There is nowadays a growing demand in vehicular communications for real-time applications requiring video assistance. The new state-of-the-art high-efficiency video coding (HEVC) standard is very promising for real-time video streaming. It offers high coding efficiency, as well as dedicated low delay coding structures. Among these, the all intra (AI) coding structure guarantees minimal coding time at the expense of higher video bitrates, which therefore penalizes transmission performances. In this work, we propose an original cross-layer system in order to enhance received video quality in vehicular communications. The system is low complex and relies on a multiple description coding (MDC) approach. It is based on an adaptive mapping mechanism applied at the IEEE 802.11p standard medium access control (MAC) layer. Simulation results in a realistic vehicular environment demonstrate that for low delay video communications, the proposed method provides significant video quality improvements on the receiver side.

翻译：当前，车辆通信中对需要视频辅助的实时应用需求日益增长。新一代先进的高效视频编码(HEVC)标准在实时视频流传输方面极具前景。该标准不仅编码效率高，还支持专用的低延迟编码结构。其中，全帧内(AI)编码结构虽能保证最短编码时间，但会占用更高视频比特率，进而影响传输性能。本文提出一种新颖的跨层系统以提升车辆通信中的接收视频质量。该系统复杂度低，采用多描述编码(MDC)方法，并基于适用于IEEE 802.11p标准媒体访问控制(MAC)层的自适应映射机制。在真实车辆环境中的仿真结果表明，对于低延迟视频通信，所提方法能显著提升接收端视频质量。