Copy from IRC and thresh's blog
From Dark_Shikari.
Absolutely 100% generic commandline for maximum quality without stupidly insanely slow options: –bime –bframes 16 –trellis 1 –mixed-refs –8×8dct –subme 7 –b-rdo –me umh –direct auto –b-pyramid –weightb –threads auto –ref 8 For extra slow, add –no-fast-pskip, –merange 32, and –partitions all for more slow, raise –ref to 16, and –me to esa and also, get the latest AQ build and use my AQ at strength 0.7-1.0 or something. if you want faster encoding 1) Lower –ref to 4 2) lower subme to 6, remove –b-rdo 3) remove me umh if you want realtime encoding you’ll have to go lower on most machines