Low-complexity multi-standard variable length coding decoder using tree-based partition and classification

MPEG-2 and H.264/AVC use variable length coding (VLC) to remove statistical redundancy. Representing the codeword table efficiently is thus an important issue to reduce hardware complexity, especially for multi-standard applications. In this study, the VLC tree is decomposed using sub-tree classification. The proposed algorithm reduces the amount of storage required for codewords. The proposed MPEG-2/H.264 VLC decoder has 11.9 K gates when synthesised to operate at 180 MHz. The gate count is 20% lower than the sum of gate count of individual H.264 and MPEG-2 VLC decoders.