Abstract: A variable length coder and a variable length decoder. The variable length coder comprises a plurality of shifters, each of which inputs a corresponding one of a plurality of codewords and a plurality of codelengths, rotates the corresponding codeword by a desired length for interconnection of the codewords and outputs masking bits designating a position of the corresponding codeword to be rotated, a first OR gate for ORing output codewords from the shifters, a second OR gate for ORing output masking bits from the shifters, a word/mask register for latching output codeword bits from the first OR gate when corresponding output masking bits from the second OR gate are enabled to "1", and an FIFO memory for storing an output of the word/mask register and outputting variable length-coded data.

Abstract: A motion compensator for restoring a digital image which includes a motion compensating controller for receiving motion vector data and outputting control signals, a data interface for shifting input data, first and second field motion compensators for interpolating and performing motion compensation for field vectors, a frame motion compensator for interpolating and performing motion compensation for frame vector data, and a first multiplexer for selecting the motion compensated signal to be output, such that receiving data of a motion search area is processed in multitude and the motion compensation is processed in real time.

Abstract: A scanning format converting circuit for converting video signals of the interlaced scanning form involving flickers into those of the progressive scanning form free of flickers using motion vectors included in the video signals. In addition to a general decoding construction, the scanning format converting circuit includes an additional motion compensating unit and an additional frame memory. The additional motion compensating unit serves to motion-compensate input video data sent from frame memories using motion vectors and thereby derives data to be interpolated so that the video data of the interlaced scanning form is converted into those of the progressive scanning form.