Not an FDR input, but would be monitored by an anti-lock system: at the exact point of liftoff the tires will instantaneously begin to slow in rotation at a linear rate. You will have a separate lift-off for each independent axle. If there is a bounce the speed will suddenly increase to flight speed. Even if the data rate for the rotation monitoring isn't high, one can interpolate both the on-ground speed and the airborne speed and see where they intersect.
WOW may indicate before the last contact with the ground has occurred and there won't be a way to determine exactly when except that it happened between two recorded times. WOW, OTOH, is almost certainly recorded in any aircraft that depends on WOW for automation.