Fast decision of CU partitioning based on SAO parameter, motion and PU/TU split information for HEVC

Abstract

High Efficiency Video Coding (HEVC) has recently been standardized with a significant improvement of coding efficiency compared to its preceding video coding standards. To achieve high coding efficiency improvements, HEVC adopts deeper hierarchical block coding structures of coding unit (CU), prediction unit (PU) and transform unit (TU), to better adapt the complex texture and motion natures of various video sequences. However, this causes a dramatically increased computational and structural complexity of HEVC encoders and decoders. In this paper, we propose a fast decision method of CU partitioning, which significantly reduces total encoding time with negligible RD-performance loss for HEVC. For this, the proposed method effectively utilizes the available side information such as sample adaptive offset (SAO) parameter values, PU sizes, MV sizes and coded block flag (cbf) data, so that the required computational complexity for fast CU split decision is minimized. Our experiment results show that the proposed method reduces the total encoding time to average 43.2% only with average 1.58% bit-rate increase for ten test sequences of HEVC.