An enhanced two-stage multiple description video coder with drift reduction
An enhanced two-stage multiple description video coder with drift reduction
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DOI：
10.1109/tcsvt.2003.819182
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发表时间：
2004
影响因子：
8.4
通讯作者：
Yen-Chi Lee;Y. Altunbasak;R. Mersereau
中科院分区：
文献类型：
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作者：
Yen-Chi Lee;Y. Altunbasak;R. Mersereau
多重描述编码 (MDC) 是一种源编码技术，它利用路径分集来提高在易错信道上传输压缩信号的鲁棒性。然而，MDC在视频编码中的应用仍然存在问题，因为当一个描述丢失时，解码器处可能会出现称为漂移的预测失配问题。文献表明，通过对这种预测失配进行编码并将其作为三预测循环结构中的辅助信息发送，可以有效防止漂移。然而，当接收到两个描述时，该辅助信息是完全多余的。基于 A. Reibman 等人的三预测循环结构，我们在中央预测循环中提出了一种非常简单但高效的两级 MDC。 （参见 Proc. IEEE Int. Conf. 图像处理 - ICIP'99, p.837-41, 1999）。我们在中央预测循环中引入了一个额外的多描述标量量化器。辅助信息的编码被修改为可以在不发生漂移时用于提高视频质量，但仍然保持漂移防止能力。不同视频序列在不同丢包率下的仿真结果表明，所提出的两级 MDC 结构确实提高了通道无差错时的质量，同时有效避免了一种描述完全丢失时的漂移。
Multiple description coding (MDC) is a source coding technique that exploits path diversity to increase the robustness of transmitting a compressed signal over error-prone channels. However, the application of MDC to video coding is still problematic because a prediction mismatch problem, called drift, may occur at the decoder when one description is lost. In the literature, it has been shown that drift can be effectively prevented by encoding this prediction mismatch and sending it as side information in a three-prediction-loop structure. However, this side information is totally redundant when both descriptions are received. We propose a very simple, but efficient two-stage MDC in the central prediction loop based on the three-prediction-loop structure of A. Reibman et al. (see Proc. IEEE Int. Conf. Image Processing - ICIP'99, p.837-41, 1999). We introduce an additional multiple description scalar quantizer into the central prediction loop. The encoding of the side information is modified in such a way that it can be used to improve the video quality when no drift occurs, but still maintain a drift prevention capability. The simulation results, with different video sequences at various packet loss rates, demonstrate that the proposed two-stage MDC structure indeed enhances the quality when the channel is error-free, yet effectively avoids drift when one description is completely lost.