Hey Theskid,
1> use virtualdub and input your .avi file.
2> select audio tab and choose "Direct Stream Copy"
3> go to File and select "File Information". Check file type.
.....if unknown then its .ac3 else it's .mp3.
4> Select "save as wav" in File and enter file name .wav
5> After extraction rename file based on 3> as .ac3 or .mp3.
6> Input file (.ac3 or .mp3) to Besweet and create uncompressed
.....wav file. You'll know because the file size will be much larger.
7> Input .wav file to Headac3he and create output file as .mp2
.....(dual channel), 48Khz, audio bitrate,etc.,etc.,etc.
This may seem like alot of steps, but when I searched for answer,
this was the best. Note: Besweet does not support "dual channel"
and that's why I used Headac3he to convert to .mp2 instead.
-black prince