Research On Rate Control For Surveillance Video Coding Based On HEVC

Due to the wide deployment of surveillance cameras, surveillance videos are explosively increasing every day and night. The key challenge is how to effectively store and transmit such huge amounts of surveillance video data. Since the scene was relatively stable after fixed surveillance camera were installed, background based surveillance video coding methods had remarkably improved surveillance video compressing performance, which encoded the modeled background frame into the bit stream with smaller QP values to achieve a better prediction reference. However, the high-quality reconstructed background frames may lead to bursting bit-rate peaks in the video transmission, which may cause the buffer overflow. Therefore, the paper focuses on the rate control problem of the surveillance video coding, and proposes a quality-progressive coding method to address the burst peaks of background frames problem. Also, combining the rate control technique in HEVC, a rate control method for surveillance videos is proposed to handle the surveillance video transmission problem with limited bandwidth. Moreover, a surveillance video dataset for coding performance evaluation, PKU-SVD-A, is proposed in this paper.This paper focuses on the following points:Firstly, to address the problem of the bursting bit-rate peaks of background frames, the paper puts forwards a quality-progressive coding method for background frames. Instead of a single high-quality reconstructed background frame, this method divide the background frame into a basic reconstructed background frame of normal-quality and a series of reconstructed residual frames, for respective transmission. Meanwhile, coding bits of these frames are less than those of I frame. The experimental results show that, when a modeled background frame comes, this method can eliminate the transmission pressure as well as the potential buffer overflow, and will not decrease the compressing performance.Secondly, for the surveillance video transmission problem with limited bandwidth, combining the rate control method in HEVC and the quality-progressive coding method, this paper proposes a rate control method for surveillance video coding. According to the target bit rate, the proposed method adopts the model and quality-progressive coding of background frames to realize the rate control of the entire stream. The experimental results show that the proposed method achieves the effective rate control but also keeps the advantage of background based video coding.Thirdly, for the lack of surveillance video data set, a raw surveillance video data set PKU-SVD-A is constructed. The dataset is divided into different levels considering the aspects of weather, illumination, extreme case and so on. In addition, the minimum length of surveillance video sequences is reported according to the experimental results.In short, this paper proposes a quality-progressive coding method for background frames in HEVC-S which solves the bursting bit-rate peaks of background frames and keeps the coding performance. After that, a rate control method is put forward which avoids the drawback of HEVC-S in rate control. At last, the paper provides an evaluation dataset for surveillance video coding.