Patent ID: 8175159

Claim:
A method of coding a moving picture, comprising: dividing a picture into a plurality of coding blocks; predicting a motion vector of a coding block from a motion vector of a block adjacent to the coding block as a predictive motion vector; calculating a differential motion vector (MVD) based upon a motion vector (MV) to be coded and a predictive motion vector (PMV) of the motion vector to be coded per block by subtracting the PMV from the MV to obtain a first value and applying an arithmetic right bit shift to the first value according to an my shift value to obtain the MVD; selecting a type of accuracy of a differential motion vector among a prepared plurality of types of accuracy of a differential motion vector for each coding block in conjunction with determining the my shift value for calculating the MVD, the plurality of types of accuracy including 1-pixel accuracy and smaller fractional-pixel accuracies; and coding information of the selected type of accuracy and the differential motion vector calculated with the selected type of accuracy.