Research For Error Concealment Algorithm In Wireless Video Communication Based On H.264

With the rapid development of digital compression and network communication technology, especially the wireless communication technology, the video service has infiltrated into many areas. The video information processing and transmission in the wireless network has also become one of the research hotspot.As we know, the inherent problem in communication system is that physical channel is not error-free channel. And compared with the cable channel, the existence of some defects in wireless channel, such as high bit error rate and instability transmission environment, which will inevitably lead to data errors and lost, etc. In addition, the compression ratio has been improved because of the predictive coding technique which is widely used in the existing video compression standard. But at the same time, the relevance of the data has been reduced, so that video streams are more sensitive to the errors. Once there is transmission errors occur, the spread of errors will lead the reconstruct image to a sharp decline. Therefore, in order to get image which can be accepted by the human visual, the video error control technology has to be taken in the decoder.In this article, It first summarize the principle of video compression, and introduce the features of next-generation video compression coding standard—H.264. Then, take an overview of video communication technology and error control technology in H.264. After that, focus on the error concealment technology in decoder and some existing algorithms. At last, improve the error concealment algorithm in time-domain and spatial-domain:①It presented an efficient temporal error concealment algorithm which based on improved flexible macroblock mode of H.264. And realize the algorithm in the official codec—JM. Then take the experiment in wireless channel model. Simulation results under 3GPP/3GPP2 wireless channel show the proposed method performs better quality than other approaches with the same RTP packet loss rate.②It presented a spatial error concealment algorithm which based on the classification strategy of error block. The algorithm can adaptively classify the error block into smooth, texture and edge block by the gray and gradient characteristics of pixels around the error block. The experimental results showed that the algorithm has better performance than other algorithms, and point out its application environment.