Theora problem: videos w/ x 1024 and beyond is choppy on TGE 1.5

Hi can anyone help me find some way to tweak or fix this? I'm guessing this is now a C++ thing and I need guidance. I know a fair amount of C++ but I have no experience dealing with video playback/streaming code.

So the problem is, I need to do a non-choppy playback of Theora videos that has width 1024 and beyond. I have a powerful machine so I guess it really isn't the machine's fault.