Probability-Based Intra Encoder Optimization in High Efficiency Video Coding

The High Efficiency Video Coding (HEVC) adopts increasing number of intra prediction modes and Coding Unit (CU) partitions, in order to diminish its cost at required bitrates. However, its attendant computational complexity is unfavorable in lots of real-world applications. In this paper, we propose a probability-based strategy that benefits a lowcomplexity HEVC intra-encoder and also provides guidance to design low-complexity framework of next generation encoder. The proposed strategy comprises three steps: a candidate mode list initialization based on the estimated winning probabilities of all intra modes, an early termination of intra prediction based on the estimated probability of obtaining the best intra mode, and a pre-decision of Coding Unit (CU) split based on the estimated distributions of the Rate-Distortion (RD) costs. Comprehensive experiments have validated the effectiveness of the proposed algorithm, with a promising simulation performance under Common Test Conditions (CTC).

I. Introduction

To address the growing demand for high-definition and ultra-high-definition video, the state-of-the-art video coding standard High Efficiency Video Coding (HEVC) [1] was formally released in 2013 by the Joint Collaborative Team on Video Coding (JCT-VC). Compared with the previous generation video encoding H.264/AVC [2], [3], HEVC reduces 50% video bitrate under the same visual quality. However, the coding efficiency is achieved at the penalty of highly encoding complexity.