Trying to export a video for display on a smartphone in portrait orientation and can't seem to find a way to do this.

I tried rendering to MPEG4 at 720x1280 (instead of 1280x720) resolution to get it to crop but no luck

Rotate and Shear effect (from Crop and transform group) is what you need

http://userbase.kde.org/Special:MyLangu ... _and_Shear