Re: [Denemo-devel] Newbie getting MIDI K/B to work with ALSA and qjackctl - update - some progress

[Philip Rhoades]

Edgar,


On 2014-01-19 20:04, Edgar Aichinger wrote:
> Am Sonntag, 19. Januar 2014, 14:08:26 schrieb Philip Rhoades:
>
> > This is what I have in Edit-Preferences-Audio/MIDI - seemingly no 
> > matter
> > what I do:
> >
> >    Audio Backend
> >      PortAudio
> >      JACK
> >      none
> >
> >    Output Device
> >      Lots of ALSA devices
> >
> > the third panel has:
> >
> >    MIDI Backend
> >      ALSA
> >      JACK
> >      none
> >
> > - can you tell me what you see in your setup?
>
> The same. My build supports portaudio, but not portmidi, because of
> the bug i referred to in my previous post. I tried to come up with a
> quick solution yesterday, but failed, and won't have much time next
> week to look at it again, sorry.
>
> For me choosing either ALSA or JACK as MIDI Backend just works. For
> JACK the jackd server has to be running of course...
>
> Choosing the backend and pressing OK immediately creates the
> respective denemo port, so it become visible in e.g. qjackctl in the
> ALSA resp. MIDI tab (right panel), and I can connect my keyboard (left
> panel) to it.
>
> To use JACK MIDI properly you have to start the a2jmidid daemon or use
> the -X seq commandline option (MIDI driver config option in qjackctl)
> to jackd, both methods will forward ALSA MIDI ports to the JACK MIDI
> system. JACK MIDI itself doesn't create hardware ports, so you need
> that to see your MIDI keyboard in qjackctl's MIDI tab. a2jmidid is
> preferred over -X seq because it supplies better MIDI timing.


OK, I have made some progress but a thorough analysis would require lots 
of reboots of my server and I don't have time to do that at the moment - 
sticking to ALSA for the time being:

- if I boot with the MIDI K/B plugged in - user "phil" can't get 
ANYTHING going at all - no normal sound with mplayer, no MIDI 
connections; root can get sound reliably and MIDI connections about half 
the time; I think the order of the sound cards is being changed and also 
there is a permission problem somewhere - I tried chmodding everything 
in /dev/snd to 666 but it didn't help

- if I boot WITHOUT the MIDI K/B plugged in and plug it in after booting 
- user phil and root can actually have normal sound plus MIDI connection 
maybe about half of the time? - sometimes the existing Preferences setup 
"just works" - like you said, but sometimes I have to reselect an item 
and save it or select something else, save it and then change back to 
what is listed above - sometimes I can't get it to work until another 
reboot

- with limited testing, a cold boot seems to give better results than a 
warm boot?

- sometimes, making some change or other will cause the loss of sound 
and I will have to reboot just to get a working machine

At least now I know it can be made to work eventually, even if the 
situation seems to be a bit hit and miss . .

Thanks to all!

Regards,

Phil.
--
Philip Rhoades

GPO Box 3411
Sydney NSW      2001
Australia
E-mail:  address@hidden