midi playback issue (chorus/reverb) still happens in Musescore 2.0 beta

• Oct 2, 2014 - 15:56
S4 - Minor
needs info

Sometimes the midi playback breaks. After a couple of measures it sounds like its under water and it starts to slow down and becomes unusable. Once this issue starts it continues even after you stop and start the program -- I think the problem is in a driver somewhere. This is a known bug. The fix is to bring up the Musescore mixer and simply adjust the reverb/chorus. This completely fixes everything.

I have several programs for midi playback, all configured the exact same way. Musescore is the only one where this problem happens.

I'm guessing that the program needs to send a midi chorus/reverb message at the start of every playback regardless of whether the mixer has them set to 0 or not.


Actually, it's *not* a known bug regarding 2.0. There was a bug like that in 1.2, but it was fixed long ago for 1.3, and wasnnot part of the 2.0 Beta or any recent Nightly build. So if you are seeing a problem with a specific score, specific soundfont, specific effects settings, etc - please post the score, name the soundfont, describe the effects settings, and give precise steps to reproduce.

Status (old) active needs info

Altering reverb or chorus controls is unlikely to make any difference in 2.0 beta as the controls no longer send data to FluidSynth. For this reason, then, it is unlikely to be a driver problem.

My guess is that it is a memory/CPU issue with your computer, but it is only a guess without details of a) your OS and b) your hardware setup.

Incidentally, the fix in 1.2 wasn't to move mixer controls, but to move the reverb return control in the Synthesiser dialogue.

This is no longer present in 2.0 beta.

The only time moving chorus and reverb mixer controls has any effect in 2.0 beta is if you are using Jack MIDI output to drive an external synth.

I am not using jack MIDI output. Once I muck with the mixer chorus/reverb settings the bug is fixed until I reboot (Vista, 4Gb memory). I also use Sibelius without any problems. Once the problem starts it doesn't matter what score you play, it happens every time after only a few measures. The longer you let it play the more 'underwater' it sounds and it grinds to a halt. Move the chorus/reverb while its messed up and playing and it's fixed immediately. So something happens when you move the chorus/reverb buttons and it is a very good thing. Other settings that may matter to you guys: PortAudio checked, Jack not checked, API=MME, Device=Speakers (RealTek), Soundfont= FluidR3Mono_GM.sf3.

Hmm I suspect a memory leak?

That would explain why it gets worse as playback continues.

FWIW I have experienced this in 1.3 and an early nightly build of 2.0 in the days when I was running XP on a Sony Vaio netbook. I had a set of USB speakers which were particularly prone to the problem, but it occasionally happened with the Realtek sound system.

Since I upgraded to a desktop with an i3 processor and 8GB RAM the problem has ceased.

Does the problem reappear every time you reboot the machine?

Also are you using an Intel or an AMD processor?

I just rebooted to verify. Sure enough the problem came back the first song I loaded. However, the reverb dial on the mixer is not the fix -- it's the chorus. As soon as it moves off of 0 the problem is fixed. You can set chorus back to 0 after and it still works. It is that first movement that does the magic. Also, if I shut down the program and restart, the problem came back and chorus fixed it a second time. You asked about processor: intel core 2 duo.

What exactly happens when you move the chorus dial off of 0 when a song is already playing?

One final question are you using EAX effects?

In theory moving the chorus control should do nothing apart from update the Mixer graphics unless you are using Jack MIDI output, in which case it transmits chorus controller data through the MIDI out.