在Wyner-Ziv视频编码传输系统中,关键帧的正确传输和准确解码对于整个系统的编解码性能有着重要影响.然而在无线通信系统中,由于网络故障、网络拥塞等会造成关键帧数据丢包的问题,这严重影响了接收端的解码质量.本文针对关键帧丢包问题提出一种新的解决方案,即在有反馈信道的条件下,通过对丢包帧增加部分额外Wyner-Ziv码流进行纠错并恢复解码端的受损图像,从而有效地提升视频质量.实验测试结果表明:当关键帧丢包率为1%~20%时,相比于典型的帧内错误隐藏算法,本文方案对重建图像纠错后的PSNR最大可提高20dB,且即便是丢包率很高的情况下,也能够较好地提升关键帧的R-D性能.
In Wyner-Ziv video coding system, correct transimission and accurate decoding of key frames would affect the whole system performance directly. However, in wireless communication system, data loss of key frames often happened due to network failure, network congestion or other reasons. Data lossy seriously affect the decoding quality. This paper presents a novel solution for the data loss of key frames under the conditions of feedback channel. In the solution, by sending some extra Wyner-Ziv code streams along with the origin key frames, errors of the damaged image at the decoder can be high-efficiently corrected and restored. Simulation results show that the proposed solution could reconstruct the damaged image effectively, and the quality could be improved up to 20dB compared with typical error concealment method when the data loss ratio is 1%-20%. Furthermore, R-D performance of key frames could be improved even if the data loss ratio is very high.