how to find the real audio delay of dvds

[codemaster]

I understand that some dvd's may have a certain amount of sound delay.

But if, for example, I use MeGUI to encode the sound from ac3 to mp4 (or m4a), and the video to h264, and after I mux these 2 streams into a mp4 container, the audio will have a "-200ms" delay if the source audio has "-200ms delay".

The "MP4 Muxer" from MeGUI, has a option to set the audio delay, but how can I find out the exact amount of delay of the source ac3 ?

DVD Decrypter and PGC Demux are 2 tools that I know that can detect the audio delay of the source ac3, but in most cases, the amount of delay reported by these 2 applications is not equal for the same ac3.

[davexnet]

Perhaps DGINDEX ?

[ragivan]

Did you happen to find the answer/fix? I am having the exact same issue.

[jman98]

Did you happen to find the answer/fix? I am having the exact same issue.

I love it when new members show up and they ignore what has been said previously.

davexnet said:

Perhaps DGINDEX ?

It would seem that you have interpreted the ? in his post thusly:
"There is 99.9999999999% chance that DGINDEX will fail to do this and it will be a complete waste of your time to try it"
when what he really meant by the ? was something like this:
"As best I remember DGINDEX can do it, but as I do not have a good way to test it I cannot say with 100% certainty that it is the program you want. But I think it is."

Try it. I think that IFOEdit may also be able to give this information but I do not at this very moment have a way to test IFOEdit for you.

[ragivan]

I love it when new members show up and they ignore what has been said previously.

Hey, sorry I should have explained it better. I did try DGINDEX but I could not fix the issue. So I had just assumed "Perhaps DGINDEX" was just a guess, not a tested solution, which led me to give up on DGINDEX after just 3 trials. I have always used DGINDEX via MEGUI and it resulted in a .AC3 file with DELAY value in the filename. This value was not always true, which is why I am here. Currently I manually try to detect the delay using Vegas Pro. A slow process that cannot be automated but works.

Thanks for stating IFOEdit. I will surely give it a try. This time I will try harder

[manono]

I did try DGINDEX but I could not fix the issue. So I had just assumed "Perhaps DGINDEX" was just a guess, not a tested solution, which led me to give up on DGINDEX after just 3 trials.

Then you didn't decrypt the movie completely and most likely left in audioless unreferenced cells that messed up the audio synch. One possible way around that is using the '[' button in DGIndex when making the D2V and going in a little way, past the initial black frames. Or go back and decrypt over again, running it through FixVTS afterwards to remove those little cells. DVDFab (if that's what you use) doesn't always get rid of them. And the delay as reported by DVDDecrypter is often wrong.