新一代视频编码标准HEVC变换方法的研究

高性能视频编码( HEVC)将成为国际最新的视频编解码标准.该标准主要针对目前应用日益广泛的高清甚至超高清视频而开发,其编码的性能目标是在保持原来H.264/AVC的视频质量的同时,将比特率再降低一半.与原有标准一样,HEVC对帧内或帧间的残差信号进行正交变换以集中能量至矩阵左上角,然而H.264/AVC标准中的传统DCT方法对于高清视频的处理已不能有较好效果.讨论研究目前针对HEVC正交变换提出的变换方法,包括基于模式的方向变换MDDT、自适应离散余弦/正弦变换(DCT/DST)、旋转变换(ROT)、IDCT修剪和变换跳过模式(TSM)等方法.实验结果显示了上述几种方法在比特率降低、编码时间缩短、软硬件实现复杂度降低和客观视频质量等方面的改进.最后,提出了对HEVC正交变换的进一步研究方向.

Rate-control Algorithm of H.264/AVC Based Human Visual System

HEVC will be the newest international video coding standard.Its goal is to achieve 50% bitrates deceasing than H.264/AVC and keeping the same video quality at the same time.Similar to the H.264/AVC standard,the residual signals is transformed to focus the energy.However,the transform methods of H.264/AVC can not perform well for higher resolution videos.In this paper,several novel orthogonal transform methods,including Mode-Dependent Directional Transform(MDDT),adaptive DCT/DST selection,Rotational Transform(ROT),IDCT pruning and Transform skip mode,are studied.The simulation result shows that these methods outperforms the existing methods in one of the norms,including bitrates saving,encoding time saving,computation complexity and objective video pictures quality.Finally,the future research direction is proposed on orthogonal transform for the emerging HEVC video coding standard.