Research On Error Control Technology Of Video Transmission Based On H.264

In recent years, with the development of electronic technology, computer scienceand network technology, video communication on the network was applied widely. A lot of network multimedia services appeared. With the wide application of video communication, errors and losses of video data are inevitable whether in IP network or wireless network. The highly compressed video data are more sensitive for errors, and a bit errors can ultimately lead to uncountable errors, so it is necessary to add effective error control technology into the encoder and add error concealment into the decoder of a video communication system.H.264/AVC is the newest international video coding standard. It was named H.264 by the ITU-T Video Coding Experts Group, and the ISO/IEC Moving Pictures Experts Group named it as ISO 14496-10(i.e. the 10th part of MPEG-4). The main purpose of this standard is to enhance the efficiency of image compressing and improve the transmission quality of image data in the network. Under the same image quality, the bit stream of H.264 is greatly lower than that of the former standards such as H.263 and MPEG-4 (the second part). However, this compressed stream is sensitive to the data errors. Once the current image frame be mangled, the errors will diffuse rapidly in the time and frequency domain so that a large number of video signals would be influenced, that will bring severe descent of the video quality. The market requirement of the multimedia service is presented a fast increasing tendency, while the existing network without enough bandwidth and better Qos guarantee easily generate inference like packet loss. Thus, it is absolutely necessary to adopt effective error control to recover the false video signal when the video code transfers in the low-dependable channel.This paper reviewes the background and the development course of video compression coding standard, and introduce the new technologies of H.264 standard differing from the previous versions. Made an in-depth study of theresilience tools in H.264 such as flexible macroblock order (FMO), parameter sets, data partition, and described different modes of FMO in detail. The paper puts the emphasis on the temporal error concealment. Under analyzing the characteristics of several traditional temporal error concealment algorithms, we propose an enhanced weighted boundary matching error concealment algorithm based on multiple-reference frames to conceal and recovery the errors. Proved by experiments, this algorithm can restrain the pervasion of the boundary video error effectively, and achieve a better error concealment effect comparing to the traditional error concealment algorithms.