This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer ...This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer of a wireless connection. Augmented with RoHC and UDP-Lite, for H.264 video transmissions over wireless channels in a heterogeneous wired-wireless environment, the erroneous packet payloads can be useful and better able to cope with lost packets (native UDP case), by adopting some of the erasure and error resilient modes in H.264. The context transfer during inter/intra handover is also discussed. Simu- lations demonstrated that the proposed scenario significantly improves the PSNR performance and video quality.展开更多
传统的基于端到端的一级视频差错保护方案大多没有考虑有线与无线混合网络的包丢失原因的差别,所以整体效率不高。为此,针对有线无线混合网络的特征,提出一种基于H.264数据分割的混合动态不均等差错保护策略。接收端可对有线和无线网络...传统的基于端到端的一级视频差错保护方案大多没有考虑有线与无线混合网络的包丢失原因的差别,所以整体效率不高。为此,针对有线无线混合网络的特征,提出一种基于H.264数据分割的混合动态不均等差错保护策略。接收端可对有线和无线网络上不同原因导致的丢包进行区分,视频服务器通过接收的RTCP(Real-Time Control Protocol)反馈,利用RS(Reed-Solomon)码和LDPC(Low Density Parity Code)码分别对抗网络中的丢包和误比特,针对H.264数据分类的重要性不同以及信道质量的变化,给予不同程度的动态保护。实验结果表明,这种两级保护混合抗误码算法与传统的基于包的端到端一级不均等差错保护相比,冗余度降低了约15%,而接收的视频质量提升了约4 dB,且很大程度地提高客户端接收的有效数据率,为解码器进行差错隐藏奠定了良好的基础。展开更多
基金Project (Nos. FP6-IST-2003-506997 and FP6-IST-2005-026943)supported partially by the European Information Society TechnologiesFramework Programme 6 Integrated Project: "Daidalos" (European ISTProject: Daidalos, 2003~2008)
文摘This paper describes how to use an Adaptive Forward Error Correction (AFEC) algorithm to efficiently protect the critical data areas of compressed headers and UDP-Lite packets for data transport in a radio link layer of a wireless connection. Augmented with RoHC and UDP-Lite, for H.264 video transmissions over wireless channels in a heterogeneous wired-wireless environment, the erroneous packet payloads can be useful and better able to cope with lost packets (native UDP case), by adopting some of the erasure and error resilient modes in H.264. The context transfer during inter/intra handover is also discussed. Simu- lations demonstrated that the proposed scenario significantly improves the PSNR performance and video quality.
基金Supported by the National Natural Science Foundation of China under Grant Nos.6047207660673178+3 种基金60434030(国家自然科学基金)the National Grand Fundamental Research973Program of China under Grant No.2006CB303007(国家重点基础研究发展规划(973))the National High-Tech Research and Development Plan of China under Grant.Nos.2006AA01Z2182006AA01Z215(国家高技术研究发展计划(863))
文摘传统的基于端到端的一级视频差错保护方案大多没有考虑有线与无线混合网络的包丢失原因的差别,所以整体效率不高。为此,针对有线无线混合网络的特征,提出一种基于H.264数据分割的混合动态不均等差错保护策略。接收端可对有线和无线网络上不同原因导致的丢包进行区分,视频服务器通过接收的RTCP(Real-Time Control Protocol)反馈,利用RS(Reed-Solomon)码和LDPC(Low Density Parity Code)码分别对抗网络中的丢包和误比特,针对H.264数据分类的重要性不同以及信道质量的变化,给予不同程度的动态保护。实验结果表明,这种两级保护混合抗误码算法与传统的基于包的端到端一级不均等差错保护相比,冗余度降低了约15%,而接收的视频质量提升了约4 dB,且很大程度地提高客户端接收的有效数据率,为解码器进行差错隐藏奠定了良好的基础。
