Patent ID: 6829299
Filing Date: 2004-12-07
Classification: H04N

Abstract:
A video decoding apparatus comprising:an input unit which receives encoded data of a video signal containing a variable length code generated by encoding transform coefficients obtained by orthogonal transformation of the video signal by using code words that can be decoded in both a forward direction and a backward direction; a sync section detection unit which detects a sync section of the encoded data; a forward decoder which decodes encoded data in the forward direction in a predetermined sync section detected by said sync section detection unit; a backward decoder which decodes encoded data in the backward direction in a predetermined sync section detected by said sync section detection unit; and a decode value determination unit which outputs a final decode result from decode results obtained by said forward and backward decoders, wherein each of said forward and backward decoders includes an error detection unit for detecting an error in the encoded data, and said decode value determination unit determines a decode value by using an error detection position in the encoded data in units of bits and an error detection position in the decoded data in units of syntax, which are detected by said forward decoder and indicate an error position in the encoded data, and an error detection position in the encoded data in units of bits and an error detection position in units of syntax, which are detected by said backward decoder and indicate an error position in the encoded data, wherein when an error is detected in the encoded data in the sync section, said decode value determination unit discards parts or all of encoded data composed of macroblock transform coefficients having undergone intraframe encoding within a macroblock in which no error has been detected.