If you only require a DVD you could try using something like the Nattress plug in.
It works pretty well but it does have some limitations and could be a long render.
I have used it on short clips and odd shots and for that it can be a life saver. Never tried it on anything longform - others may have experience of that.
To be honest the only proper way to do this is by using a hardware standards convertor, certainly if you were supplying something for broadcast, I would be looking at using something like Alchemist PHC