Hi all, I little tested uManiac build 15.1.2003 15:00. I have interesting result: Use chroma motion decreases filesize in fixed-quant mode (q=4). Some time ago I noticed this in connection to B frames, but now it is also true for QPEL+CHM, and GMC+CHM. GMC increases filesize... TonyMi P.S. My test clip is Mummy, frame 1-1000, 710x428 pixels (i.e. only cropped).