[Glastonbury] jackd

[tim hall]

Last Monday 03 January 2005 12:03, maurice was like:
> I just got round to looking seriously (well almost) at Rosegarden Midi
> Sequencer. Got it linked to jackd which was fortunately installed
> effortlessly by Mandrake. Rosegarden suggest a series of command-line
> arguments producing:
>
> /usr/bin/jackd -d alsa -d hw -r44100 -p 2048 -n 2

That should be a reasonable setting. If you use an external keyboard you might 
want to set -p lower (256, say) to get lower latency. I run with this 
slightly more complicated setting:
$ /usr/bin/jackstart -R -dalsa -dhw:0 -r44100 -p256 -n2 -s -S -i2 -o2
You need a kernel with realtime capabilities to use -R.

> It is clear that jackd has been invoked since the odd message appears
> saying it's being overloaded. However, it is also clear that there is
> absolute silence when playing a midi file and all system sounds are
> switched off and stay so until the system is re-booted. CD plays normally.
>
> Any suggestions please?

Yep. Install QJackCtl, it's a much nicer way (i.e. GUI) of launching Jackd and 
experimenting with settings. Jack probably disables Artsd when it launches, I 
think the two are mutually incompatible, so you need to relaunch it after 
you're done if you really want your box to bleep at you like that ;-).

As far as getting Rosegarden to produce sound, it doesn't by itself, you need 
to plug it into some kind of sound source. Install QSynth / fluidsynth and 
pop over to http://www.hammersound.net/ to grab some soundfonts - look in the 
'collections' section of their soundfont ibrary.

Then, in Rosegarden, go to Composition > Studio > Manage MIDI devices and make 
sure that Rosegarden can 'see' QSynth. Then you can assign voices to 
particular tracks by right-clicking and selecting a sound source from the 
drop-down menu.

It's possibly a little fiddly, but well worth it. I've had my head in 
Rosegarden all week, rather productively. Once it's set up it's very 
rewarding. :-) Let us know how you get on.

cheers

tim hall
http://glastonburymusic.org.uk