3G对话式视频业务中H．264／AVC的容错策略

3G通信技术的出现使对话式无线视频业务成为可能，而且最新的3GPP／3GPP2标准要求3G终端支持H．264／AVC视频编解码技术，但由于无线网络传输的误率高，因此必须为3G对话式视频业务提供相关的容错技术；同时由于硬件的限制，3G终端只支持部分H．264／AVC的容错工具。针对上述问题，根据3GPP／3GPP2标准，在对H．264／AVC中的各种容错工具在基于分组交换的3G对话式视频业务中的适用性进行分析的基础上，给出了一些实用性的容错方案。这些容错方案的性能经过一般测试条件测试，实验结果表明，能够得到比较满意的纠错效果。同时通过对各种实验数据的分析可见，在这种低带宽、高误码率的环境中，若编码时采用复杂度低的FMO方式，再辅以合适的帧内编码块刷新模式，则可以充分利用帧内宏块的空间相关性，以便在有限的带宽内能得到更好的纠错能力。

H. 264/AVC Error Resilience Strategies for 3G Conversational Video Services

The third generation mobile system(3G) makes mobile conversational video transmission in wireless environment possible and H.264/AVC is optionally supported by the latest 3GPP/3GPP2 standards.Error resilience protection for 3G video stream is necessary due to high packet loss rate in wireless environment.Moreover,3G mobile terminals support only part of error resilience tools of H.264/AVC because of the hardware restrictions.This paper presents various error resilience tools and their usability in 3G environment,at the same time,some simple error resilience schemes for packet-switched 3G conversational services are proposed.Performances of these strategies are tested using off-line common test conditions.Experimental show that these strategies can obtain reasonably satisfactory error correction ability.Experiments data also show that,encoder with low complexity FMO method and appropriate intra block refreshing can get better error correction ability,because this method can make full use of spatial correlation between frames and reduce the requirement of bit rate.