If your stream really needs a codec that isn't available, you'll have
to play it using an i386 version of mplayer. Your stream plays for me,
though. The audio is WMA Pro, which current ffmpeg can handle.
There was some work done at one point to allow the amd64 version of
mplayer to load i386 DLLs, but I think it was never accepted. It ends
up being way to hackish. I don't know what's happening in the area of
x64-DLLs, if any codecs are available as such, and if they can be
loaded by mplayer.