt any email sent to me if possible
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