1. An apparatus for motion estimation in video encoding, comprising: a binary pyramid construction module for transforming video images into first, second and third binary layers; a static-state checking module determining if said apparatus is in a static mode or a normal mode based on repeat occurrence of final motion vectors; a first level search module receiving said first binary layer and performing parallel XOR block matching with a ±3 pixel refinement window in a first level and generating a first level motion vector for said normal mode; a second level search module receiving said second binary layer and using six motion vector candidates to determine a second level motion vector for said normal mode; a third level search module receiving said second level motion vector and performing parallel XOR block matching with a ±2 pixel refinement window in a third level and generating a final motion vector for said normal mode; a fine tuning module performing parallel XOR block matching with a ±1 pixel refinement window and generating a final motion vector for said static mode; and a state update module registering and updating said repeat occurrence of final motion vectors.