对具有帧间相关性的分层视频码流的非均匀错误保护

UNEQUAL ERROR PROTECTION FOR SCALABLE VIDEO WITH INTER-FRAMEDEPENDENCIES

在分层视频码流的网络实时传输中,非均匀错误保护(UEP)技术已经被广泛地研究。至今为止,几乎所有的UEP相关工作都是针对具有链式结构的单一码流。但是,在一些实际的图像及视频编码系统(例如MPEG-4)产生的码流中,都存在着更为复杂的树型相关性结构。针对这种具有树型相关性结构的码流提出了一种打包方案,并在此基础上提供了两种带宽分配方案。试验中,采用MPEG-4FGS作为信源编码器。试验结果表明,采用灵活的帧间自适应带宽分配方案可以有效地提高系统性能。

Unequal error protection（UEP） for transmitting scalable image and video bitstreams over packet erasure networks has been extensively studied. Most of the existing works consider UEP for a single source bitstream with chain-structure dependencies. However, in some state-of-the-art image and video coding techniques, such as MPEG -4 fine-grained scalable （FGS）, there exists more complex tree-structure dependencies. In this paper, we propose a packetization framework for tree-structured bitstream, and present two rate allocation algorithms. Using MPEG -4 FGS as the source encoder,our experimental results show that the performance in terms of mean PSNR can be improved by adaptively allocating available bandwidth to different frames.