A frame level fuzzy video rate controller for variable bit rate applications of HEVC

摘要

Variable bit rate encoded video bit streams are suitable for a wide range of high delay applications such as video streaming applications. In these applications, the visual quality of encoded video and the buffering constraint are concerned during encoding at the same time. In this paper, a fuzzy video rate controller for variable bit rate applications of the new high efficiency video coding (HEVC) standard is proposed. The proposed controller considers a given buffer size and a long-term target bit rate as controlling constraints. It provides a variable bit rate video bit stream by controlling the quantization parameter (QP) at frame-level. The bitrate of each frame is controlled by a fuzzy controller to minimize the fluctuations of QP and PSNR that leads to high visual quality. The proposed algorithm is implemented on the HEVC standard reference software (HM) and experimental results show that it can provide an average quality, in terms of PSNR, similar to the HM rate controller and constant QP case while the buffer constraint is completely obeyed. Also in comparison with the HM rate controller, the fluctuation of QP and PSNR are less in the proposed algorithm that means a higher visual quality.