Window-level rate control for smooth picture quality and smooth buffer occupancy

Traditionally, rate control consists of bit allocation and QP decision on R-QP model. In bit allocation, target bits is fur-ther confined if buffer overflows. Meanwhile, rate control should also give as smooth as possible picture quality. How-ever, there is no explicit relationship between picture qual-ity and encoding parameters, so the coding result on picture quality is usually unpredictable and uncontrollable. On the condition of smooth picture quality, the smooth buffer occu-pancy is preferable certainly. In our work, we first proposed a “window model”formulating the size of window and varia-tions of picture quality and buffer occupancy. Thus, given the constraint on picture quality and buffer occupancy, the com-pliant coding result about them can be expected employing window model. Second, a window-level rate distortion (R-D) model inspired by the traditional ρ-domain model is in-troduced. Lastly, the evaluation of our proposal is presented with elaborate experiments