Sure, Mplayer can be compiled to ppc64 with gcc with minimum effort.
But you can not create xex with gcc. You need the microsoft compiler which don't implement C99.
And sure, you could patch away all C99 specifics manually (a couple of hundred patches at least) but then you will be stuck in that exakt version of mplayer/libavcodec or whatever.
My initial thought was to simply just "compile libavcodec with VS2005", but it turned out to be something different.
BTW, libavcodec is a big part of mplayer.
So right now I am thinking of either making a script that fixes most of the C99 stuff ( With some help, thanks

).
Or some compile "magic", compile libavcodec with llvm-gcc, and then use the "c-backend" of llvm and output generic c-code that VS2005 should understand
Or a different trick, compile libavcodec with gcc for powerpc64 and just load it into memory from a xex compiled with vs2005. This will require some "glue" code to be able to call functions between VS2005 compiled code and gcc. I have not researched anything on the details about this, specifically the calling conventions for functions might be a problem.
i think i mght be able to assist. Unlike the rest of these slackjawed gawkers with their hands out, I have years of coding experience, and am willing to roll up my sleeves and do some work to contribute to scene. Let me know some specifics of what needs to get done, and I can do my best to help out.
I have heard rumor there is a patch out that will get the sdk working with vs2008, I'll see if I can track it down. If we can get that, it should make our lives a little easier. In the mean time, let's figure out a definitive direction to work. It's nice to have options, but it is best to focus.
To the 2 pages of people asking why this isn't out yet, and when is it being released, or how the progress is: Pick up a fuckin book and learn how to contribute. Asking when something will be released is not helping the scene. Learning how to code will. I acknowledge I have not released anything, but I am at least trying. I started coding when the xbox1 first got hacked, because i wanted to contribute. Put down the controllers and pick up coding book. /rant