I had a hard time compiling the 'skater' and 'a5steroids' exemples in Windows because MSC compiler was complaining about multiple copy of _main function in 'barkmel.obj', previously defined in skater.c and a5teroids.cpp, respectively. Just commented out main definition in vorbis/lib/barkmel.c and it solved the problem. I'm just thinking that others might have the same issue, so here is the solution.