"I converted it to a DVD image,not an iso with DEVEDE"
i'm sorry, i can't understand what you wrote well, if you created a dvd image it must be a .iso file
if all you did was convert a flv video to a avi video file, this is not a dvd image, it is just a avi and you can't burn it as a dvd image, you can burn it as a avi file and then watch it on a normal dvd player but it will not be a dvd video, it will be a file in .avi(or mpeg/mp4) file that will require that the player can play divx files(most of the recent dvd players can do this since 2007)
if you must create a dvd video, open again devede and select create dvd video, select again the flv file and let the process create the iso you need, the iso can be burned by any burner app including brasero, k3b and other apps
the iso you are creating, try it first in a dvd-rw, as you are learning to use the app, you can end up wasting dvds while you create what you want