[suggestion] i come to a forum thread requesting a centering of a cropped video...
here the thread: https://forum.kde.org/viewtopic.php?f=270&t=176692 and i canfirm (and already know) that there is not a way to center the cropped video, it's possibile to add allignment functions (only x and y) taking care of cropped sections and scale?
Right now there is no other ways to crop a clip or image and a lot of time this cropped piece need to be centered on screen... strange that there are not yet these centering functions.