fixing clipping in AC3

[brett]

I'm doing a rip of Swingers, and the audio is regular AC3 48 kHz 2.0 ch (DS) 192 kbps. I ran it through HeadAC3he, transcoding it to an MP3 with the --alt-preset standard settings (came out to about 160 kbps). I scanned through the MP3 in Winamp just to make sure everything went OK, and it just sounded a little tinny here and there. I jump to the trailer scene (Chapter 5), about 23:30 into the movie, and there is a spot where a conversation gets really loud. Therer was some REALLY bad clipping.

So, I figure I screwed something up, or maybe I stumbled across a bug in one of the programs I'm using. I tried demuxing in both SmartRipper and DVD2AVI. I tried re-encoding the MP3 in 2-pass float mode with 93% normalization, 100% normalization, in 1-pass mode with no gain, with light DRC, with no DRC, with Surround, Surround 2, and Stereo downmixing... I was even doing a pass downsampling it to 44.1k (although I'd tried playing it on 3 different sound cards), when I decided to pop the DVD into my set-top Sony. I go to the trailer scene, and guess what! The problem is in the DVD audio, not in the encoding.

Any suggestions? I'm not expecting any sort of miracles, but is there a good way to smooth out the clipping? Maybe decode the AC3 to a 32-bit WAV and then do some filtering in SoundForge before encoding?

[DSPguru]

you first need to eliminate the problem - is it with the decoding process ? or with the later processes (drc/src/encoding to mp3).
try decoding the ac3 to wav and look for those clips. if they're there, try decoding with dvd2avi.
post your resluts.