Fast intra mode decision in high efficiency video coding

In this thesis a CU early termination algorithm with a fast intra prediction algorithm is proposed that terminates complete full search prediction for the CU and replaced by CU early termination algorithm which determines the complexity of the CU block then on sent decision is made to further split or non-split the CU. This is followed by a PU mode decision to find the optimal modes prediction mode from 35 prediction modes. This includes a two-step process: firstly calculating the Sum of Absolute Differences (SAD) of all the modes by down sampling method and secondly applying a three step search algorithm to remove unnecessary modes. This is followed by early RDOQ (Rate Distortion Optimization Quantization) termination algorithm to further reduce the encoding time. Experimental results based on several video test sequences suggest a decrease of about 35%-48% in encoding time is achieved with implementation of the proposed CU early termination algorithm and fast intra mode decision algorithm for intra predication mode decision with negligible degradation in peak signal to noise ratio (PSNR). Metrics such as BD-bitrate (Bjontegaard Delta bitrate), BD-PSNR (Bjontegaard Delta Peak Signal to Noise Ratio) and RD curve (Rate Distortion) are also used.