First it would require an Intel Mac, and it's not clear which of your computers you're asking about (but certainly not the G4).
Second, Bootcamp was only releasd for a short while for Tiger as a beta version. After the test period expired, anybody who wanted to use BC was expected to upgrade to Leopard.
G4s sadly do not have the horsepower for video or audio playback on Windows emulation.
If you desire to use an application that uses either of those, you are better suited to get a minimum Intel Mac.
See this FAQ* on available options: