Patent ID: 6862320

Claim:
An image decoding apparatus for decoding a first coded bit stream into which first header information and image coded data encoded in a first coding scheme are multiplexed, or for decoding a second coded bit stream into which second header information and image coded data encoded in a second coding scheme are multiplexed, said image decoding apparatus comprising: coding scheme decision means for making a decision as to whether a received coded bit stream is the first coded bit stream or the second coded bit stream and outputting a coding scheme identifier accordingly, based on a start code of a first kind included in the first header information or a start code of a second kind, different from the start code of the first kind, included in the second header information on the same layer as the start code of the first kind, the first header information further including first image coding information and the second header information further including second image coding information, wherein the coding scheme identifier is used to switch between alternative decoding steps for decoding the image coded data in the first coded bit stream or the image coded data in the second coded bit stream.