This video explains how to format and upload HD (High Definition) video to YouTube using freeware available for PC. The same concepts should also apply to Mac, I have included a link to alternative freeware for Mac users. The tutorial requires a few freeware programs available online: VirtualDub: http://www.virtualdub.org/ VirtualDub gamma adjustment plugin: http://www.thedeemon.com/cgi/getfilter?id=44 (leads directly to download) MPEG Streamclip: http://www.squared5.com/ Quicktime: http://www.apple.com/quicktime/download/ To use the VirtualDub plugin, just extract the .zip contents into VirtualDub's "plugins" folder. VirtualDub isn't available for Mac but the free program Avidemux has similar functionality: http://fixounet.free.fr/avidemux/ I haven't used Avidemux so I can't help you there, but from my understanding it should be able to resize a video as needed for this tutorial. Got a question? Don't hesitate to leave a comment!