Speeding Up the Decisions of Quad-Tree Structures and Coding Modes for HEVC Coding Units

High Efficiency Video Coding (HEVC) is being developed by the joint development of ISO/IEC MPEG and ITU-T Video Coding Experts Group (VCEG) and is expected to be a popular next-generation video codec in the future. HEVC can provide higher compression ratio compared to H.264/AVC standard; however, the coding complexity is dramatically increased as well. In this thesis, a fast algorithm for coding unit decision is proposed to reduce the burden of the encoding time in HEVC. The proposed algorithm exploits the temporal correlation in the neigh-boring frames of a video sequence to avoid the unnecessary examinations on CU quad-trees. In addition, based on an adaptive threshold, the best prediction mode is early determined to SKIP mode for reducing the exhaustive evaluations at prediction stage. The performance of the proposed algorithm is verified through the test model for HEVC, HM 5.0. The experimental results show that the proposed algorithm can averagely achieve about 27%, 33%, 20%, and 21% total time encoding time reduction under Low-Delay High Efficiency, Low-Delay Low Complexity, Random-Access High Efficiency, and Random-Access Low Complexity configurations respectively with a negligible degradation of coding performance.