Ok, I tried incorporating some of the feedback on the recent upload of Oblivion I mentioned here.
@debra I tried shifting the balance more to the treble during problematic registrations (Intro, first theme, outro) but I kept the volume such that the bass did not disappear on my dinky builtin laptop speakers even when listening in mono. I find that the bass does a solid part in conveying the mood of the piece, so I did not want to leave that task to the treble alone.
@JerryPH I actually removed the reverb again: the one built into Shotcut was in my book detrimental to the sound quality. I'd need to experiment with a better quality external one. I also mapped about 20% of each side over to the other to avoid extreme headphone separation but still get stereo out of small base speaker systems like laptop/tablet and similar actually unsuited nonsense used by 90% of the populace. Shotcut has a "Stereo enhance" filter that sounds like it could cook up something more akin to actual stereo location when fed with separate left/right channels, but I found I didn't get convincing results out from that. Again, this has to wait until I have more convincing tools at my hand.
Now we get to "keyframes" in editing: keyframes are spots in the video where you set some parameter, and this parameter can change smoothly frame by frame until the video arrives at the next such keyframe with a different setting. I used this for adjusting the sound balance intermediately (see above), I also used it for the start and end of the video to introduce and remove the separate left/right hand views. I also used dozens of manually placed keyframes for determining where I get the left hand view from the front camera, since the left hand keeps moving with the bellows.
The idea was to use Shotcut's new Motion Tracking functionality to figure this out automatically. Sadly, it wouldn't have been able to do rotations, it would not have been combinable with the available filters/transforms to do the job I require, and it actually didn't even work in the first place (as a new feature, it probably did not agree with the setup I used for the video: maddeningly the ad-hoc preview tracked the bass side of the accordion pretty well, and the full analysis did not get anything right). So essentially I had to create one corresponding keyframe with rotation/offset for the bass side whenever I reversed bellows direction. That sounds worse than it was since my accordion has a long breath. You can see that the wall behind the bass side moves pretty smoothly between reversals: there was almost no keyframe necessary in the middle of a bellows movement. Whether that is a good or a bad sign for my bellows technique I don't know.
@JerryPH of course with greenscreening one could have avoided the bass side seasickness of the rolling wall. It's kind of droll, though. And I don't have a greenscreen.
Has anybody seen other accordion videos with a left hand closeup following the movement? I cannot imagine to be the first with that somewhat silly idea...
