I've exported a lot of HD commercials in the past few years, but have not had to export an SD spot as a file. Back when I was still doing SD, everything was simply laid off to tape. Now I'm trying to make sense of these specs...
A broadcaster specifies 720X480 resolution and 4:3 aspect ratio. 720/480=1.5 while 4/3=1.33333. I alway thought 4/3 was 640x480. In contrast, in HD both 1920/1080 resolution and 16/9 aspect ratio both result in 1.777777
How should I export the SD video?