CNN Accelerated Intra Video Coding, Where Is the Upper Bound?


The very high complexity of the High Efficiency Video Coding standard (HEVC) is the main hurdle for its wide deployment and use. To tackle this problem, a number of recent research outcomes exploit Convolutional Neural Network (CNN) in each HEVC module for reducing the coding complexity. In this paper an effective method to analyse the potential of CNN techniques to reduce the computational cost of HEVC is proposed. A theoretical upper bound for the effectiveness of this approach in common HEVC modules is investigated. The theoretical maximum of learning-based complexity reduction in HEVC and possible reasons for Rate-Distortion (RD) loss are investigated. On the basis of this analysis, an Intra Video Coding Acceleration (IVCA) scheme is proposed, where Border Considered CNN (BC-CNN) based Coding Unit (CU) partition and heuristic Prediction Unit (PU) partition are seamlessly integrated. According to the experimental results, 66.7% of intra coding time can be saved with negligible 1.71% Bjøntegaard delta bit-rate (BDBR) loss. These results partially demonstrate the superiority of the proposed technique against other state-of-the-art approaches aiming at reducing HEVC complexity in intra mode.

2019 Picture Coding Symposium (PCS)
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.