Cropping while capturing?

I'm looking for a way to crop footage while I'm capturing it.
Every time I capture something from my camera, there's a thin black line to the far left of my footage. I've always had to manually crop this before exporting my movie but I would like to skip this step by removing it instantly during capture instead.
It doesn't matter if the aspect ratio gets a bit stretched because of this, the crop is very minor anyway.
But is there a way to do this? And if not in FCP, perhaps with a plugin or different editing software?