If you're refering to fitting them onto a dvd-5 format 4.7 GB (4.37 GB) disk, then you'd be struggling. I just opened my FCP video app, added 4 hrs (240 mins) of video, & a setting of around 2.0-2.2 Mbps & ac3 at 192 kbps or much less would be required. 4 & a half hrs would definitely only be capable at 2.0 Mbps so ... the quality drop would be quite noticeable. But I still think you'd be struggling greatly to fit them on anyway. It's generally not recommended putting more than 2 & a half hrs on a dvd-5 format disk at absolute most.

If you're refering to a dvd-9 disk (fits about 7.95 GB), then you'd have more chance to do it.

A new option is getting a set-top dvd player which plays mpeg 4. I picked mine up quite cheaply but plays mpeg4, divx, xvid, ... & all I need to do is put such files onto a data dvd & bingo, it plays them. I don't know about Nero but Roxio Toast can convert video files to divx. But I'd prefer just to downld mpeg4 files & burn them to a basic data disk. When you play them, you get a menu similar to an mp3 disk menu. Just select the video you wish to play. Also the skip button will jump to the next video. I tried it out with a disk full of music videos & it was very good. And very handy so I know I don't have to reconvert them to watch them on TV.