Hi, I'm looking for some help in understanding the implications of selecting hacks with different GOP lengths (GH2). I've done some research and I'm beginning to get to grips with what a GOP is and why you would use different lengths of GOP and (kind of) understand what I,B and P frames are.

What I'm not sure about is this: If I need to render to an MPEG 2 with a closed GOP 15 frames long in format IBBP should this influence which hack I should choose to shoot with? Will selecting a hack with a different GOP structure be ok? Do I just specify this particular structure when I render from my NLE? Or is the GOP structure eternally fixed by the hack I choose to use?

Apologies if this has already been covered or if I'm just getting it all wrong! Any help will be much appreciated:-)

Thanks, Sean.