Fast Mode Decision with Adjustable Computational-complexity for H.264/AVC Encoder

H.264/AVC video coding standard employs multiple coding-modes and significantly improves coding efficiency at the cost of heavy computational load.To reduce the computation burden,a fast mode decision algorithm with adjustable computational-complexity is presented.According to the analysis of the characteristics of the coding-modes and statistical characteristics about the best mode,the proposed algorithm exploits motion activity and the quantized transform coefficients of the residue obtained by the tested coding-modes,to effectively predict the coding efficiency of the remaining modes and skip the unnecessary modes,further more thresholds used in this algorithm can be adjusted to regulate computational complexity.Experimental results show that the speed of the proposed method is about 2~4 times faster than the full-mode decision algorithm without any noticeable loss of image quality and coding efficiency.