[gunnar]

I have a few clips in MPG format which I can play in QT 7 with the 3ivx and Divx codecs installed but I can't export them to MOV format without losing the sound. Is there a standalone program to do this or another codec I can install to do it? I ultimately want to burn these files to DVD in iDVD.

[Jacke]

Regular MPEG-files don't require 3ivx or DivX.

I haven't tried iDVD myself, but can't you load the files directly into iDVD?

[gunnar]

They won't load into iDVD. The format is MPEG1 muxed.

[Nap]

If you are using at least Jaguar OS X you can use this freeware to convert mpeg-1 to QT formats with the sound intact. Since you mention iDVD you should use DV format as the output from streamclip
http://www.alfanet.it/squared5/mpegstreamclip.html