Study On The Technique Of Fast Inter Frame Coding For HEVC

HEVC is the new generation of video coding standard for high definition video applications. HEVC has shown significant advances in compression efficiency and outperforms the existing H.264/AVC high profile by 50% bitrate reduction at the same reconstructed video quality, but one magnitude more computational complexity. Therefore, the fast coding technique for HEVC has significant importance in its future applications. Inter frame encoding is one of the crucial techniques of HEVC coding framework, its fast coding algorithms are hot issues for many researchers. This thesis has conducted studies to the inter PU mode selection and the quad-tree division for CU in HEVC standard in deepth, proposed three fast altorithms for inter frame coding of HEVC. The main work and innovation are as follows.(1) The optimization algorithm for Merge mode which is a part of the process of the selection for interframe PU mode is proposed. It reduces the number of candidate list in Merge mode processing and simplifies the traversal times of the best candidate parameters by removing redundant zero vectors candidate and the parameter GMV be used to remove the the uneffectiveness of the remaining candidates. Experimental results show that the increment in bit rate of the proposed method is 0.7% in LD and 0.47% in RA configuration, respectively. And the saving time of Merge mode process is about 60%, but the saving time of encoder is only about 8.7%.(2) The further optimization for the AMVP mode which also is an inportment part of the selection for interframe PU modes is done. The method uses SKIP mode and the temporal correlation to reduce the number of execution of AMVP mode. The coding time of AMVP mode is about 9 times that of Merge mode, the process of AMVP mode can be skipped for CU which texture and motion is simple. This method uses the SKIP mode early termination condition and the temporal correlation to skip the AMVP process of some sub prediction units. Experimental results show that the coding rate of the proposed algorithm were increased on average by about 1.36% and 0.89% in LD and RA configuration. The average saving time of encoder achieves 42%.(3) A fast CU depth partitioning algorithm is proposed based on the interframe PU modes classification. The seven inter PU modes is divided into three categories, which represent different categories of the complexity of texture and motion. The movement of the current CU is Judged by the PU mode classification and the values of CBF and MVD, the CU which texture and motion is simple will be early termination. The proposed scheme provides 42.84% encoder time savings in RA configuration and 51.51% time savings in LD configuration on average, and its increment in bit rate is 0.236% in LD and 0.56% in RA compared to the default encoding scheme in HM10.0.Finally, the thesis summarizes the work in the study and describes possible directions for future work.