I've been using TMPGenc plus to encode my DVD material from NTSC 4:3 DV, but as I'm always improving my methods. I'm a little confused about the source aspect ratio to choose... the help file shows these options for 4:3.

4:3 525line (NTSC) 352x240, 704x480, 720x480 NTSC sources
4:3 525line (NTSC, 704x480) 352x240, 704x480, 720x480 NTSC DV capture video
4:3 Display A source film in a 4:3 aspect ratio

It seems that I should select the second one but the 704 figure throws me. I checked it out on my TV but it's hard to discern what's correct when the difference would be small. Can anyone give me a theoretical answer or shed any light on this? I could ask on pegasys but I figure you guys would be faster