An improved block size selection method based on macroblock movement characteristic

Abstract

The H.264 video compression standard supports seven variable block sizes ranging from 4?×?4 to 16?×?16 for one Macro Block (MB) with 16?×?16 size to conduct motion estimation (ME) and compensation. This new feature achieves significant coding gain at the cost of huge computation complexity. Dozens of fast mode decision algorithms with fast block size selection have been proposed to reduce complexity. In this paper, we propose an improved fast block size selection method based on MB movement characteristic. The Motion Vector (MV) and block residual are employed to analyze the movement characteristic of one MB novelly. Then the movement characteristic is used to decide whether and how to merge or split the MB for encoding. Experimental results show that this method speeds up mode decision procedure dramatically with negligible compression performance degradation.