You can.

You have to make the video a .pmf file (like V1 said)

And adjust the opening_plugin gboot timing.

http://forums.dashhacks.com/f134/a-simpl...a-t298038/
From there you can create a 5.xx opening_plugin with the timing set to your gboot's.
You can convert the opening_plugin to 6.xx with CTFGui.

Thanks, I'm about to look into it now. Sorry for the late reply. Been gone for a week and didn't notice anyone replied.

[edit] "You can. You have to make the video a .pmf file (like V1 said) And adjust the opening_plugin gboot timing."

That's what i have been doing. The problem is that i can't make 1 minute long gameboots.