An MCMC based Efficient Parameter Selection Model for x265 Encoder


As an open-source and computationally efficient High Efficiency Video Coding (HEVC) encoder, x265 has been gaining increasing popularity in video applications. x265 provides numerous encoding parameters in view of flexibility. However, proper and efficient setting of parameters often becomes a great challenge in practice. In this paper, we deeply investigate the influence of x265 parameters based on the Slow preset and pick out important parameters in terms of efficiency and complexity. Then a Markov Chain Monte Carlo (MCMC) based algorithm is proposed for efficient parameter adaptation at the target encoding time. This paper shows that carefully selected lowcomplexity encoding configurations can achieve the coding efficiency comparable to that of high-complexity ones. Specifically, average 26.72% encoding time reduction can be achieved while maintaining similar Rate Distortion (RD) performance to x265 presets using the proposed algorithm.

2018 IEEE International Symposium on Circuits and Systems (ISCAS)
Li Song
Li Song
Professor, IEEE Senior Member

Professor, Doctoral Supervisor, the Deputy Director of the Institute of Image Communication and Network Engineering of Shanghai Jiao Tong University, the Double-Appointed Professor of the Institute of Artificial Intelligence and the Collaborative Innovation Center of Future Media Network, the Deputy Secretary-General of the China Video User Experience Alliance and head of the standards group.