Patent ID: 7558324

Claim:
Picture encoding method for generating a bit stream, the bit stream being compatible with MPEG 1 moving picture video standard and comprising an extension byte in at least a header of a picture layer of the bit stream, the extension byte being extension data added when a header includes control data newly added in MPEG 2 moving picture video standard format, the method comprising the steps of: storing an extension byte of an anterior header of said specified layer; comparing an extension byte of a current header of said specified layer to the extension byte of said anterior header; and transmitting extension byte of said current header is different from the extension byte of said anterior header, the extension byte of said current header and an extension start code indicating the beginning of the extension byte of said current header, and not transmitting, when the extension byte of said current header is the same as the extension byte of said anterior header, the extension byte of said current header and an extension start code indicating the beginning of the extension byte of said current header.