HEVC DCT-based Fast Intra Prediction Algorithm And Optimization

High Efficiency Video Coding (HEVC) is the next generation video coding standard after H.284/AVC, it aims to achieve higher video coding efficiency and enable the use of the coded video representation in a flexible manner for a wide variety of network environments, meeting the demand for high-quality video. HEVC retained the framework of hybrid video coding and adopted many technologies of video coding in recent years. Flexible coding unit and multi-angle prediction are adopted including coding unit, prediction unit, transform unit and35prediction modes. However, the introduction of these new technologies to improve the coding performance, while improving the coding complexity.In order to reduce the computational complex of HEVC encoder, in this thesis two fast HEVC intra prediction algorithms are studied and optimised. First, for the quadtree splitting of CU, this thesis studies and optimises a fast CU splitting algorithms based on Discrete Cosine Transform(DCT), In CU, analysise the relationship between the Low-frequency AC components and texture complexity, the texture complexity of CU determined by the Low-frequency AC components and rate-distortion cost, Thus early terminate the split of CU. Secend, for the35prediction modes, in this thesis judge the edge orientation of PU and choose the candidate modes of rough mode decision and rate-distortion optimization by DCT edge features. Then, analyzed the statistics generated by rough mode decision (RMD) process, Further to decrease the candidate modes for rate-distortion cost calculation.Experimental results show that the encoder computational complexity can be downscaled to30.14%and24.88%with little bit rate increase and little PSNR decrease.