[Techtalk] MIdi, QjackCtl etc.

[Maria Pinjanainen]

ke, 2015-09-09 kello 01:00 +1000, Miriam English kirjoitti:
> Hi David,
> 
> Have you tried adding a synthesiser in the chain?
> 
> The keyboard is commonly used to send MIDI signals to control something. 
> Jack simply connects things together. Try using Jack to link the 
> keyboard to a synthesiser program like Qsynth or FluidSynth. Make sure 
> there are jack graphical connections between the keyboard and the 
> synthesiser. Jack has 3 different kinds of connections (at least on my 
> version): Audio, MIDI, and ALSA. It is a bit confusing because the MIDI 
> inputs and outputs can be in jack's ALSA panel or the MIDI panel. It can 
> be a bit frustrating at first to get the hang of the logic, but when you 
> do, it will kinda seem obvious in retrospect.
> 
> The synth should let you select different voices (piano, harpsichord, 
> violin, trumpet, etc). It may take a little while to find your way 
> around the synth program -- music programmers seem to be a different 
> breed from other programmers.
> 
> Let us know how you go.
> 
> Cheers,
> 
> 	- Miriam
> 
> 
> On 09/09/15 00:00, David Sumbler wrote:
> > On Sat, 2015-09-05 at 10:14 -0700, Terry wrote:
> >> On 05/09/2015 09:12, David Sumbler wrote:
> >>
> >> <snipped>
> >>
> >>> Cannot lock
> >>> down 82246176 byte memory area (Cannot allocate memory)
> >>
> >> <snipped>
> >>
> >> According to
> >> http://askubuntu.com/questions/166126/unable-to-start-jack-cannot-allocate-memory,
> >> the fix is to:
> >>
> >> 1.  usermod -a -G audio theusername
> >>
> >> 2.  Logout then login again as group membership is only updated on login.
> >
> > The error I mentioned was just one of the problems.  The link you gave
> > was useful, but having followed its suggestions I still have no sound on
> > either computer when using jackd.
> >
> >
> > On Sat, 2015-09-05 at 23:39 +0530, A. Mani wrote:
> > On Sat, Sep 5, 2015 at 9:42 PM, David Sumbler <david at aeolia.co.uk>
> > wrote:
> >>> I wonder if somebody can point me in the right direction for sorting
> > out
> >>> a midi system.  Search as I might, I can't seem to find any *basic*
> >>> information about how to set things up, or how things fit together.
> >>
> >>
> >>
> >> Join http://lists.linuxaudio.org/listinfo/linux-audio-dev , related
> >> mailing lists and have a look at their site.
> >
> > The users group and the documentation here will be very useful if and
> > when I can get the sound working on my computers.  But unfortunately it
> > does not cover difficulties in actually getting sound to work!
> >
> > Thanks to both of you for your suggestions.
> >
> > I can play a midi file using Timidity, and sound generally works OK on
> > both my computers.  The problem I have is that once I have Qtractor or
> > Muse running, with QjackCtl too, although everything appears to be
> > working I get no sound.  This is after experimenting endlessly with
> > different software connections.  It is the same on both computers,
> > although they undoubtedly have very different hardware from each other.
> >
> > David

I have played midi too. Have seen same kind of messages, and have a
feeling that jack-system not work well. when you play, you like to play
realtime, without any lag, and this jack does fine. Usually jack uses
Alsa, and connect midi and the synths to soundcards with it. But when
for example Pulseaudio is allready using audiodevices, it fails. So,
either skip the pulseaudio, like I did with that comp. or try to use the
pulseaudio with jack and play with a little lag.