Decompression processor for video applications

Abstract

A method and structure including four video decompression structures and eight memory banks are provided for decoding high definition television (HDTV) signal. In this HDTV decompression structure, the 1920.times.1080 pixel display space is divided into four vertical sections of 480.times.1080 pixels. Each memory bank stores the values of pixels in one non-overlapping group of 240.times.1080 pixels. Each decompression structure decodes a 480.times.1088-pixel picture area with access to up to two additional 240.times.1088-pixel picture areas. The video decompression structures decode the vertical sections in lock-step to avoid the problem of the same bank of memory being accessed by more than one video decompression structure. In one embodiment of the present invention, a macroblock fetch can cross 1-4 DRAM page boundaries. So, in order to maintain the lock-step relationship of the video decompression structures, each page mode access is limited to fetching only an 8.times.8 quad pixel picture area, so that regardless of the number of DRAM page boundaries required to be crossed, four page mode access cycles are required for each reference macroblock fetched.

Dependencies are inferred from the claim text.