If final file size isn't a big deal (since you're playing from a hard drive or thumb drive) then get rid of 2-pass VBR (Variable bit rate). Do a CBR and set the data rate at 16mpbs.
You can also shorten you keyframe distance down to your frame rate (or even half your frame rate). Typically I do keyframe distance at the frame rate - 24, 30, 60, etc. That way every second I'm guaranteed an I-frame as it encodes.
Ryan Holmes
http://www.ryanholmes.me
@CutColorPost