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Rtc Timer.

Posted: Wed Apr 02, 2008 8:34 pm
by Alex
A LS unrelated challenge at the moment for me is Muse score. Werner has been going ahead leaps and bounds with this,and i have the hope that i can use LS for playback directly from Mscore, particularly as Werner has now implemented midi out (including ports. Woohoo.)

But i have a continuing problem with a message that reads:

alex@alex:~$ mscore
RtcTimer:: fatal error: open /dev/rtc failed: Device or resource busy
no midi timer available
RTC init failed

If anyone can help with this, i'd appreciate it.

I start mscore (while jack is running, using alsa seq for midi.) and get this message. This occurs each time i attempt to use the midi out from mscore (as opposed to the inbuilt soundfont synth) and i then have to go into mscore config and wipe the file, starting again with no midi out as default.
max user freq is 1024.


p.s. I am using the RT kernel.

Re: Rtc Timer.

Posted: Wed Apr 02, 2008 8:42 pm
by dahnielson
I have had problems with RTC myself in Rosegarden (don't remember the exact nature of it now) and have a related question. If I use JACK transport (which I do -- controlling Rosegarden from Ardour) does it matter what the sequencer timing source are? Or is it, as I hope and assume, overridden by JACK transport?

Re: Rtc Timer.

Posted: Thu Apr 03, 2008 3:08 pm
by Alex
Ok, an update.

I've got mscore working, using Linuxsampler for playback (Woohoo!). The new midi out feature Werner has built in mscore works well, and Linuxsampler plays back what's written faithfully, without any glitches or problems, even with heavy passages.

The RTC timer issue was, i'm almost ashamed to admit, easy to fix.
Alsa Seq uses RTC (at least on my system) as a timing source, so while Jackmp/Qjackctl/Alsa seq was running, the dev/rtc was busy. And as the rtc can only be used by one programme at a time, Mscore couldn't 'grab' it. So, i quite Jack/Alsa, started mscore first then started Jack/Alsa, and noted that even though Alsa seq no longer had exclusive use of RTC, it still started and ran with no problems, so i will assume here that Alsa seq uses my RTC by default, but when it can't, it then goes to another timing source, which i assume is system timer, and not RTC.

The best part is, Rosegarden doesn't need to use RTC either, if the bandwidth (user freq) is robust enough to run the system on it's own. (Mine is set to 1000khz, which is an increase from the UBStudio default of 250khz, a level somewhat insufficient for sustained audio use.)
So i can also run mscore (first in startup order), then jack/alsa, then RG, which is set to use system timer as the timing device. (Rosegarden 1.70-2SVN) I'm unlikely to do this, but if i wanted a midi file for recording, that wasn't notation (one that could be tweaked, without 'correct notation' as a requirement) it's entirely possible.

Once again, in all of this, Linuxsampler is at the centre, and being able to write score/playback using the same instrument samples, as those that will end up in a final recording, means a 'written' score will sound a lot closer to the intended end result than before.

My continued thanks go to the LS team for all their hard work and skills, and to the talented Werner Schweer and team at Mscore, who have been patience itself with my questions. and 'dumb user' challenges, and i'd also add my thanks to Chris Cannam and the fellas at the Ardour IRC, who helped me with the RTC challenge, and various aspects of Ardour.
Much appreciated to all of you.