Inter-mode decision with varied computational complexity
Jiyuan Lu, Peizhao Zhang, Hongyang Chao, Paul S. Fisher · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2010
Variable block size motion compensation significantly improves the rate-distortion performance of video coding at the cost of high computational complexity. Currently, fast inter-mode decision algorithms only improve the speed of intermode decision (MD) but do not provide a flexible computational complexity control to adapt to different hardware platforms with optimized rate-distortion (R-D) performance. Instead of speeding up inter-mode decision merely, we attempt to propose a complexity adjustable inter-mode decision algorithm to attain optimized coding performance under different computational complexity constraints herein. Our algorithm predicts the Lagrangian cost and complexity slope (J-C slope) of MD for each macroblock (MB) by exploiting their temporal and spatial correlations. MD is applied on the MBs with larger J-C slope to provide the better prediction performance with less computational cost. Adjustable complexity is obtained by preset the number of MBs on which MD is applied for each frame. According to our experiments, the algorithm can both freely adjust the computational complexity and provides an improved R-D performance under different computational constraints.