Robust Mode Mismatch Macroblock Retrieval Algorithm for Transcoding MPEG-2 to MPEG-4 in Compression Domain

MPEG-4,as one of the most promising and advanced compression standard,will be leading the video transmission, storage,and edition applications in the coming future. But two excellent standard-compliant streams,MPEG-2 and MPEG-4 video, will be coexisting in different systems for a long time. This paper addresses the issues of transcoding MPEG-2 video to MPEG-4 compliant bitstream in compression domain to meet low complexity and low latency real-time application. The key issue about macroblock coding mode mismatch in transcoding processing will be discussed in detail. The reported simulation results testified that the proposed transcoding algorithm could not only convert MPEG-2 stream to MPEG-4 steam effectively, but also retrieve or conceal the mismatched macroblock robustly,which will improve the perceptual quality greatly.