Re: [LAU] MIDI keyboard not recognized

Ok Pedro thanks a lot for the insight !
Very interesting to know how things work from the inside :)

I'll try the various commands tonight and give a report here as soon as
it's done

Thanks again and cheers

jy

2012/9/11 Pedro Lopez-Cabanillas <pedro.lopez.cabanillas@email-addr-hidden>

> Hi,
>
> On Tuesday 11 September 2012, jy wrote:
> > still no appearance of the midi keyboard.
> >
> > I also tried with all proposed audio cards in qjackctl setup but still no
> > midi keyboard (even though the keyboard is correctly listed as an
> > interface in the interface combo box)
> >
> > I'm starting to feel like this is hopeless (i'm gonna shed a tear) :-)
> >
> > just to know, how does jack know about the midi devices present. does it
> > rely on ALSA ?
>
> Yes. Jack depends on ALSA drivers to work with hardware MIDI devices, just
> like it depends on ALSA drivers to work with hardware audio devices,
> except
> for FireWire devices where jack depends on ffado/freebob. Jack does not
> have
> its own hardware drivers.
>
> > Would a message found in dmesg like :
> > [ 782.208027] usb 7-1: new full-speed USB device number 8 using uhci_hcd
> > when plugging in the keyboard be of any interest in my case ?
>
> Yes, it is a good sign. Answering your previous question:
>
> > Does anyone know from where qjackctl gets its MIDI device list ?
>
> The ALSA tab is filled from the ALSA Sequencer list of ports, which can be
> hardware devices or software applications.
>
> The MIDI tab list comes from one of those bridges that provide MIDI support
> to jack.
>
> If you should solve the problem at the ALSA level, I guess that you will be
> able to solve the problem with jack as well at the same time.
>
> ALSA provides a number of kernel modules. You can list them with this
> command:
>
> $ lsmod | grep ^snd
>
> My guess is that some modules are not automatically loaded in your system.
>
> Summing up your previous diagnostics, the ALSA hardware driver (snd-usb-
> audio) recognizes your device properly:
>
> $ cat /proc/asound/cards
> 1 [v2 ]: USB-Audio - USB Oxygen 8 v2
> M-Audio USB Oxygen 8 v2 at usb-0000:00:1d.1-1, full
>
> And the ALSA raw MIDI interface (snd-rawmidi) is working properly as well:
>
> $ amidi -l
> Dir Device Name
> IO hw:1,0,0 USB Oxygen 8 v2 MIDI 1
>
> In your previous messages it is not clear if the ALSA Sequencer interface
> is
> working or not for you. To verify, there are several tests that you can
> try.
>
> $ cat /proc/asound/seq/drivers
> snd-seq-midi,loaded,2
>
> $ cat /proc/asound/seq/clients
> Client info
> cur clients : 4
> peak clients : 5
> max clients : 192
>
> Client 0 : "System" [Kernel]
> Port 0 : "Timer" (Rwe-)
> Port 1 : "Announce" (R-e-)
> Client 14 : "Midi Through" [Kernel]
> Port 0 : "Midi Through Port-0" (RWe-)
>
> Another way is the ALSA sequencer player (from the ALSA tools collection):
>
> $ aplaymidi -l
> Port Client name Port name
> 14:0 Midi Through Midi Through Port-0
> 20:0 MidiSport 2x2 MidiSport 2x2 MIDI 1
> [...]
>
> Or the ALSA Sequencer event monitor/receiver:
>
> $ aseqdump -l
>
> If some or all the above tests failed, my guess is that the ALSA Sequencer
> modules aren't loaded. In that case, you may try this command:
>
> $ sudo modprobe snd-seq-midi
>
> Regards,
> Pedro
>

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Received on Tue Sep 11 12:15:03 2012