Lossless frame memory recompression for video codec preserving random accessibility of coding unit

In recent video applications such as MPEG or H.264/AVC, the bandwidth requirement for frame memory has become one of the most critical problems. Compressing pixel data before storing in off-chip frame memory is required to alleviate this problem. In this paper, we propose a lossless frame memory recompression scheme including 1) a lossless pixel compression algorithm, 2) an efficient address table organization method for random accessibility, and 3) frame memory placement scheme for compressed data to reduce the effective access time of SDRAM by suppressing row switching. Experimental results show that the proposed method reduces the frame data to 48% compared to that of the uncompressed one with H.264/AVC high profile encoder system, where 6.1 kB of SRAM is required for the address table of full HD video.