Re: Routing MIDI controllers with sndio on Linux.

On Sat, Apr 08, 2023 at 10:44:41AM +0200, Brian Durant wrote:
> On 4/5/23 5:20 PM, Alexandre Ratchov wrote:
> > On Wed, Apr 05, 2023 at 04:54:53PM +0200, Brian Durant wrote:
> > > How are MIDI controllers routed with sndio on Linux? On OpenBSD, MIDI ports
> > > are named "midi/0", "midi/1", and they correspond to the "midi0 at ..."
> > > lines of dmesg. I am currently using sndio on Void Linux (mainly for support
> > > of my MIDI controllers), and the MIDI controllers are typically listed as:
> > > 
> > > 
> > > [ 75.825351] usb 1-12: Product: A-PRO
> > > 
> > > [ 75.825355] usb 1-12: Manufacturer: Roland
> > > 
> > > [ 142.346575] usb 1-12: USB disconnect, device number 7
> > > 
> > > [ 215.239705] usb 1-12: new full-speed USB device number 8 using xhci_hcd
> > > 
> > > [ 215.367162] usb 1-12: New USB device found, idVendor=09e8, idProduct=0076,
> > > bcdDevice= 1.00
> > > 
> > > Unfortunately, I am unable to route any of my controllers to LMMS (with
> > > sndio set as the MIDI interface in the LMMS preferences), such as to the SF2
> > > plugin. I am able to set the MIDI input properly in LMMS (in the plugin),
> > > but I am apparently not getting a MIDI signal from the keyboard. This is
> > > where that I suspect that there could be a routing issue.
> > > 
> > > Sooo, assuming that everything else is equal to sndio on OpenBSD, I need to
> > > run a similar command, with the equivalent of "midi/0" in Linux:
> > > 
> > > $ midicat -d -q midi/0 -q midithru/0
> > > 
> > > Of course with the correct variable for the relevant MIDI device.
> > > 
> > 
> > It's supposed to be the same than on OpenBSD, for better and for worse.
> > 
> > Could you post the output of 'amidi -l'?
> 
> Hmm. My reply didn't seem to get through. Here it is again:
> 
> $ amidi -l
> Dir Device    Name
> IO  hw:0,0,0  UMC404HD 192k UMC404HD 192k MID
> IO  hw:3,0,0  A-PRO MIDI
> IO  hw:3,0,1  A-PRO 1
> I   hw:3,0,2  A-PRO 2
> 

Oh, my bad, on linux, devices have the ",X,Y" suffix, so you need
these sndiod options for the same openbsd commands to work there:

sndiod -q rmidi/0 -q rmidi/3,0,0 -q rmidi/3,0,1 -q rmidi/3,0,2 <your-other-options>

this will map what programs refer to as "midi/0", "midi/1", ... to
above.