What kind of emulator you are talking about? I like emulator with good tools like VBA. Seriously my system don't have anything to record screen!but I can record with that.(never record with out compressor or 5 minuets become around 3 gig!)It depends. It can either take a couple hours or days, depends on how far you're willing to go.
These ones wouldn't fly on those TAS forums, I'll tell you this much.
I'm not really a frame by frame expert, so much so that the stuff I did in the video is mostly practical, if we're talking about combos and whatnot. There's definitely more dedicated people out there.