Study On Reference Frame Setting And Fast Block Parition Algorithm For New Generation Video Coding Standard HEVC

In March2013, the next generation video coding standard High Efficiency Video Coding(HEVC) was officially released, jointly developed by the ITU-T Video Coding Experts Group(VCEG) and the ISO/IEC Motion Picture Coding Experts Group (MPEG). As a successor ofH.264/MPEG-4Part10AVC, HEVC is also based on the traditional hybrid video codingframework with using many advanced technologies, including block division on quadtree, upto32×32size transformation block, a more sophisticated intra-prediction mode, brand newmotion merge technology, high efficiency context-based adaptive binary arithmetic coding, etc.With the help of these technologies, the HEVC compression performance has been nearlydoubled, and especially suitable for high-resolution (e.g.4K,1080p) video compression.Though the compression performance of HEVC improves, meanwhile, its computationalcomplexity several times increases, which largely affects the promotion of this standard. Inorder to reduce encoding time, two issues are focused in this paper. One is the setting of multiplereference frames. Through studying the distribution of reference frames under the HM low-delay configuration, we found that for the two high QP images, reference points of more than97%area focus on the former two and three reference frames. Therefore, a new simplifiedmedhod that one and two reference frames are discarded for the two high QP picturesrespectively is proposed in this paper. Test results show that the encoding time can be reducedby9.5%on the basis of the existing fast algorithms in HM13.0, while the BD-rate increasesonly0.57%.The second issue is the partition of coding unit. The encoding time greatly increasesbecause of the flexible size of coding unit. In this paper, through further study the existing blockpartition algorithms in HM, an improved Early Termination algorithm aiming at low-delayconfiguration is put forward. In this new algorithm, the rate-distortion cost of various sizeblocks in low QP images is used to obtain the threshold, and the update strategy of the rate-distortion threshold is simplied. The results show that for the propose algorithm the encodingtime can be decreased by12.7%on the basis of the exsiting fast algorithm, while the BD-rateraised about2.4%.This paper is organized as follows: The first chapter introduces the basic principles of videocoding, historical standards, as well as the current research hotspots of HEVC, etc. The secondchapter elaborates the key modules of HEVC and lays the foundation for the further parts of this paper. The third chapter analyzes the multiple reference frames techniques, proposes asimplified reference frame setting solution for the low-delay configuration and gives theexperimental results. The forth chapter studies the coding unit division and mode selectionalgorithm, put forward an improved “Early Termination” algorithm,and The performance of theproposed algorithm is tested and verified.