I'm at my job and I have no cable, so connecting my iPhone with my computer is not possible.
I have tried emailing the video, but the iPhone is compressing the video. It is not jailbroken.
Is it possible to transfer the original video?
Emailing full resolution photos or videos
On your iPhone open your camera roll and navigate to the overview screen where all your recent captures are shown via small square icons. Press and hold on the icon for the video you wish to move to your computer and select copy from the pop-up menu that appears.
Still on your iPhone open Mail and create a new message. In the body of the message, press and hold the cursor, and select paste from the pop-up menu. The message you send will now have the full, unadulterated video attached which you can download on your desktop.
Note: on my iPhone 4 I created a 4 second clip with very little motion and it used 6 MB. You may hit your attachment limit very quickly depending on length and resolution.