I. Introduction
The rapid development and evolution of multimedia and network technologies have stimulated the explosion of various video services such as videophone, mobile video, surveillance, digital camera, TV broadcasting and so on. And recently there has been an increasing trend of using HD or even ultra HD videos in practical applications, where videos involve plenty of useful information and corresponding coding technologies become critical for effective storage or transmission. In order to further compress abundant data and accommodate various services with different resolutions, scenarios, and terminals, the new generation video standard of H.265/HEVC [1] is formulated aiming at higher performance, where various advanced tools are incorporated for further improving the coding efficiency. So the H.265/HEVC is gradually gaining a wide interest in research and industrial, such as fast coding algorithms [2], [3], efficiency improvement algorithms [4] and so on.