• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2016, Vol. 38 ›› Issue (02): 325-330.

• 论文 • 上一篇    下一篇

H.264码率控制跳帧算法的优化

周全1,2,3,王中元1,2,3   

  1. (1.武汉大学国家多媒体软件工程技术研究中心,湖北 武汉 430072;2.湖武汉大学计算机学院,湖北 武汉 430072;
    3.武汉大学深圳研究院,广东 深圳 518063)
  • 收稿日期:2015-01-09 修回日期:2015-04-03 出版日期:2016-02-25 发布日期:2016-02-25
  • 基金资助:

    国家自然科学基金(61271256,U1404618);湖北省重大科技创新计划(2013AAA020);粤港关键领域重点突破项目(2012A090200007)

Frame skipping strategy optimization
in H.264 rate control algorithm

ZHOU Quan1,2,3,WANG Zhongyuan1,2,3   

  1. (1.National Engineering Research Center for Multimedia Software,Wuhan University,Wuhan 430072;
    2.School  of Computer,Wuhan University,Wuhan 430072;
    3.Research Institute of Wuhan University in Shenzhen,Shenzhen  518063,China)
  • Received:2015-01-09 Revised:2015-04-03 Online:2016-02-25 Published:2016-02-25

摘要:

传统的H.264码率控制算法跳帧策略,将缓冲区占有率和图像复杂度作为判断跳帧的依据。然而,图像复杂度虽然可以反映序列的运动剧烈程度,但不能完全刻画相邻帧的时域相关性,从而影响视频编码质量。针对这一问题,首先用相对复杂度代替复杂度,从而更好地反映当前帧与前面帧的时域联系;然后提出比特因子的概念,从缓冲区、相对复杂度、比特因子三方面综合给出跳帧条件。实验结果表明,改进算法跳帧后视频的峰值信噪比PSNR有明显提高,而且视频的流畅性也得到了改善。

关键词: 视频编码, 码率控制, 跳帧, 相对复杂度, 比特因子

Abstract:

Traditional frameskipping strategies in H.264 rate control algorithm use buffer occupancy and image complexity as a criterion. Although complexity can reflect the motion, it cannot reflect the temporal relationship between the current frame and previous frames, leading to low encoding quality. To address this problem, we improve it from two aspects. First, Complexity is replaced with relative complexity, so that the temporal dependency relationship can be better characterized. Second, bit factor is introduced to establish a comprehensive frameskipping measure along with buffer occupancy and relative complexity. Experimental results show that our optimization has higher PSNR and the video behaves better in continuity.

Key words: video coding;rate control;frame skipping;relative complexity;bit factor