Most existing wireless network coding mechanisms do not consider the impact of wireless link quality on video transmission, resulting in the degradation in video quality. To address the above issue, this paper proposes an Optimized Opportunistic Network Coding (O2NC) mechanism, in combination with opportunistic routing, for video transmission in wireless networks. The candidate relay set is computed according to the transmission path gain and the importance of video data. Meanwhile, the comprehensive utility of a coded packet is estimated by considering the parameters of coding ratio and the priority of video data. On this basis, the coded packet with the largest utility is chosen for transmission. Simulation results demonstrate that, compared with typical network coding protocols, O2NC achieves significant performance improvement in terms of decodable frame ratio and average Peak Signal to Noise Ratio (PSNR) of video clips.%现有的无线网络编码机制大多没有考虑无线链路质量对于视频传输的影响，导致视频质量降低。该文针对这一问题，提出面向视频传输优化的机会网络编码(O2NC)机制。该机制结合网络编码和机会路由技术，根据传输路径收益和视频数据的重要程度计算候选节点集合；同时，考虑视频数据包编码比重和重要程度等参数，评估编码包综合效用，选取转发效用值最大的视频编码组合。仿真结果表明，与典型的网络编码协议相比，O2NC机制能够显著提高视频序列的可解码帧率和峰值信噪比(PSNR)。
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