Patent ID: 6904093

Claim:
An apparatus for changing a horizontal or vertical scanning frequency in a decoding block for restoring an MPEG signal including a prediction memory for storing I picture data and forward prediction restored P picture data and a mean operating unit for generating calculated mean data for bidirectional prediction, comprising: a B picture memory for storing B picture data, the B picture data having been bidirectionally prediction restored by the decoding block; a prediction memory switching portion for switching the I picture data, the P picture data and the B picture data output from the decoding block to the prediction memory or the B picture memory depending on the type of picture; and an output data switching portion for performing switching control to increase a frequency with which data is output from the prediction memory and the B picture memory with respect to a general scanning method, using a motion vector of the decoding block, and outputting the data, wherein the output data switching portion performs the switching control so as to repeat data of a corresponding horizontal line of a previous picture between horizontal lines of a picture when the value of a motion vector is no more than a reference value and to insert corresponding line data of a previous picture stored in the prediction memory between the horizontal lines of the picture when the value of the motion vector is larger than the reference value.