DVD to iMovie?

[Joan Keenan]

HI,
I am afraid I dumbly deleted the last copy I had saved of an iMovie 
video that I had burned to DVD on someone else's computer (so that file 
was immediately trashed too!) Now I have a Cndyne dvd-r & iDVD to play 
with and would like to add chapter markers to it and burn again...Is 
there any way to get the movie back to iMovie. The cheap DVD player I 
have only has  one av out so I can only play out to the TV & then 
record from there which means I am losing quality, or at least I am 
getting the black lines on the side, so believe I am losing quality.
I am new to DVD, so may be missing some obvious step.
Any help greatly appreciated.

Joan