You might want to look at YouTube's delivery specs and match them.
I have a slow connection, and nothing plays in real time. This is horizontal motion, and you could be seeing a phenomenon called Judder, a combination of motion and frame rate. There's not much you can do about it except change the speed of the motion or the frame rate; higher is smoother.
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Yea, it's judder.
You need to slow it down, or at least vary the speed, maybe add in a little rotation on the Z axis (like the camera is rolling back and forth a bit), and you should probably add motion blur.