Fast Inter Prediction Algorithm For Hevc

The goal of next-generation digital video coding standard HEVC is to achieve video stream bit rate reduction by50%compared to H.264/AVC High Profile with same video quality. However, with HEVC’s improvement on coding performance, the complexity is greatly increasing. As a result, HEVC cannot satisfy the demand for real-time high-definition video encoding. In the hybrid video coding structure, the complexity of inter prediction accounts for above50%in the whole complexity, so the inter prediction acceleration can effectively reduce the whole encoder complexity.This paper focuses on HEVC encoding complexity and coding gain of the coding tools, so as to find out the module which contributes the most to the encoder with the highest complexity. By the analysis of inter prediction process, we propose a fast CU depth position method to end the recursive division of CU. The method is based on Skip mode. Experimental results show that encoding time is reduced significantly without much encoding performance loss.In this paper, we also propose a novel motion compensated prediction framework which combines the properties of motion vector restriction and weighted advanced motion vector prediction (AMVP) to achieve higher prediction accuracy for High Efficiency Video Coding. In our framework, motion vectors of the prediction units surrounding the current PU are checked first by a motion field model, and the geometric relationship between motion vectors of the current PU and its neighboring coded PUs is analyzed. Then whether to use the weighted AMVP prediction method is determined by the motion vector restriction criterion. If the current PU is coherent with the neighboring PUs according to the motion vector restriction process, the Merge/Skip mode prediction is adopted. If the current PU and its surrounding PUs do not belong to the same object in terms of motion vector restriction, the proposed weighted AMVP prediction is employed. Experimental results show that the proposed framework achieves BD-PSNR increment as well as encoding time saving without extra side information signaled.