Key Technology Of Video Decoder Based On H.264

As digital video technology extensive application in the field of communications and broadcasting, the technology of multimedia information processing and transmission in network has become a research hotspot. H.264/AVC is the newest international video coding standard which was published in March 2003 by ITU-T/ISO. Compared with previous standards, the coding efficiency of H.264/AVC increased by about 50%,but the complexity of algorithm also increased. Therefore video codec must be optimized for better information transmission and storage.In this paper, we improved the original algorithm with two aspects by the optimization of CAVLC decoding and loop filtering algorithm in order to improve the decoding speed. Firstly, The fundamental principles of video coding and the main functional modules of H.264/AVC decoder are introduced .Then introduced the entropy decoding and adaptive in-loop filter which are time-consuming modules. Based on analysis some CAVLC decoding algorithms, a new CAVLC decoding algorithm which is the combination about grouping methods and the binary is proposed in this paper. After analysis the reasons of blocking effect and researched the filtering theory of loop-filter in H.264/AVC, according to the peculiar coding information in H.264, proposed a new mode which can maintain a more complete image detail without fuzzy in flat area and less filtering in complex area. Improving the standard algorithm by reduced the judgments number of Bs, changing the filtering order in macroblock. Finally, the simulation shows the algorithm without affect the image quality can indeed reducing decoder running- time and improve decoding speed.