[LAU] Review: Monophonic pitch-to-MIDI converters for Linux

[Ralf Mardorf]

On Thu, 2013-05-09 at 17:15 +0200, hermann meyer wrote:
> Am 09.05.2013 16:45, schrieb Ralf Mardorf:
> > Hi :)
> >
> > right now I'm testing Rakarrack. I already played Yoshimi by
> > guitar-to-MIDI, using Rakarrack's converter and it seems to be worth to
> > continue testing :).
> >
> > Are there other pitch-to-MIDI converters available for Linux?
> > Are there any secret tricks, to improve the guitar-to-MIDI conversion?
> >
> > $ pacman -Q guitarix-git
> > guitarix-git 20130507.2031-1
> >
> > Regards,
> > Ralf
> >
> I've just (some hours ago) pushed a update to gxtuner.lv2 which is meant 
> to clean the midi output a bit. Its a LV2 plug Monophonic pitch-to-MIDI 
> converter. In gxtuner.lv2 the 'secret' is to set the threshold for the 
> tuner and the note-on level to the 'right' level according to your input 
> device.
> But as least this one is far, far away from being perfect, if it is 
> worth a try you must decide yourself.

I tested guitar to MIDI using Rakarrack and for some of my needs it does
work very good, resp. it would do, if I could get a lower latency, but I
can't get lower than 256 frames/period at 48 KHz, IOW 10.7 ms. This
latency is ok to play virtual synth by a keyboard, but it's to much to
"use" the "drawbacks" of the pitch to MIDI conversion, without causing a
bad musical timing. If the latency would be shorter, it would be
possible to control the drawbacks and to use them, while still playing
in time. It's less useful to play guitar and to convert after the guitar
is recorded, since then we can't control what the converter should do,
this only is possible, if we can listen in real-time, while playing, so
that we can directly interact with the converter. I got very good
results, but with a bad timing, regarding to the latency.

If latency wouldn't be an issue, I also would test gxtuner.lv2. Every
guitarist interested in guitar to MIDI, who has no issues with his audio
Linux, should test at least Rakarrack. I suspect that a latency half of
the one I get, IOW <= 5.33 ms, will be good enough for interaction. I've
got no chance to get that low with my RME card :(. I already get tons of
xruns when using 256 frames/period at 48 KHz, IOW 10.7 ms and there's
nothing I can tune on my machine, it's already tuned.

Good software! but the old Linux issue, terrible bad hardware support! I
don't think using another mobo with my card would improve it, since the
driver for my RME card is a PITA and I guess it's not maintained for my
card.


Regards,
Ralf