Patent ID: 7124429

Claim:
A video decoding apparatus comprising: a demultiplexer which demultiplexes multi-bit streams to extract a coded bit stream, the multi-bit streams including the coded bit stream having coded video information generated by coding a video picture, sync information, and header information containing important information representing a rule of coding a set of bit streams in coding the video picture; a decoder which decodes the picture bit stream; a sync signal detector which detects a sync signal from the bit stream, and informs said decoder of the sync signal; an error checker which checks an error based on decoded information of said decoder; and an important information construction device which constructs important information from the header information output from said decoder, and informing said decoder of the important information when said error checker detects an error, said important information construction device including: determination means for determining whether a picture being decoded is an arbitrary shape picture or a conventional shape picture; a header decoder which decodes header information and constructs important information, when the picture being decoded is an arbitrary shape picture; a first important information construction device which decodes important information from the doubled important information, when the picture being decoded is a conventional shape picture, and important information has been doubled; and a second important information construction device which, when the important information has not been doubled, decodes and restores important information from single important information, restoring important information containing all pieces of information within a range restorable by reconstructing the important information, and returns the restored important information as constructed important information to said decoder.