If you are gonna use Quicktime on Mac OS for the player .
Consider using DirectSound (Directx sound module) on the Windows version .

For one it doesn't hog that much resources as Quicktime .
Most people have Quicktime itself set to use DirectSound on Windows .
So if you use Quicktime , lot's of systems will load both Quicktime and Directx .
A waste of CPU time if you can pass the sound on to DirectSound in the first place .