I have a 19G quicktime that I want to encode as a DVD. Will DVD Studio Pro encode that to fit on a DVD or should I bring it into Compressor and encode as a MPEG-2? Once in Compressor, what settings should I use? Would it be better to use Squeeze?
Use Compressor. It's designed for encoding MPEG2 for DVD. You can have DVDSP do the encoding for you but it uses QTs encoding engine which isn't great. The bitrate depends on the LENGTH of your material, not the size of the source file.
I agree, use Compressor. Best Settings 150 or 120 minutes. I don't know if you said how long it was.
Bitrate is also effected by size. If you check how you are supposed to encode H.264 in Apple's docs they will always tell you to slide the bitrate up as the frame size gets bigger. Even if the length is exactly the same.