Variable block size selection for a transcoder based on MB movement information
Xiangwen Wang, Jun Sun, Rong Xie, Shibao Zheng, Songyu Yu · 2008
To improve coding performance, the new video compression standard H.264 employs seven variable block sizes for one Macro Block (MB) to conduct motion estimation and compensation. MPEG-2 only has one size 16×16. This paper presents a novel fast variable block size selection method for an inter-MB in a video transcoder from MPEG-2 to H.264 with downscaling by a factor two in each dimension based on the MB motion information. Without conducting motion re-estimation, an optimal block size is decided. Experiment results show that this method saves the transcoder complexity dramatically with little compression performance degradation.