A split and merge algorithm for inter-mode decision in extended macroblocks

Extended macroblock size (EMS) improves the highest possible coding efficiency for the current video coding standards, but a large number of additional candidate coding modes results in high computational expense. In this paper, the correlation among different modes is exploited to drastically reduce the number of candidate modes in EMS. And a fast inter-mode decision algorithm for EMS is proposed based on above facts. Furthermore, a split and merge technology is used to find the optimal partitioning with computational efficiency. Experimental results show that the proposed fast inter-mode decision algorithm reduces the computational complexity significantly with negligible coding lost.