Optimization Implementation Of Fractional Pixel Interpolation In H.265/HEVC By SSE2Instruction Set

Video coding is the basis and core of Multimedia Technology. Ever since firstvideo compression standardization is established in the1990s, there have been manyvideo compression standardizations. The history of video compression standardizationhas been dominated by efforts to maximize compression capability. An increasing va-riety of services, the growing popularity of HD video, and the formats going beyondHD (e.g.,4K2K resolution) are creating even stronger needs for compression capa-bilities superior to that of video compression standardization before. In January2010,ITU-T Video Coding Experts Group (VCEG) and ISO/IEC Moving Pictures ExpertGroup (MPEG) thus agreed to establish new video compression standardization. Thefirst version of HEVC was finalized by the JCT-VC in January2013. Sub-pixel inter-polation algorithm is a key technology in video coding algorithm, which has impor-tant influence on video coding performance. In video coding standard H.265/HEVC,interpolation filters based on DCT are used to interpolate half pixel and quarter pixel,but it has very high computation complexity, especially for high definition resolutionvideo coding applications.Through the research, the encoding efficiency is improved while the code qualityremains the same in H.265/HEVC compared with the reference implementation inHM software to better meet the real-time requirement of video compression nowadaysproposed by the popular of high definition and ultra-high resolution video. In this pa-per, the main work and innovations are as follows:1. This paper traces the sub-pixel interpolation in video coding standard’s de-velopment and summarize the classic sub-pixel interpolation algorithm in existingvideo coding standards, including: linear interpolation, interpolation with contourstencils. We also analysis the interpolation theory, compare the interpolation kernelwhile experiment with different interpolation algorithms.2. A systematic study on feature detection based on sub-pixel of H.265/HEVCvideo coding standard was conducted. And the background of DCT-based interpola-tion filters is been introduced in detail. In HM version10, interpolation filters based onDCT are used to interpolate half pixel and quarter pixel, that is to say, it adopts“7q(1/4)+8h” DCTIF for1/4luma sample which means7-tap DCTIF {-1,4,-10,58,17,-5,1,0} and {0,1,-5,17,58,-10,4,-1} is used for quarter pixel and8-tap DCTIF {-1,4,-11,40,40,-11,4,-1} is used for half pixel. In this paper, the implementation ofH.265/HEVC video coding standard was optimized by SSE2instruction set. Experi-mental results demonstrate that our proposed method improves the computation effi-ciency for half pixel by342%and for quarter pixel by214%at most as comparedwith the reference implementation in HM software.