H.264Error Concealment Technology Research In Video Decoding System

In recent years, the digital satellite TV technology and multimedia videotechnology has made rapid development, and people need higher quality of video.However, huge amount of data in video information and huge bandwidth resourcewhich transmission needs bring challenges for transmission and storage of videodata. Therefore, a more advanced compression technology H.264came into being, thecaused problem is that compressed video stream becomes extremely sensitive to BER,making the error quickly spread in spatial and temporal domain, leading to a seriousdecline in quality of video. When BER occurs, error concealment of video imagebecome the best way to resolve. So error concealment technology has attracted a largenumber of researchers by its practical value.Compared to Previous video compression standards, H.264has highercompression efficiency, sharper image quality, greater adaptability of the networkand better error resilience performance. This paper introduces H.264developmentstatus error concealment technology, and the basic concept firstly. and then describesthe structural characteristics of the H.264video compression technology, grade andlevel codec framework, as well as several key technologies: intra prediction, interprediction, integer transform and quantization and entropy encoding and decoding,blocking filtering. After then analysis of the current temporal and spatial errorconcealment techniques is given.Aiming at lack of edge processing in error concealment of H.264, this paperproposes spatial EC algorithm based on the edge of the analysis. At first, analyzingthe edge type, and selecting the appropriate bilinear interpolation method based ondifferent type of edge. This method takes obvious improvement on the details ofimage. To the temporal EC, proposing a directional boundary matching algorithm, andmulti-mode adaptive superimposed on the basis, which can reduce the error of modemisjudgment. At last, a scene change detection technology is proposed, selectingappropriate EC algorithm depending on the judgment, which increasing the accuracyof EC.This paper is based on the JM15.1,which is experimental platform of H.264international standard code, and make comparison with MMAO algorithm ofreferences. Making discussion of three aspect which include subjec tive effect of video images, objective quality and the computational complexity. Combined withtheoretical knowledge to analyze the simulation results, we can see the proposed errorconcealment algorithm play a certain effect on the video quality improveme nt, takingthe acceptable time consideration for exchange.