码率约束抗丢包伸缩码流保护的码率分配方法

针对现有传输码率约束抗丢包不等保护系统的码率分配方法不能兼顾复杂度和性能的缺陷，提出了一种基于估计的码率分配新方法．先给出了系统失真优化解的期望失真的上下界，由于该上下界仅与等保护方案有关，因此可以快速确定．然后，利用上下界估计最优的交织器参数，从而避开了求解每一候选交织器参数对应的失真优化解所带来的耗时大的问题．采用双状态马尔可夫网络模型，通过对可伸缩图像／视频码流数据进行实验，结果表明，新方法能够获得近似最优的系统性能，具有复杂度低和鲁棒性强的优点．

Code-Rate Allocation Method of Unequal Loss Protection for Scalable Bitstreams with Rate Constrain

Focusing on the flaw that the complexity is incompatible with performance in the existing code-rate allocation methods of the unequal loss protection system with transmission rate constraint, a new code-rate allocation method based on estimation is proposed. Firstly, the upper and lower bounds on the expected distortion of a distortion-based optimal solution for this system are given, which depend only on an equal loss protection scheme and accordingly can be determined easily, and then the optimal interleaver parameters are estimated from the above upper and lower bounds so as to avoid the time consuming caused by computing the distortion-based optimal solution for each candidate interleaver parameters. Experiments are carried out by using the twostate Markov network model for scalable image and video coders. The results show that the new method can provide near optimal system performance, and has both advantages of low complexity and high robustness.