Joint algorithm-architecture optimization of CABAC to increase speed and reduce area cost

To address the increasing demand for higher resolution and frame rates, processing speed (i.e. performance) and area cost need to be considered in the development of next generation video coding. Accordingly, both algorithm and architecture should be taken into account during video codec design. This paper proposes joint optimization of both the algorithm and architecture to ensure that high coding efficiency can be achieved in conjunction with high processing speed and low area cost. Specifically, it presents two optimizations that can be performed on Context-based Adaptive Binary Arithmetic Coding (CABAC), a form of entropy coding in H.264/AVC. First, subinterval reordering is proposed for the arithmetic de coder to increase the processing speed by 14 to 22% with no cost to coding efficiency. Second, modification of the motion vector difference (mvd) context selection is proposed to reduce memory requirements (i.e. area cost) by 50% with negligible coding efficiency impact (≤0.02%). These joint algorithm and architecture optimizations are non-standard com pliant and thus are well suited to be used in High Efficiency Video Coding (HEVC), the successor to H.264/AVC.