《计算机应用》唯一官方网站 ›› 2022, Vol. 42 ›› Issue (3): 946-952.DOI: 10.11772/j.issn.1001-9081.2021030398

• 多媒体计算与计算机仿真 • 上一篇    

基于率失真特性的视频编码优化算法

郭红伟1,2, 樊香所3,4(), 刘帅1, 韦相1, 赵伶俐1   

  1. 1.红河学院 工学院, 云南 蒙自 661100
    2.电子科技大学 信息与通信工程学院, 成都 611731
    3.广西科技大学 电气与信息工程学院, 广西 柳州 545006
    4.电子科技大学 资源与环境学院, 成都 611731
  • 收稿日期:2021-03-16 修回日期:2021-06-28 接受日期:2021-06-30 发布日期:2022-04-09 出版日期:2022-03-10
  • 通讯作者: 樊香所
  • 作者简介:郭红伟(1980—),男(彝族),云南金平人,教授,博士,CCF高级会员,主要研究方向:多媒体通信、视频图像处理
    刘帅(1979—),男,云南宣威人,教授,博士,主要研究方向:视频图像处理
    韦相(1980—),男(壮族),广西百色人,副教授,博士,主要研究方向:视频图像处理、复杂网络
    赵伶俐(1979—),女,湖南衡阳人,教授,博士,主要研究方向:视频图像处理。
  • 基金资助:
    国家自然科学基金资助项目(62061015)

Video coding optimization algorithm based on rate-distortion characteristic

Hongwei GUO1,2, Xiangsuo FAN3,4(), Shuai LIU1, Xiang WEI1, Lingli ZHAO1   

  1. 1.School of Engineering,Honghe University,Mengzi Yunnan 661100,China
    2.School of Information and Communication Engineering,University of Electronic Science and Technology of China,Chengdu Sichuan 611731,China
    3.School of Electrical and Information Engineering,Guangxi University of Science and Technology,Liuzhou Guangxi 545006,China
    4.School of Resources and Environment,University of Electronic Science and Technology of China,Chengdu Sichuan 611731,China
  • Received:2021-03-16 Revised:2021-06-28 Accepted:2021-06-30 Online:2022-04-09 Published:2022-03-10
  • Contact: Xiangsuo FAN
  • About author:GUO Hongwei, born in 1980, Ph. D., professor. His research interests include multimedia communication, video image processing.
    LIU Shuai, born in 1979, Ph. D., professor. His research interests include video image processing.
    WEI Xiang, born in 1980, Ph. D., associate professor. His research interests include video image processing, complex network.
    ZHAO Lingli, born in 1979, Ph. D., professor. Her research interests include video image processing.
  • Supported by:
    National Natural Science Foundation of China(62061015)

摘要:

率失真(R-D)优化是视频编码器中一项关键技术,然而当前广泛采用的独立率失真优化远未达到全局最优性能。为了进一步提升高效视频编码(HEVC)的压缩性能,提出了一种结合率失真依赖性和率失真特性的二次编码优化算法。首先,采用原始HEVC的方法对当前帧进行第一次编码,从而得到当前帧消耗的比特数和每个编码树(CTU)单元的率失真模型参数;然后,结合时域依赖率失真优化,根据当前帧比特预算和率失真模型参数计算每个CTU的最佳拉格朗日乘子及量化参数;最后,对当前帧中每个CTU采用不同的优化目标重新编码。实验结果表明,在低延迟B帧和P帧编码配置下,与HEVC基准相比,所提视频编码优化算法在同样编码质量下节省了3.5%和3.8%的码率,获得了显著的率失真性能提升。

关键词: 高效视频编码, 二次编码, 率失真优化, 率失真模型, 自适应拉格朗日乘子

Abstract:

Rate-Distortion (R-D) optimization is a crucial technique in video encoders. However, the widely used independent R-D optimization is far from being global optimal. In order to further improve the compression performance of High Efficiency Video Coding (HEVC), a two-pass encoding algorithm combined with both R-D dependency and R-D characteristic was proposed. Firstly, the current frame was encoded with the original method in HEVC, and the number of bits consumed by the current frame and the R-D model parameters of each Coding Tree Unit (CTU) were obtained. Then, combined with time domain dependent rate distortion optimization, the optimal Lagrange multiplier and quantization parameter for each CTU were determined according to the information including current frame bit budget and R-D model parameters. Finally, the current frame was re-encoded, where each CTU had different optimization goal according to its Lagrange multiplier. Experimental results show that the proposed algorithm achieves significant rate-distortion performance improvement. Specifically, the proposed algorithm saves 3.5% and 3.8% bitrate at the same coding quality, compared with the original HEVC encoder, under the coding configurations of low-delay B and P frames.

Key words: High Efficiency Video Coding (HEVC), two-pass encoding, rate-distortion optimization, rate-distortion model, adaptive Lagrange multiplier

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