[MPlayer-dev-eng] dev process general question + perf with sdl and windows

[zze-projet AMIRAL AKHRES N ext FTRD/DIH/REN]

can someone tell me how to make a patch?
how does a patch work?

is it a kind of script, just copying new .cpp and .h?


another question: i have made some benchmark tests with -benchmark
and windows(cygwin)+mplayer+sdl [vo] = 25% cpu usage
    windows(cygwin)+mplayer+directX [vo] = 2,4% cpu usage 
    linux+mplayer+sdl [vo] = 2,2 % cpu usage
Has someone any idea why such results?
Is SDL very bad under windows os?