Quadtree brings extremely high computational complexity in high efficiency video coding (HEVC). Innovative works for improving quadtree structures to further reduce encoding time are stated in this paper. A novel quadtree probability mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and video content change. Secondly, a CU quadtree probability model is proposed for modeling and predicting CU partition based on the group of picture (GOP). Eventually, a CU quadtree probability update is proposed, aiming to address probabilistic model distortion problems caused by video content change. Experimental results have shown that the proposed CU quadtree probability mechanism significantly outperforms HEVC by considerably reducing encoding time by 27% for lossy coding and 42% for (visually) lossless coding, without compromising rate-distortion (RD) performance.
['Yuan Gao', 'Pengyu Liu', 'Yueying Wu', 'Kebin Jia']
HEVC Fast CU Encoding Based Quadtree Prediction