AC3 attenuated when ripping/demuxing

[lemmy999]

I have a DVD+R from friend of a concert he recorded. I ripped with DVD Decrypter to one .VOB file. Then I opened it with MPEG2VCR and demuxed to AC3 and .mpv. Then I open the AC3 in Softencode and the sound levels look really low. I convert to WAV (with softencode) then open the WAV in Cooledit. Sure enough the peaks are around -18dB. I do some soound processing, then amplify to about -5dB peaks. Then I use Softencode to convert back to AC3, then I use SpruceUp to author the DVD with the new AC3 file. However, when I play the DVDs on my DVD players, the original one is moderately louder than the new one I made. Where did the attenuation happen? Is it when I ripped with DVD Decrypter, or when I demuxed with MPEG2VCR? Somewhere I lost more than 13dB in the audio (by the time I opened it in Softencode). Thanks for any suggestions.

[Soopafresh]

I wonder if the app is truly "demuxing" into 5.1 channel AC3 or if it might be bouncing down to stereo 2 track and creating a new AC3 file. If you use DGMPGDEC , I believe there is a choice to normalize the audio during extraction.

[lemmy999]

The AC3 is 2.0 AC3, not 5.1. So it is going from AC3 2.0 to 2 channel PCM (WAV)

[Soopafresh]

Still, use DGMPGDEC and choose the "Normalization" function when demuxing the audio. There is a tab under "audio" that you'll want to check box. That should bring audio levels up to 0 db.

The latest version is here: http://neuron2.net/dgmpgdec/dgmpgdec130b5.zip

[lemmy999]

Thanks, I will try that.