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Bit Allocation Algorithm for Joint Spatial-Temporal Scalabilities in H.264 SVC

PANG Yan, LIU Jiaying, GAO Liangcai, GUO Zongming   

  1. Institute of Computer Science and Technology, Peking University, Beijing 100871;
  • Received:2012-09-13 Online:2013-09-20 Published:2013-09-20

面向H.264 SVC空域-时域可伸缩编码的码率分配算法

庞燕,刘家瑛,高良才,郭宗明   

  1. 北京大学计算机科学技术研究所, 北京 100871;

Abstract: A bit allocation algorithm on joint spatial-temporal (S-T) scalabilities layers is proposed for H.264 SVC. Taking account of the characteristic of SVC encoding procedure, a two-step model-based bit allocation scheme is developed. Along spatial/temporal scalability dimension in each step, the bit allocation issue is formulated as an optimization problem. Then, the rate and distortion (R-D) models for dependent spatial and temporal layers are derived separately, where the complicated inter-layer dependencies are sufficiently considered. Finally, using the Lagrange multiplier method, the proposed algorithm can be solved numerically with derived R-D models. Experimental results show that the new R-D models result in a highly efficient bit allocation scheme, which outperforms the JSVM benchmark by a significant margin, and the average coding gain achieves 1.22 dB.

Key words: H.264 SVC, layers dependency, rate-distortion models, spatial-temporal bit allocation

摘要: 提出一种面向H.264 SVC空域?时域可伸缩编码的码率分配算法。通过对SVC编码过程的分析, 设计了一个两阶段基于模型的码率分配算法框架。在每一阶段中沿空域或时域可伸缩性方向上, 码率分配问题都被描述为一个优化问题进行求解。在充分挖掘层次间相关性的基础上, 提出空域、时域视频层的失真和码率模型。利用所得到的率失真模型, 使用拉格朗日乘数法, 求取该分配问题的最优数值解。实验结果表明, 新的率失真模型所提供的高效码率分配算法, 大幅度提高了现有参考代码JSVM的性能, 其编码效率平均增益达1.22 dB。

关键词: H.264SVC, 层次间相关性, 率失真模型, 空域?时域码率分配

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