I have some sort of video stabilization enabled on my PC that I did not do myself. Doesn't have to do with browsers as the problem appears in multiple browsers and the Movie Player. Essentially the problem is two things:
The letterboxing seems to be consistently the same, making video get cut...
audiovisual
browser
computer issues
full screen
graphics
letterboxing
movie player
stabilization
tech support
tilt
video
video playback
video quality
widescreen
zoom