SELECTIVE COMPRESSION NETWORK IN MPEG COMPATIBLE DECODER

摘要

PURPOSE: A selective compression network in an MPEG compatible decoder is provided to accept SD television signals, in either NTSC, PAL or SECAM format, which are rearranged into pixel blocks acceptable to the display processor so that a display processor accept pixel block formatted video data and produce display drive signals. CONSTITUTION: An MPEG decoder(14,18,22) in a high definition television receiver decodes and decompresses MPEG coded data to produce decompressed image pixel blocks, and includes a motion compensation network(90) coupled to a frame memory(60) to produce finally decoded pixel data for display. The decompressed MPEG data is recompressed by plural parallel recompressors(40,42) prior to storage in frame memory. Each recompressor receives a datastream of interleaved pixel data(24,27), and predicts and compresses interleaved pixel values(a,c) during each clock cycle, respectively(20,27). One of the recompressors(42) is de-energized in a reduced data processing mode when pixel data is subsampled(36,38) prior to recompression. Subsampled data is re-ordered(43) prior to recompression. Multiple parallel decompressors(80,82,84) coupled to the frame memory provide pixel data to the motion processing network. A control unit insures an uninterrupted interleaved data flow to the decompressors by repeating last valid data when source data is interrupted.