Simultaneous search for different resync-marker patterns to recover from corrupted MPEG-4 bitstreams

摘要

An error-resilient decoder for motion-picture-experts group (MPEG-4) video detects variable-length resync markers together with video packet (VP) headers at the start of each video packet in a video object plane (VOP). An f_code in the VOP header indicates a motion-vector search range and a bit length for all resync markers in the VOP. When the f_code is correctly read, the bitstream is searched for a fixed-length resync markers. However, when an error occurs in this f_code, the length of the resync markers is unknown. A multi-pattern resync marker and VP header decoder searches the bitstream for one of 7 patterns for each possible resync marker bit-length. A match allows the VP header and data to be decoded even when bit errors occur in the VOP header. Faster recovery occurs for corrupted bitstreams such as those transmitted over wireless networks.