High speed search and memory efficient Huffman coding HDTV

Code compression is a key element in high speed digital data transport. A major compression is performed by converting the fixed-length codes to variable-length codes through a (semi-)entropy coding scheme. Huffman coding combined with run-length coding is shown to be a very efficient coding scheme. To speed up the process of search for a symbol in a Huffman tree and to reduce the memory size, a tree clustering algorithm is proposed to avoid high sparsity of the tree. The method is shown to be very efficient in memory size, and fast in searching for the symbol. For an experimental video data with Huffman codes extended up to 13 bits in length, the entire memory space is shown to be 126 words, compared to normal 2¹³ = 8192 words