Also, some TVs have zoom to correct the lettered pillar boxing that happens when a 16 by 9 source ended up letter boxes for 4 by 3.
Handbrake's auto cropping of letter boxes and pillar boxes is my favorite video tool feature of all time. My god do I love it.
...except when some douch nozzle stuck a channel bug in the pillar box area and fucked up the auto crop!