可伸缩码流抗丢包保护的交织器参数选择方法

给出了丢包不等保护(ULP)失真优化解的期望失真的上下界,该上下界仅与率优化解和丢包等保护(ELP)失真优化解有关。利用此上下界,提出了基于估计的选取最优交织器参数的新方法。该方法在搜索最优交织器参数时,通过ULP失真优化解的期望失真的上下界估计其期望失真,避开了多次求解ULP失真优化解的步骤,加快了搜索速度。采用双状态马尔可夫网络模型,对SPIHT和3D SPIHT编码器产生的码流数据进行仿真实验,结果表明,与原有方法相比较,新方法兼有速度快和估计精度高的特点。

Optimal Parameters Selection of Interleaver for the Unequal Loss Protection of Scalable Bitstreams

In this paper,the upper and lower bounds on the expected distortion of an ULP distortion-based solution are given,which depends only on a rate-based solution and an ELP distortion-based solution.Then a new algorithm based on estimation is presented for the selection of the optimal interleaver parameters.Instead of computing each ULP distortion-based solution for each possible choice of interleaver parameters,it estimates the expected distortion of each ULP distortion-based solution from its upper and lower bounds,which results in the speedup of the search process for the optimal interleaver parameters.Experiments are carried out with the source coders of SPIHT and 3D SPIHT by using the network model of two-state Markov.The results show that the new algorithm is characterized by higher estimation precision with similar computational complexity as compared to the previous algorithm.