From ML forums:
"The best you can with 600D (550D/60D) is: (limited by hardware SD transfer rates)
- 960Ñ…540, upscale it to 1280Ñ…720 (24 fps max) - 1280Ñ…400, tight aspect 3.20:1 (24 fps max) In Canon's 720p - lineskipping 1.66Ñ…, so you should upscale to restore correct ratio: - 1280x400 upscales to 1280x664 - near to 16:9 (24 fps max) - 1280x360 upscale to 1280x600 - 2.13:1 aspect - 1280x320 upscale to 1280x533 - 2.40:1 cinemascope aspect It is only 1280px wide, but pretty nice looking though"