为增强无线多跳网络(Ad hoc网络)中视频传输的抗误码性能,提出了一种面向Ad hoc网络的视频多描述编码及其传输方法。首先,通过判断两个相邻帧运动矢量的差值,自适应地在视频序列中插入参考帧以提高帧间编码效率;然后分别抽取出视频序列中的奇数帧和偶数帧形成两个描述;最后,在确保传输路径可靠性的基础上,选取两个质量较高的节点不相交路径分别传输视频序列的两个描述,以提高视频传输的可靠性。OPNET Modeler中的仿真实验结果表明,与目前Ad hoc网络中典型的多描述编码及传输方法MDC_AODV相比,本文提出的方法有效地增强了视频传输的抗误码性,提高了接收端的视频质量。
The multiple description video coding and video transmission scheme in Ad hoc network is presented in this paper in order to improve the quality of video and enhanced error resilience of video transmission. To improve the inter-coding efficiency, one or more reference frames were added between two adjacent frames by determining the magnitude of the difference of motion vectors of adjacent frames. Then the odd frame and the even frame were extracted from the video sequence and formed two descriptions respectively. On the basis of maximum reliability of routes, two descriptions of video frequency were transmitted to two disjoint routes respectively, which can increase the robustness of video transmission. The simulation on OPNET Modeler shows that the error resilience of video transmission has been improved and the video quality has been enhanced compared with MDC_AODV.