Fast Inter Coding Unit Splitting Algorithm For HEVC

Compared with previous video coding standards,High Efficiency Video Coding(HEVC)can achieve better compression performance and coding quality.But the huge amount of computation in the coding process brings great challenges to the design of the encoder.Moreover,the complexity of Inter Coding Module occupies 70% in the HEVC coding architecture.Therefore,in order to reduce the computational complexity and accelerate the coding process,it is of great practical significance to study the acceleration technology of HEVC inter coding.In this paper,we study the fast inter coding method based on the existing HEVC coding technology.Starting with the tree structure of inter coding unit splitting method,we analyze each grammatical unit in the quadtree structure,the rate distortion optimization method,and the coding unit splitting process of inter coding.And the complexity of existing HEVC inter coding unit splitting method is discussed.Then,based on the analysis of video sequences with different scenes and motion features,we establish the relationship between the partition mode of inter coding unit and the spatio-temporal correlation.On this basis,a Fast Inter Coding Unit Splitting Method for HEVC is proposed.According to the spatio-temporal characteristics of inter coding unit splitting method,we propose two coding unit(CU)depth range predict ion algorithms from the FRAME level and the coding tree unit(CTU)level respectively.By setting a reasonable CU depth range at the beginning of the quadtree structure,the inter coding system can avoid unnecessary CU depth,so as to reduce the complexity of the encoding process.Next,in order to further accelerate the process of HEVC inter coding unit splitting,we analyze the selection process of CU prediction mode.After that,we propose a fast selection algorithm of CU prediction mode on the basis of the obvious tendency of the selection process.Based on the HM 16.5 platform,the performance evaluation of the proposed Fast Inter Coding Unit Splitting Method for HEVC is carried out in this paper.At the average bit rate increase of 1.37% and the average PSNR reduction of 0.11 d B,the proposed method achieves 42.52% coding time saving on average,achieving a good performance in the optimization of the existing HEVC inter coding technology.