This disclosure describes techniques for encoding digital video data using interpolation filters and offsets. An encoder may be configured to select interpolation filters for sub-pixel precision motion estimation based on historical interpolation results obtained for previously encoded video units, such as frames or slices. The encoder also may be configured to compute and assign offsets to the sub-pixel positions after interpolation based on differences between a reference unit and the unit to be coded. The computation and assignment of offsets may be performed before motion estimation. Motion estimation may be refined so that the motion search considers sub-pixel positions to which offsets have been previously added and evaluates sub-pixel positions that have a non-zero offset. In some cases, interpolation filter selection, offset computation, and/or refined motion estimation for a given unit may be performed in a single encoding pass.