High-speed motion vector decoding circuit

Abstract

A high-speed motion vector decoding circuit which decodes a motion vector formatted according to the MPEG-2 standard. The motion vector decoding circuit implements a motion vector decoding method on dedicated hardware including a pipeline structure. The hardware includes a parameter store for storing the input motion vector decoding parameters, that is, a motion vector range determination code, a motion vector code, and a motion vector residual code. The hardware also includes a motion vector decoder for storing motion vector to be decoded as a previous motion vector and decoding the motion vector using the parameter stored in the parameter store and the previous motion vector, a dual primer for receiving the previous motion vector stored in the motion vector decoder and generating a predetermined number of dual motion vectors, and a motion vector controller for controlling the operations of the decoder via the input parameters, and selecting and outputting the previous motion vector or the dual motion vector, as a finally decoded motion vector. A six-clock period of time is needed to decode one motion vector, and a 6+(n-1)-clock period of time is needed to decode n motion vectors via the pipeline structure, which enables the decoding circuit to be applied to a high-speed system such as a high-definition television.