混合视频编码控制中一种新的自适应Lagrange乘数选取模型

周树民; 李锦涛; 黄  晁; 宋  磊

混合视频编码控制中一种新的自适应Lagrange乘数选取模型

1(中国科学院计算技术研究所数字化研究室北京 100080) 2(中国科学院研究生院北京 100080) (smzhou@ict.ac.cn)

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出版历程
- 发布日期: 2005-11-14

A New Adaptive Lagrange Multiplier Selection Model in Hybrid Video Coder Control

1(Digital Technology Laboratory, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080) 2(Graduate University, Chinese Academy of Sciences, Beijing 100080)

摘要

摘要: 目前广为采用的Lagrange乘数选取模型λ=cQ2(平方模型SM)是在基于乘数λ为独立于失真D和比特率R的常数这一假定而得出的.但实际上根据实验观察和理论分析可知，相对于D和R乘数λ不能看做是独立的常数.基于这一命题，从理论推理的角度提出了新的乘数模型(二次函数-对数模型QLM).该模型相对于平方模型，理论上更为合理，而且实验分析也表明，采用该模型后R-D性能得到了提高(平均提高0.03dB)，从而证明了所提模型的合理性.
- Lagrange乘数选择 /
- R-D优化 /
- 视频编码
Abstract: The equation λ=cQ2 has been widely used as a parameter selection model in hybrid video coder control with Lagrange rate-distortion optimization, which is called square model (SM) and deduced with an assumption of λ being constant. The coefficient c is obtained from statistic in different video coding recommendations. However, according to the theoretical analysis, λ shouldn't be seen as a constant. A proposition about this idea is proposed and proved by mathematically deducing and experimental justification. Based on the proposition, a new Lagrange multiplier selection model called quadratic-logarithm model (QLM) is deduced and its parameter is adaptively obtained by the scheme proposed in the paper. Finally, QLM is used in H.264 and a new rate-distortion scheme is proposed. The final simulation result shows that compared with SM, the new multiplier selection model can obtain better rate-distortion performance in general sense (0.03dB ave.) without any further extra computation. Therefore, the multiplier model proposed is more feasible and reasonable than the existing ones.
- Lagrange multiplier selection /
- rate-distortion optimization /
- hybrid video coder