I need to do an animation frame-by-frame changing a background-position of an element. I need to do this WITHOUT easing or linear animation, just changing the background-position. Is it possible to achieve with css3 animation?
Yes it is via the new step-function easing curves property.
Instead of "ease-in" etc. use "step-start" or "step-end" which will make the transition happen instantaneously either at the beginning or end of the time period specified in transition-duration.
You can also have multiple steps: "steps(N, start | end ])" which will have the transition happen in equally spaced steps.
AFAIK this is only supported in Chrome to date.