Research On Efficient Algorithms For The Selection Of Intra-predection Modes In AVS2 Encoding

It has been four years since the project of the national standard of AVS2-P2(video part) was set up in 2011. The working group has been continually improving the video coding standard of AVS2 during these years to make it comparable to the international video coding standard HEVC, which is prevailing all around the world nowadays. As we own the intellectual property rights of AVS2, there’s no need for us to pay much patent fees for this technology, and the popularity of AVS2 seems to be just around the corner. Therefore, the research, optimization and improvement of AVS2 video coding standard has great significance.The thesis introduces the video encoding frame and the frame types of AVS2 as well as the block structure at first. Then it makes a thorough explanation of the key technology and innovation of AVS2 video coding from five aspects of intra prediction, inter prediction, transform, entropy coding and loop filter.Secondly, the thesis introduces the fast mode decision algorithm for intra-prediction in reference software RD7.0 of AVS2 in detail. This algorithm includes two aspects:RMD process and RDO process. According to the relevant literature of HEVC and the strong correlation of pixel between the neighboring blocks, we propose the intra-prediction fast mode decision algorithm based on MPM for AVS2 coding video standard. The algorithm reduces the number of modes of RMD, thereby reducing the coding complexity and improving the coding efficiency.Finally, the thesis proposes the intra-prediction fast mode decision algorithm based on the size of PU. At first, we calculate the probability of the best mode in nine kinds of candidate modes in terms of different sizes of PU. Then we analyze the statistics and propose the intra-prediction fast mode decision algorithm based on the size of PU. After that, algorithm is simulated and the simulation results are analyzed. Finally we combine the intra-prediction fast mode decision algorithm based on MPM and the intra-prediction fast mode decision algorithm based on the size of PU so as to further reduce the encoding complexity and significantly reduce encoding time.