**6. Conclusions**

In order to develop the low-complexity and hardware-friendly H.265/HEVC encoder for VANETs, based on a novel spatiotemporal neighborhood set, the Bayesian rule and Gibbs Random Field are used to reduce the encoding complexity for the H.265/HEVC inter-prediction in this work. The proposed algorithm consists of CTU depth decision and PU mode decision methods. Experimental results demonstrate that the proposed approach can reduce the average encoding complexity of H.265/HEVC encoder by about 50% for VANETs, while the increasing of BDBR is less than or equal to 0.8% on average.

**Author Contributions:** X.J. designed the algorithm, conducted all experiments, analyzed the results, and wrote the manuscript. J.F. analyzed the results. T.S. conceived the algorithm. T.K. conducted all experiments.

**Funding:** This work was supported by in part of by the National Natural Science Foundation of China under grant 61701297, in part of by the China Postdoctoral Science Foundation under grant 2018M641982, in part of by the China Scholarship Council and Mitacs, in part of by JSPS KAKENHI under grant 17K00157, and in part of by the Shanghai Sailing Program under grant 1419100.

**Conflicts of Interest:** The authors declare no conflict of interest.
