I have an avi file with ac3 audio. The problem is that it is widescreen. I tried to convert it to mpeg2 with TMPGEnc but the sound quality is very bad. I want to ask if there is a way to convert it with good sound. Someone told me to extract the audio to wave first. But I cannot find any program that extract ac3 form avi to wav.

Please help me to find a way out. Thanks.