A method for finding a variable length code set under the constraint of maximal clock rate is presented. Given a probability vector and requiring that the length of codewords would be an integer multiple of some

reduces the maximal clock rate needed in implementing the compression system. On the other hand, given a maximal clock rate, the method enables us to use a quantizer with more levels than the usual Huffman code affords. The increase in the average transmission bit rate is practically negligible.