MIDI Output doesn't work

• Sep 25, 2009 - 22:20
Type
Functional
Severity
S4 - Minor
Status
closed
Project
MuseScore

Tested with Revision 2101:2102M and the stable MuseScore 0.9.5. MIDI Output doesn't work for me on my Kubuntu 9.04 machine. The console prints:

silentcry@silentcry:~/svn/mscore/trunk/build$ mscore
RtcTimer:: fatal error: open /dev/rtc failed: Permission denied
MidiSeq:start(): no midi timer available
Cannot start I/O
sequencer init failed

Steps to reproduce:

1. Mark "MIDI Output" under "Edit | Preferences | I/O"
Note that although enabling "auto-connect" the connection is not made. I did it manually with kaconnect.
2. Restart MuseScore
3. Press play. No output, and the cursor won't move aswell.

Comments

• Sep 26, 2009 - 10:25

On a default Ubuntu installation /dev/rtc0 is owned by root. When I set its ownership to my user account I get this message:

silentcry@silentcry:~/svn/mscore/trunk$ mscore
RtcTimer::setTimerFreq(): cannot set ticks 1024 on /dev/rtc: Permission denied precise timer not available
MidiSeq:start(): no midi timer available
Cannot start I/O
sequencer init failed

And if I start mscore as root, everything works fine. Although it seems to be a bad idea to start mscore with root permissions...

Reply

• Sep 28, 2009 - 17:18
Status (old) active ⇒ by design

You need the permission to set the timer frequency to 1000Hz or more. For this append the line

dev.rtc.max-user-freq=1024

to the file /etc/sysctl.conf.

Reply

• Oct 1, 2009 - 19:50
Status (old) by design ⇒ active

Thanks for your reply, but somehow that command doesn't change anything for me... Could it be possible that the "ubuntu-way" is different? Because /dev/rtc is a symlink to /dev/rtc0. According to chown both have the necessary permissions set... This is really getting strange...

Reply

• Oct 7, 2009 - 21:51
Status (old) active ⇒ fixed

In the last revisions the midi output has changed. JACK midi is supported which eliminates the need for /dev/rtc.

Reply