计算机与现代化

• 算法分析与设计 •    下一篇

HEVC熵编码算法优化

徐 飞1,张永飞1,2,李 哲1   

  1. 1.北京航空航天大学计算机学院数字媒体北京市重点实验室,北京100191;
    2.北京航空航天大学虚拟现实技术与系统国家重点实验室,北京100191
  • 收稿日期:2013-09-12 修回日期:1900-01-01 出版日期:2013-12-18 发布日期:2013-12-18

Optimization Algorithm of HEVC Entropy Coding

XU Fei1, ZHANG Yong-fei1,2, LI Zhe1   

  1. 1. Beijing Key Laboratory of Digital Media, School of Computer Science and Engineering, Beihang University, Beijing 100191, China;
    2. State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, Beijing 100191, China
  • Received:2013-09-12 Revised:1900-01-01 Online:2013-12-18 Published:2013-12-18

摘要: 新一代视频编码标准HEVC提供了更加灵活的编码工具选择,在提高压缩率的同时也提高了编码的计算复杂度。由于可选择更大的变换单元以及编码中更强的系数间依赖关系,在率失真优化(RDO)模式选择过程中,HEVC熵编码的计算复杂度显著高于H.264/AVC。为了解决这一问题,本文对HEVC熵编码算法进行优化,通过优化熵编码的上下文空间选择过程、非零系数的编码结构,以及对不同大小的变换矩阵进行整体优化。实验结果表明,本文提出的优化算法能够在保证视频编码质量基本不变的同时,平均降低约43%的熵编码时间。

关键词: 视频编码, HEVC, 熵编码

Abstract: The latest video compression standard HEVC adopts more flexible compression tools to reach a higher compression rate compared to its predecessor H.264/AVC, meanwhile the computation of HEVC is more complicated. Mainly because the larger Transform Unit and the stronger dependence between transform coefficient, entropy coding of HEVC in RDO (Rate-Distortion Optimization) is much more complex than that in H.264/AVC. This paper proposed several techniques to optimize the entropy coding process of HEVC, including context selection optimization, significant coefficient coding optimization and different size coefficient block optimization. Experiment results show that the proposed schemes can reduce on average 43% of the entropy coding time in RDO without losing compression performance.

Key words: video compression, HEVC, entropy coding