Research On Fast Selection Algorithm For CU Partition And RDO Optimization Algorithm In AVS2 Intra-predection Encoding

The video part of AVS2 (Audio Video Standard Ⅱ) one of second generation of source coding standards and own independent Chinese intellectual property rights was set up in 2011, showing that our country’s development in the field of video coding is a step closer. Considering the compression efficiency, AVS2 has doubled than AVS1 and has been comparable to the international popular video coding standard HEVC.AVS2 video standard is mainly used in high definition video, and AVS2 has a great industrial value in the field of video surveillance. On March 15,2016," High Efficiency Audio and Video Coding-Part 1:Video" has licensed to SARFT. It Will be released as a radio and television industry standards in the near future. Although AVS2 has been close to the development and publication of the final version, it is stil need to constantly improve and have great research value.Firstly, this paper introduces the intra predection of AVS2 and the reference software RD7.0 of AVS2 in detail.It is found that the coding complexity of CU mode selection of the quadtree recursive structure and the PU mode selection is very high, which is the main reason of the influence of the coding efficiency.This paper focuses on the selection of CU partition and the RDO process and proposes a CU partition early termination algorithm based on spatial correlation.According to the comparison of the best CU partition of the coded unit that has been around the coding CU and Distortion,then decide the optimal CU partition quickly,reducing the encoding complexity and improving the encoding efficiency.Then, according to CU partition ahead of schedule to optimize the RDO process, select rational Lagrangian multipliers in view of the different size of CU, saving rate, reducing the transmission bandwidth required.In this paper, a lot of experiments and statistics have been done on different video sequences under several QP.The CU partition early termination algorithm can greatly reduce coding time about 20%.The RDO optimization algorithm based on CU ahead of schedule makes coding bit rate drop about 6%.Finally, this paper combines the CU partition early termination algorithm and RDO optimization algorithm.And a lot of experiments and statistics have been done on different video sequences under several QP.The combination of two algorithm reduce coding time about 22%.and reduce coding bit rate about 5%.