You can put about an hour on a 4.7GB DVD if you use the highest legal bitrate (which gives the best possible quality). You can put lots more on the DVD if you lower the bitrate (in either the Vegas render "Custom" dialog, or in your DVD creation program, like DVD Architect). For high quality video, you can go down to bitrates of about 6 mbs, without too much degradation. For lower quality video sources, you can go down almost to 4 mbs. This gives you 1.5 and 2 hours respectively.

I suggest doing a sample render of your video to a DVD-RW and then viewing this on a big screen TV so you can decide if the quality at the lower bitrates will be acceptable.

Just to give you a ballpark idea based on what I've done for personal use. Using Vegas 4 and the MC DV NTSC template (default settings) AND rendering as a MPEG-2 (combined audio/video) I typically get:

5-7 mini videos total playing time 75-85 minutes. This includes:

1. a main menu page with 5-7 automated thumbnails, one for each video
2. a 30-60 second music background (looping)
3. a sub menu page for each video ranging between 4-9 thumbnails each
4. each sub menu page has background music, again 30-60 loop
5. a gradiant background for the main and sub menu pages (same)

I let DVD-A recompress the audio steam. While the building stage varies, the processing time (rerendering of audio and image file creation) takes on average about 52 minutes and the actual burning of the DVD another 20 minutes or so, though I never timed the burning exactly. This will come close to maxing out a DVD at roughly 4.6 GB, or to look at it another way, once burned if you flip the DVD over and look at the bottom you can see it is burned to within a 1/16 of an inch or so of the edge. You want to avoid going to where DVD-A shows a full 4.7 or even 4.6 in the lower right corner or it may need to recompress some of the video which you want to avoid. So you have a "full" DVD once DVD-A is saying you've got 4.4 to 4.5. The difference is overhead.

If you are going to add a music background to the main and sub menu pages, it is worth the samll effort to render them out to only the length you have you menu pages loop, otherwise they will waste a lot of space on the DVD. If you don't have songs that are appropriate most of the SoFo applications come with several loops of appropriate size. Also, if you plan on looping add several seconds of silence to the end of each when you render in Vegas. To get the music to repeat all you have to do is check both the auto caculate option and the looped option then if you make a animated thumnail it will run the same length of the music.

Thanks people!
Just to be sure

higher bitrate = Less time on disc right?

Everyone here use Vegas program? I don´t know that, I use Win Mpeg e TMPEGen to conver videos. Does Vegas do that? What is this program for!?
Thanks a lot people!

The higher the bitrate - the less time will fit on the DVD
The lower the bitrate - the more time will fit on a DVD

Vegas, DVDA, or TMPGenc can be used to encode the MPEG2 file. DVDA is used to AUTHOR the DVD. Vegas is used to EDIT the video.