Multiple Early Termination for fast HEVC coding of UHD content

The recently ratified High Efficiency Video Coding (HEVC) standard is significantly outperforming previous video coding standards in terms of compression efficiency. However, this comes at the cost of very high computational complexity, which may limit its real-time usage, particularly when targeting Ultra High Definition (UHD) applications. In this paper, an analysis of HEVC coding on UHD content is presented, showing that on average more than 18% of the total encoding time is spent performing uni-directional Motion Estimation (ME) even when using fast algorithms such as Enhanced Predictive Zonal Search (EPZS). In order to speed up the ME process, a novel approach for fast inter prediction is proposed in this paper based on a Multiple Early Termination (MET) decision process. EPZS is only performed in blocks in which it is needed based on local features of the encoded content, or it is skipped otherwise. Experimental results show that the algorithm achieves on average 9.3% speed-ups over conventional HEVC, at the cost of very small BD-rate losses.