You can compress the DVD video copying like in the old days of VHS that had SP, LP, and EP speeds (2hrs, 4hrs, 6hrs). But just like those modes, the longer the recording mode, the lower the quality as the video is compressing more data into the same regular SP 2hr space.
The same is with a standard single density/sided 4.7GB DVD except they are modes are different. Depending on media and DVD burner, you can have 1hr, 2hr, 3hr, 4hr, and 6hr for audio only. I haven't done it in years but I used to experiment with quality settings a lot recording from old VHS tapes to DVD. These times are all at standard 480p 4:3 DVD format video originally taken of course. If your burner has double density (layer) DVD burn capability, you can buy double density DVD media and double those times.