Rate Control Algorithm Research And Optimization In HEVC

"With the development of technology and people’s increasing demands of high-quality video, high-definition, ultra-high definition video has been more widely used. For more effective compression video coding of large size videos, Moving Pictures Experts Group (MPEG) of ISO/IEC and "Video Coding Experts Group (VCEG) jointly launched a next-generation video codec standard project, which is called HEVC (High Efficiency Video Coding), based on the H.264/AVC. Compared with the H.264/AVC video coding standard, the HEVC standard is expected to have50percent performance improvement, with the same video quality.HEVC standard adopts many new coding techniques, with higher complexity, more difficult in rate control. Meanwhile there’s no specification in the rate control scheme of HEVC, thus allows various research institutions or firms develop their own algorithm according to their needs.There is much room for improvement in the existing bit allocation scheme and rate control, which did not make use of the latest techniques introduced by HEVC. This paper makes a deep research in the rate control algorithm of HEVC, proposed a logarithmic rate-quantization (R-Q) model based rate control scheme, with hierarchical bit allocation.According to the statistic of video sequence, the output bitrate of coded sequences R and quantization step Q meet logarithmic relationship. Meanwhile this paper adopts a top-down hierarchical bit allocation scheme, including image complexity analysis, GOP level, Frame level, and Coding Unit level bit allocation. Experimental results show that the proposed rate control algorithm has a higher accuracy, and has smaller video coding distortion.