The dissemination of video information contents migth enhance the performances of safety-related applications in vehicular ah-hoc networks (VANETs). A major problem concerns the high sensitivity of the compressed video streams to the severe channel conditions in wireless ad-hoc networks. The reliable dissemination of video contents in mobile environments is recognized as one of the main challenges for the developing and deploying of VANETs. To improve the robustness of dissemination, we propose RCP+ (Road-Casting Protocol) scheme for distributing high-definition video contents in VANETs. RCP+ is a cross layer dissemination mechanism for video safety messages that specifically addresses highway scenarios with zero infrastructure support. Also, a comparison of one of the most popular and widely spread video encoder H.264/AVC with respect to the recently released video coding scheme H.265/HEVC is presented. The comparison is performed by means of simulations showing differences between encoding algorithms in terms of perceived quality. The results indicate a better performance of HEVC based encoding algorithm in comparison to AVC in VANET environments.