Patent ID: 7912128

Claim:
A motion vector estimation system for estimating an output motion vector of a first macroblock of a first frame, the motion vector estimation system comprising: a motion vector prediction circuit for generating a predicted horizontal motion vector and a predicted vertical motion vector; a search window offset detecting circuit for generating a shifted horizontal motion vector based on the predicted horizontal motion vector and a predetermined threshold, the search window offset detecting circuit further shifting a search window corresponding to the first macroblock of the first frame by the shifted horizontal motion vector, wherein the shifted search window comprises a plurality of compared macroblocks; a search window memory, coupled to the search window offset detecting circuit, for selectively storing the plurality of compared macroblocks of the shifted search window; a motion vector detecting circuit, coupled to the search window memory, for selecting a reference macroblock from the plurality of compared macroblocks and outputting a compared horizontal motion vector and a compared vertical motion vector according to the reference macroblock and the first macroblock, wherein the difference between the first macroblock and the reference macroblock is minimum as compared with the difference between the first macroblock and other macroblock of the compared macroblocks; and a first adder for adding the predicted horizontal motion vector, the shifted horizontal motion vector, and the compared horizontal motion vector to generate a horizontal component of the output motion vector of the first macroblock of the first frame.