[MU4 Issue] Playback high pitched when using Surround WASAPI Audio Output (Buffering issue)

[heisluft]

Issue type

General playback bug

Bug description

MuseScore 4 does not handle Surround WASAPI output correctly, the samples intended only for two channels gets split up into all channels (can be seen in my mixer software, see atached video), so when the remaining samples (in my case only 1/4 of all samples (7.1 configuration)) get played pack, it sounds hig pitched and sped up. I discovered this while testing builds for #15235 (Although the issue should persist scince MultiChannel Output was first introduced in #15698.

Steps to reproduce

1. start a mu4 instance built with code from #15698.
2. select a multi channel WASAPI output in settings
3. Playback any note or song
4. Sounds high-pitched and sped up. In mixing software of the audio device it can be seen that all channels of it receive input, not just the first two.

Screenshots/Screen recordings

https://user-images.githubusercontent.com/30872344/223803798-83b0316b-dd1f-4826-b072-44ac51783762.mp4

MuseScore Version

= 4.0.1

Regression

No.

Operating system

Windows 10

Additional context

No response