[LAU] Using keyframes in Shotcut for visually tracking accordion bass

I've recently made "prettified" accordion videos using closeups of both hands. That provides a pretty good distraction from the faces I pull when playing while still not nominally going for the "headless" look popular with some players likely having the same problem. <https://youtu.be/spAP7ODPCyg> Since the left hand moves all over the place with the bass part of the accordion, it requires keyframes to rein that movement in for the closeup. Shotcut recently acquired motion tracker, but so far I haven't got it to work, it doesn't track rotation, and there doesn't seem to be a way to apply results for creating a working closeup crop. So basically I went through the video until each bellows reversal and then straightened up the closeup, creating a keyframe. The greatest annoyance probably was that the rotation angle tended to be in the interval 350° to 20° and I had to manually convert every angle just below 360° into a negative angle in order to keep Shotcut from performing caprioles with the bass side of the accordion between keyframes. An option to constrain the rotation angle to some interval when using the visual controls for straightening things could be useful. I've worked with three cameras: one for the main video, one for each hand. The bass hand camera was tilted in a way to get as large an image as possible while keeping the bass side of the accordion somewhere in frame. On the audio side, this was sampled in Ardour with 96k on an Echo Audiofire card using jackd2 on Firewire (I had to ditch Pulsewire on Ubuntustudio because it got in the way). I employed the Guitarix wrapping of Zitareverb which does a much more convincing job than what Shotcut itself offers as "Reverb". Now if just my playing skills were up to what the tools do... Silk purses and all that. -- David Kastrup