I want to create a DVD from several VCD's, sticking to the VCD quality and so get a DVD with about 400-450 minutes of MPEG-1 video.

I downloaded Movie Factory 2 and Isobuster.
I use Isobuster to convert the .DAT-files from my VCD's to compliant .MPG-files, using the option "extract but filter only m2f2 mpeg frames" as instructed.

After the .MPG-files are saved, I open Movie Factory 2 and start adding the .MPG-files to my DVD layout. At this point, I notice that they take up quite a lot of space. For instance: a 200 Mb MPG-file takes up about 400 Mb on my DVD-layout. In this way, I can only get about 250 minutes of VCD-quality video on my DVD, in stead of about 450 minutes.

I know I can change the MPEG-settings to the VCD bitrate of 1150 kbps, but anyhow, when I go on and try to burn a disc, Movie Factory will always start to "convert video", which takes a whole lot of time.

Does this "convert video" mean that it's just converting the audio to the needed 48 kHz, or is it actually recompressing my MPG-files?

Who can help me out here? I have several guides (from vcdhelp, etc) on how to use Movie Factory 2 to burn several VCD's to one DVD, but they don't mention this.