I have just posted a small and simple guide to the use of AC3Enc to convert a WAV file to a fully compliant AC3 file, usefull when converting an AVI to a DVDR. AC3Enc come with Sonic Scenarist and is very similar to Sonics SoftEncode.
Check it out at http://www.dvdrbase.com/showthread.php?p=192895#post192895
Check it out at http://www.dvdrbase.com/showthread.php?p=192895#post192895