Fast Intra 4×4 mode elimination approaches for H.264

Abstract

This paper presents two fast Intra 4×4 mode elimination approaches for H.264. They terminate at an early stage during the Intra 4×4 mode decision process. The lossless approach checks cost after each 4×4 block Intra mode decision, and jumps directly to Intra 16×16 mode decision if the cost is higher than minimum cost of Inter mode. The lossy approach shortens Intra 4×4 mode decision process by using some low-cost preprocessing to make prediction, and checking if the cost is higher than some fraction of min cost of Inter mode. Experimental results show that the lossless approach can reduce the encoding time by 7.5% on average. The lossy approach can reduce encoding time by 13.87% on average with average PSNR loss of 0.048 db and average bit rate increment of 0.76%. © Springer-Verlag Berlin Heidelberg 2006.