I have had much trouble finding good documentation on how to take video from various resolutions to burn onto disk. If I want to burn a 640 × 272 Creative Commons movie onto disk, should I have it stretched out to 720 × 480 for DVD and expect that my TV will know to shrink it vertically so that it appears in widescreen? Or should I simply strech it to 720 × 306 so that it is stretched evenly (not distorted), and then add in 87 pixels of black above and below so that it is displayed as widescreen on my TV? I am using ffmpeg to convert the downloaded file to MPG and to resize the image. I am using K3B to put that on disk.

If you're using ffmpeg why not just specify the -target option?

i.e.

ffmpeg -i old-movie.mpg -target pal-dvd new-movie.mpg

I'm pretty sure there is a target type for widescreen dvd format but can't remember what it is. I'll have a look when I get home.