Fast encoding of surveillance videos based on HEVC
An increasing number of deployed surveillance cameras raise a huge demand for higher efficiency video coding scheme, and the emerging background reference based video coding methods with High Efficiency Video Coding (HEVC) have achieved a large increase of coding efficiency on surveillance videos. However, the high encoding complexity of HEVC causes troubles for these methods to be adopted in practice, especially in real-time coding scenarios. Among all the factors resulting in the increase of encoding complexity, mode decision and motion estimation are both critical reasons. Therefore, a fast algorithm based on a block-level background generation method is proposed to address this problem for surveillance video. With the help of fast detection of background coding units, the Merge mode is early decided, some prediction modes at specific depths that have the least probabilities are skipped using early termination during rate-distortion optimization, and unnecessary motion estimation is also avoided. Thanks to the full utilization of the static camera premise, the proposed fast algorithm achieves 77.0% reduction of encoding time, while only incurs 1.0% performance loss that is negligible. More experimental results also verify that the proposed algorithm outperforms the state-of-the-art schemes.