Patent ID: 8054889
Filing Date: 2011-11-08
Classification: H04N

Abstract:
1. An image decoding apparatus for decoding at least a first coded bit stream into which header information of the H.263 coding scheme and image coded data encoded in the H.263 coding scheme are multiplexed, or for decoding a second coded bit stream into which header information of the MPEG-4 coding scheme and image coded data encoded in the MPEG-4 coding scheme are multiplexed, the 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 in response to the first header information or to the second header information; two kinds of variable coded length tables for use in the decoding of the alternative current component of the DCT coefficient; a switch for switching to one of the two kinds of the variable coded length tables regardless of a coding type of a macroblock to which a DCT block belongs when the first coded bit stream is received and for switching to the variable coded length table selected according to a coding type of a macroblock to which a DCT block belongs when the second coded bit stream is received; and a decoding means for decoding the alternative current component of the DCT coefficient using the variable coded length table switched by the switch.