How to change the shutter speed on Canon Rebel t3i for FILMING?

And no, the manuel says nothing about it. I scanned it for atleast a few hours. When you turn the wheel to TV and M settings, you may adjust the shutter speed as you wish, but I cannot film, only take photographs. When the wheel is set back to the filming setting, there is no difference in shutter speed. How can I adjust the shutter speed which is set automatically? If I can't, how may I film with a good 1/1000 shutter speed? I'm a big time director student and I would appreciate the help thanks.