LinuxMusicians

Greetings all!

My main platform is Ubuntu DreamStudio 12.04 LTS. My DreamStudio desktop also contains an Oracle VM auxiliary, for Windows 7 Professional. The sole application on the latter is Sibelius. And a MIDI interface hooks digital piano to computer - connection recognized by both.

Nothing wrong with piano audio playback in DreamStudio, when opened as normal (ie no applications on desktop). However, with the VM on, and Sibelius on my screen, piano playback comes from Ubuntu as well as Windows/Sibelius, weirdly: Ubuntu's first and then, after half a second or so, Windows' (probably due to Windows GS Wavetable Synth's abominable latency).

Again, audio playback in Ubuntu alone works just fine. Evidently, there's no point in opening the VM with sound in Windows switched off, of course. And with Ubuntu sound manager on Mute, no audio playback at all - neither from Ubuntu, nor from Windows/VM - is forthcoming, obviously. So if I want to play Sibelius in the VM, I have a considerable problem.

Hence, it seems to me that Windows/VM doesn't dispose of an independent playback channel. For if it had one, the only thing to do (in order to get rid of this silly piano playback echo effect) would be muting Ubuntu's audio manager. In my reasoning anyway.

I'm perfectly well aware that this is not a Windows forum. But since Windows/VM audio playback appears to be completely fettered to Ubuntu's audio manager, I'm wondering as to whether in Ubuntu - theoretically - a separate playback audio path for Windows/VM (ie independent of Ubuntu's own) could be created.

An extra sound manager might be added, perhaps, linked to Windows/VM. Or some other tool allowing me to choose between either Ubuntu or Windows/VM audio output.

I'm hoping for helpful suggestions.

tnob

I'm no expert in virtual machines so if I'm wrong please somebody correct me, but I guess that the hosted environment (Windows, in your case) doesn't talk directly to the hardware, but relies on virtual hardware running within the host environment (Ubuntu, in your case). That is, the audio coming from windows doesn't go directly to your sound card, but to Ubuntu's audio stack, and THEN to the hardware, so it's entirely reasonable that if you mute your audio interface in Ubuntu you don't hear any sound from Windows as well.
You need to find what software is playing your piano sounds from Ubuntu and mute (or close) that one.

tnob wrote:Nothing wrong with piano audio playback in DreamStudio, when opened as normal (ie no applications on desktop).

Which application in Ubuntu is taking the MIDI input and producing the audio output? Can't you simply close that application?

I use VirtualBox on my Xubuntu 12.04. On VirtualBox you can choose per VM if what audio output you want: OSS, ALSA or Pulseaudio. I chose ALSA. So my VM is nothing than an ALSA client.

So when I have jackd running (and it's running all the time) then I have to redirect ALSA clients to jackd. I do this with the following ~/.asoundrc. Works fine:

pcm.!default {
type plug
slave.pcm "jack"
hint {
show on
description "Playback/recording through JACK"
}
}

pcm.jack {
type jack
playback_ports {
0 "system:playback_1"
1 "system:playback_2"
}
capture_ports {
0 system:capture_1
1 system:capture_2
}
hint {
show on
description "Playback/recording through JACK"
}
}