Research Of The Error Concealment Technology Based On H.264

Although the new generation of video compression coding standard H.264, because of its excellent compression performance, has been widely applied to video transmission communication services, the compressed video stream trabsnussion channel is vulnerable to the effects caused by errors or packet loss, even the entire video sequence is damaged. In order to improve the anti-error performance, error concealment technology becomes the research hotspot in recent years.Firstly, a brief descripition about the current research and development of the error concealment techniques at home and abroad is given, then analyze and discuss the history of H.264 standard and its new error resilience tools. Finally, based on the exploration of the classification of the error concealment thchnology, two key issues in this area are proposed, which are verified through analysis and simulation experiments. The main aspect we complete are as follows:(1) For I-frame, based on the research and analysis about the common spatial error concealment algorithms, an improved hybrid spatial error concealment is proposed. The algorithm, using the technology of flexible macroblock ordering which is one of the H.264 error resilence tools, adaptively adopts different error concealment algorithms to recover the error image based on the concept of directional entropy.(2) For P-frame, considering that the processing order of error blocks have an important effect on the improvement of concealed image quality, an improved adaptively enhanced temporal error concealment algorithm is proposed. The algorithm continuously estimates the order value of error macroblock(MB) using the received or concealed adjacent information, and only the error MB with the largest order value is restored at a time. When conceals an error MB, firstly determines its partition mode and the concealed order of its sub-macroblock(SMB), then chooses the best motion vector(MV) for the error MB or SMB from the candidate MVs, by adaptively use the single_sided or double_sided overlapping boundary matching algorithm based on texture(TBSS-OBMA or TBDS-OBMA). The experiment results show that the proposed algorithm can better improve the quality than others whether on the subjective or objective aspect in the same error environment, and the improvement of 1.16dB in PSNR can be achieved compared with JM12.2.