This paper proposes a fast mode decision algorithm for H.264/AVC based on skip prediction and early termination techniques. The skip decision is based on a partially computed Sum of Absolute Differences metric combined with utilization of the Lagrangian Rate- Distortion cost function from the previous frame. A statistical analysis of the spatio-temporal characteristics of the Rate Distortion cost function and SAD metric for skip decisions is provided. Experimental results show that the new algorithm outperforms existing ones in performance providing a 55% reduction in total computational complexity, a slight reduction in bit rate and negligible impact on visual quality.
