Patent ID: 6552674
Filing Date: 2003-04-22
Classification: H03M

Abstract:
A method of selecting variable length codes for encoding a plurality of symbols in a data stream comprising the steps of:determining a mapping of symbols to variable length codes as a bitstring; selecting an initial population of a predetermined number of the bitstrings; calculating for each bitstring of a current population of bitstrings a number of bits needed for encoding the data stream from the mapping of symbols to variable length codes and the frequency of occurrence of each symbol; applying a termination condition to the current population of bitstrings; if the current population of bitstrings passes the termination condition, selecting the variable length codes corresponding to the bitstring having the least number of bits needed for encoding the data stream; and if the current population of bitstrings fails the termination condition forming a next current population of bitstrings from the prior current population of bit strings by genetic manipulation of bitstrings of the current population, calculating for each bitstring of the current population of bitstrings the number of bits needed for encoding the data stream, applying the termination condition to the current population of bitstrings, and repeating the steps of forming a next current population of bitstrings, calculating the number of bits needed for encoding the data stream, and applying the termination condition and until the current population of bitstrings passes the termination condition.