The invention provides a sub-pixel
motion estimation device and a method therefor; the device comprises a
macroblock storage unit to be estimated, a
reference frame storage unit, a sub-pixel prediction block generation unit, an arithmetic and logic array unit, an SAD accumulation unit, an
optimal matching decision unit and a mode deciding unit, while another pattern of the device comprises the
macroblock storage unit to be estimated, the
reference frame storage unit, the sub-pixel prediction block generation unit, the arithmetic and logic array unit, the SAD accumulation unit, a mode select unit and the
optimal matching deciding unit. The invention balances the search range and the search accuracy of the
motion estimation, lowers the calculating complexity, shortens the search time, ensures the instantaneity of a coding
system, the whole
motion estimation operation is performed in a
short cycle, less resources are occupied without damaging the coding performance, little
impact is imposed on compression efficiency of an
encoder, so that choices can be made by weighing and balancing among performance,
power consumption and area of the
encoder; in addition, the device and method of the invention have strong versatility and
reusability.