I think OS4Emu just allows the binary to start up and then it gets handed over to MorphOS' SDL libraries.
Yes, this is how OS4Emu works, sort of. It really is like Wine on x86 linux, it doesn't actually "emulate" anything (as in CPU emulation). Basically OS4Emu is just bunch of wrappers to redirect OS4 library calls to MorphOS native functions. Since there is no CPU emulation involved, the speed is equal to OS4 itself on similar hardware.
If you run OS4Emu on 1GHz PegII, it's actually faster than any stock "AmigaOne" ;-)
Nice video, btw.
[EDIT] However, in this case I think OS4 SDL library is a statically linked one, meaning that the SDL calls won't be translated to MorphOS SDL calls. The translation happens at lower level. The end result is the same, though. [/EDIT]
