Fast codebook search method for MPEG audio encoding

A fast codebook search method for finding an optimal Huffman codebook from a group of Huffman codebooks, wherein the method is especially suited for MPEG-compliant audio encoding. In order to select an optimal codebook from among candidate codebooks for a given sub-region, a bit difference table is created, which for any given data pair contains a bit difference value. The bit difference value is the difference between the number of bits needed for a given data pair (or quadruple) in a first candidate codebook and a second candidate codebook [N bits-M bits]. By summing all such bit difference values for the data samples in a given sub-region, a quick determination can be made as to which codebook would encode the sub-region using the fewest bits (based on the size and/or sign of the sum(s)). For sub-regions having three candidate codebooks, two bit difference sums are calculated. For an implementation of the MPEG-1 Layer III Audio Encoding standard, only 20 bit difference tables are required in order to cover every possible combination of codebook candidates.