Greg's House of Treats

Ran across CEDET while looking for the matlab editor settings. Looks interesting.

http://cedet.sourceforge.net/

Ran across this on freshmeat, might be worth a look.

http://www.ics.forth.gr/~lourakis/levmar/

The lecture notes also worth a look.

http://www.imm.dtu.dk/pubdb/views/edoc_download.php/3215/pdf/imm3215.pdf

Rosegarden fails with message "Failed to connect to JACK audio server". So, need to start jack. Jack fails with message "JACK is running in realtime mode, but you are not allowed to use realtime scheduling." I guess JACK ignores the fact that I unchecked "Realtime" option in the setup window. Oh well. Guess it really wants realtime (lame). Probably it's just a bug in the Qt gui rather than a Jack bug, because I see the -L flag is not actually sent on the jackd command line.

Anyway, I run sudo dpkg-reconfigure jackd, and tell it to use realtime priorities. This doesn't seem do anything at all.

Next, I do what Jack suggests, and edit /etc/security/limits.conf

@audio          -       rtprio          100<br />@audio          -       nice            -10<br />

This didn't do it for me though. Maybe I have to reboot? Yep, that solves this problem. Probably I could have restarted pam, but I had no patience for sidetrack on this issue.

Also, I get a warning from Jack that I need to set the maximum locked memory. How much is a good value? I just try the recommended value.

@audio          -       memlock 240144<br />

Next, I get an error message:

ALSA: final selected sample format for capture: 16bit little-endian<br />ALSA: cannot set period size to 1024 frames for capture<br />ALSA: cannot configure capture channel<br />cannot load driver module alsa<br />

Turns out that my card doesn't like 1024 frames per capture. Change this using qjackctl. 512 is OK? Well OK!

ALSA: final selected sample format for capture: 16bit little-endian<br />ALSA: use 2 periods for capture<br />ALSA: cannot set hardware parameters for capture<br />ALSA: cannot configure capture channel<br />

Hm, not so clear what this means. Google is utterly without comment. However, I found if I change the input channels from (default) to 2, this error message is cleared.

All is not well however. Starting Jack from qjackctl causes the program to freeze, and I have to kill it. Starting it from command line and starting rosegarden yields the following:

gsharp@stonesmith:~$ /usr/bin/jackd -dalsa -dhw:0 -r44100 -p512 -n2 -S -i2<br />no message buffer overruns<br />jackd 0.116.2<br />Copyright 2001-2005 Paul Davis and others.<br />jackd comes with ABSOLUTELY NO WARRANTY<br />This is free software, and you are welcome to redistribute it<br />under certain conditions; see the file COPYING for details<br />JACK compiled with System V SHM support.<br />loading driver ..<br />apparent rate = 44100<br />creating alsa driver ... hw:0|hw:0|512|2|44100|2|0|nomon|swmeter|-|16bit<br />control device hw:0<br />configuring for 44100Hz, period = 512 frames (11.6 ms), buffer = 2 periods<br />ALSA: final selected sample format for capture: 16bit little-endian<br />ALSA: use 2 periods for capture<br />ALSA: final selected sample format for playback: 16bit little-endian<br />ALSA: use 2 periods for playback<br />jackd watchdog: timeout - killing jackd<br />

In addition to jack dying, rosegarden complains about the lack of an RT timer, suggesting sudo modprobe snd-rtctimer.