Thanks, but I should have mentioned that the blocking goes away when I decode with "Raw Framebuffer." Maybe Raw Framebuffer uses some sort of higher-quality color pallete downscaler?
Besides, this problem doesn't occur on my good old x3 basic... that is, when I set the speed to 50% and it can actually play the file, it looks just like the original (as far as my eyes can see

). This happens when dithering is disabled and everything! :hide: :hide:
Hm... last I checked, XviD didn't support 16-bit encoding. I think it only supported 24 and 32-bit.