中文摘要：

基于中粒度质量可伸缩（medium grain scalable，MGS）编码在可伸缩编码（scalable video coding，SVC）应用中的广泛性，在分析了MGS编码结构特点和问题的基础上，利用DCT系数分布特性提出MGS片层数据重要性的估计方法实现对MGS编码各片层重要性的估计。在此重要性估计方法的前提基础上，将之应用于指导可伸缩编码中的码流提取和容错编码。实验测试结果表明，MGS片层数据重要性估计方法的准确性和应用有效性，保障了视频码流质量，提高了码流提取效率。

英文摘要：

MGS is widely applied in SVC. Based on analyzing the MGS coding mechanism, existed problems and characteristics of integer transform coefficients distribution, this paper proposed a method to evaluate the sensitivity of MGS slice and applied the proposed method to the application of bit-stream extraction and error resilient. Experiments show the accuracy and effective of MGS slice sensitivity evaluation. And the methods of bit-stream extraction and error resilient based on MGS slice sensitivity evaluation have better performance compared to the conventional methods of SVC.