Ever had TMPGENC convert an AVI file and have Video but no sound in the resulting MPG (ie for VCD conversion). Ever had the general problem that you have a working AVI with Video but no sound? I found that the following simple solution solves this for many AC3 or other video files with compressed sound. 1. Download "AVI2VCD" v1.4.2 or later. This comes with (or came with at the time of v1.4.2) - a "decompress.exe" utility which decompresses quite a lot of AVI files that I've had trouble playing sound for ie stuff that uses surround or other issues. I've never had sound / video synch issues doing this either. I can recommend this as a simple strategy for solving some basic sound compression stuff. Believe it or not, I have experienced this strategy solve the prob where you can't view the video for some files (ie somehow the sound compression issues prevent windows from displaying the video correctly). Also - the link that Dela provided below is very cool - in particular the section which points to "GSpot" a utility which interogates the AVI and provides info on the required codec and formats needed to successfully convert the file. I still have a couple of DivX5.0 issues for one or two AVI files - but the above solves a hell of a lot of issues. Also DVDx2.0 is a nice "one step" VCD converstion program (straight from DVD) if you are looking for one....not quite the quality from the multi-step manual conversions I've been doing...but close.