does anyone know how to do this conversion? i read a few guides online, but so far i haven't gotten anything to work...

usually TMPEG Encoder can convert the Xvid file directly to MPEG video. Both MPEG1 for VCD or MPEG2 for DVD. For the ac3 you have to check if it is 48Khz. If so you can just use that audio for the DVD audio stream.

VirtualDub should be the best tool to split the ac3 from the xvid video for this. Just download virtual dub and open the file. Then under "audio" select "Direct Stream Copy". After that save only the audio with "File"->"Save WAV"

You should then have 1 audio stream in ac3 and the MPEG2 from the TMPEG Conversion.

Now you only need an authoring software of your choice and author the disc.

For VCD just decode the ac3 that you got from virtualdub to WAV and then to MP2 (not MP3) at 44Khz and combine the MPEG1 video with the MP2 audio using MPEGtools in TMPEG (File->MPEG Tools->Multiplex)

if you have detailed questions, go ahead .. .

thanks a lot, looks like it should work now... you've been a lot of help!