METHOD OF CONVERTING BIT RATE OF COMPRESSED VIDEO BIT STREAM THROUGH CODEWORD EXCHANGE

摘要

PURPOSE: A method of converting the bit rate of a compressed video bit stream through codeword exchange is provided to convert the bit rate with a small amount of conversion loss. CONSTITUTION: An exchange codeword determination unit(304) selects a codeword that replaces the codeword of an input bit stream. A codeword exchange unit(306) exchanges the codeword of the input bit stream with the codeword selected by the exchange codeword determination unit. The exchange codeword determination unit selects the codeword having the shortest code length among candidate codewords that satisfy conditions that run lengths of two codewords before and after being subjected to exchange are identical to each other and the levels of the two codewords have a predetermined difference between them.