Abstract: In this work, two schemes are proposed to improve the memory performance in video decoder systems. A novel lossless frame recompression method and an efficient frame storage mapping strategy are employed to reduce the Read/Write and Row Activation operations of the external memory during video decoding processes. Verified with MPEG-2 based HDTV video decoder, the number of bytes writing to the memory is reduced by about 50% in comparison with the conventional decoder using the embedded frame recompression algorithm, without video quality degradation. Moreover, the reading bytes from off-chip memory for motion compensation are not increased. Additionally, by storing the luma and chroma components of one macroblock in one row of different banks, as well as the ten neighboring macroblocks, the logic Row Activation number can be cut down to nearly 5% of the conventional linear storage scheme.

Key words: video decoder, memory optimization, memory compression, lossless frame recompression, frame storage mapping