Line up a raw still with video frame grab.

I have a still taken with a canon 60d. I also have movie footage, taken from exactly the same position. I want to match up the still pixel-for-pixel with the footage. The difficulty is that the still is 5184x3456 = 3:2 and the movie footage is 1920x1080 = 16:9

What I want to do, is take the still into Photoshop and crop/resize it so that it is 1920x1080, and it has a pixel-for-pixel match with the movie footage.

Looking at a screengrab from the footage, and comparing it to the still, it's clear that the still is cropped, but I haven't been able to work out exactly what sequence of actions will match the still to the screengrab.

A further complication is that 60d actually records at 1920x1088, not 1920x1080, although After Effects seems to ignore this.

Any help would be much appreciated.