AC-3 file header errors?

[DRP]

I've got this AVI file I'm converting to DVD. No dramas with the video. The audio in the source AVI is AC-3 (presumably the raw file that was on the DVD that was ripped originally to make the AVI). When I just re-used the AC3 source audio, completely unaltered, in the new DVD compilation, the resulting burnt DVD plays in both PowerDVD on the computer and in one of my standalone hardware DVD players with no audio at all. No error messages or anything, just no sound at all. It's like the player software just doesn't recognise the audio format as being compliant AC3 audio. In my other Sony hardware DVD player it plays fine with normal sound as you would expect.

Authoring was done with DVD-lab PRO and normally with that software it checks the source AC-3 files for errors and will give an option to correct them if errors are found. I got no such message with this AC3 file when I went to add it into assets.

Can anyone recommend me any other software that's able to check the validity and compliance of AC3 files so that I can try and find out what might be wrong with this one?

[lordsmurf]

I don't know of an AC3 compliance-check tool, but know that most freeware-created AC3 (and even some commercial sources, such as older Panasonic DVD recorders) are out-of-spec AC3 -- at least according to how it reacts in software that refuses to accept or properly work with full-compliant Dolby. Some of this is documented, or at least was online in years past. I came across AC3 problems probably 5-6 years ago now.

For this problem, I suggest importing the audio into Womble MPEG Video Wizard, and then export the timeline (just the audio!) to a new MP2 file. Then you can take that MP2 and either keep as-is, or re-encode to WAV or a new AC3 for the DVD.

For compliant AC3, I suggest this encoding method: http://www.digitalfaq.com/forum/showthread.php/encode-audio-ac3-1465.html

DVDWS2 also gives no-sound or otherwise corrupt AC3 output if the AC3 input is out-of-whack. Authoring apps can be picky to specs.