MuseScore notes on Fedora Core 12

Random notes playing with MuseScore 0.9.6 (pun not intended):

Installation (after grabbing the RPM file from the web):

# yum install --nogpgcheck MuseScore-0.9.6-1.fc12.x86_64.rpm

Which installs the file with no signature. Somewhat dangerous in theory, as the RPM could in theory contain malicious code (as if a signature helps in this case).

The command line for kicking it off is

$ mscore &

Crashes

MuseScore may enter an infinite memory hogging loop, ending up with a system global OOM and a lot of disk activity. To keep this mishap’s impact small, allow it no more than 2 GB of virtual memory, for example. It will never need nearly as much as that, and once it gets into this “all memory is mine” loop, it gets a kick in the bottom, and that’s it. So before calling mscore, go

$ ulimit -v 2048000

and possibly check it with

$ ulimit -a

Note that this limits any program running from the same shell.

Editing notes (to self, that is)

• Selection: In no-note-writing mode, press Shift and mark an area. It’s also possible to mark a note, and shift-click the last note to select (including from the beginning to end).
• Beaming: That’s the name of connecting eighth and sixteenth notes with those lines. Look for “beam properties” in the palette to get separate notes, as commonly written in notes for singing.
• In the Display menu, select Play, Mixer and Synthesizer panels, to control sound and played tempo. Note that the mixer panel remains in place when closing and opening files, but it becomes dysfunctional at best after that. Just reopen the panel after reloading or such.

Hearing something

To get some audio playing, given errors like this on startup

Alsa_driver: the interface doesn't support mmap-based access.
init ALSA audio driver failed
init ALSA driver failed
init audio driver failed
sequencer init failed

go to Edit > Preferences, pick I/O, choose ALSA Audio only, and set the Device from “default” to “hw:0″.

But ehm, there’s a problem: Musescore requests exclusive access to the sound device, so if anything else happens to be producing sound when Musescore starts, it will fail to initialize its sound interface (and therefore not play anything during that session). And if it manages to grab the soundcard, all other programs attempting to play sound get stuck. This is true even when using a TCP socket to connect to the PulseAudio server.

Portaudio doesn’t make things better. To begin with, it’s a bit confusing, as the API and device entries are empty. But just select it and click “OK” and these become populated after a restart of the program. Not graceful, but it works. Anyhow, picking the ALSA API and the hw:0,0 device (which is my sound card) gets the same result as with ALSA directly, minus I can’t control the volume with the Pulseaudio controls. But the card is still grabbed exclusively, messing up other programs.

Portaudio with OSS didn’t work either, despite running mscore with padsp. No devices appeared in the list.

Loading the OSS compatible driver (modprobe snd-pcm-oss) created a /dev/dsp file indeed, but again, the sound card was exclusively taken.

My ugly solution was to find a couple of USB speakers and plug them in. And use hw:2,0 as the ALSA target in Musescore.

The elegant solution would be to create a bogus hardware card in Pulseaudio, that routes all sound to hw:0,0. I’m sure it’s possible. I’m also sure that I’ve wasted enough time on this nonsense.