Existing wireless video transmission schemes directly conduct video coding in pixel level, while neglecting the inner semantics contained in videos. In this paper, we propose a wireless video semantic communication framework, abbreviated as WVSC, which integrates the idea of semantic communication into wireless video transmission scenarios. WVSC first encodes original video frames as semantic frames and then conducts video coding based on such compact representations, enabling the video coding in semantic level rather than pixel level. Moreover, to further reduce the communication overhead, a reference semantic frame is introduced to substitute motion vectors of each frame in common video coding methods. At the receiver, multi-frame compensation (MFC) is proposed to produce compensated current semantic frame with a multi-frame fusion attention module. With both the reference frame transmission and MFC, the bandwidth efficiency improves with satisfying video transmission performance. Experimental results verify the performance gain of WVSC over other DL-based methods e.g. DVSC about 1 dB and traditional schemes about 2 dB in terms of PSNR.

翻译：现有的无线视频传输方案直接在像素层面进行视频编码，而忽略了视频中包含的内在语义。本文提出一种无线视频语义通信框架（简称WVSC），将语义通信思想融入无线视频传输场景。WVSC首先将原始视频帧编码为语义帧，随后基于这种紧凑表示进行视频编码，实现语义层面而非像素层面的视频编码。此外，为进一步降低通信开销，本框架引入参考语义帧以替代传统视频编码方法中每帧的运动矢量。在接收端，提出多帧补偿机制，通过多帧融合注意力模块生成补偿后的当前语义帧。借助参考帧传输与多帧补偿机制，系统在保证视频传输性能的同时显著提升了带宽效率。实验结果表明，在PSNR指标上，WVSC相较于其他基于深度学习的方法（如DVSC）提升约1 dB，较传统方案提升约2 dB。