Video Editor for simple cropping but works with many formats

iMovie is pretty simple to use. Pretty capable for $15. Check its list of compatible files, and of course there are a number of plug ins that can expand. It doesn't cover everything, however. Some formats will just need to be converted.

There is a video forum here;

http://forums.macrumors.com/forumdisplay.php?f=80

 

I use MPEG Streamclip to cut parts of my GoPro camera vids without re-encoding. It works much faster than iMovie in my experience for that simple task.

http://www.squared5.com

 

Freestyle Crop

Anyone know a video editor that can crop the way you want to, the way you crop a photo? Come on, it can't be that difficult. I watch videos all the time where the format changes.

 

Even if the movie cropping sounds simple, it will require the re-encode of the full movie. Esp with current packed movie formats.
Also, AFAIK, you just can't change the frame size mid-stream. A movie has a fixed frame size throughout, declared in it's header.