Quick Question RE: AutoGK and DVD Decryptor

[ron spencer]

Super program...just started with it....


curious about one thing though....does AutoGK use the delay information that DVD Decryptor provides in its stream information text document? For example if there is a delay of -105ms in an AC-3 stream will AutoGK take this into account when making the AVI?

If so, I guess you could edit the delay in the stream info file...

[unskinnyboy]

Most of the times, no.:rolleyes:

[neuron2]

Ron, please observe forum rule 9 regarding thread titles. Thank you.

[ron spencer]

sorry neuron2....I fixed the title....

[len0x]

AutoGK doesn't use the delay from stream info file, but rather from audio file name demuxed by DGIndex. Do you have any problems with that?

[ron spencer]

well....I just noticed that the audio file left over after an encode (128kps mp3) had the delay written as part of its name. this delay was the same as in DVDdecryptor....so somewhere along the way something read the stream info file...this would be DGIndex, so the result is the same....

I did notice that I had some audio sync issues with one of my kids dvds..off by a bit with V1.92...I tried another dvd and that worked ok....maybe I will edit the DVDDecryptor stream file of the problem dvd to make the audio delay 0. If DVDDecryptor messes up the delay somehow then the resulting AutoGK encode will be messed up as well if DGIndex reads the file....I am assuming DGIndex does read the file as the AutoGK tutorial says to output the stream info?

thanks!!!

[unskinnyboy]

IIRC, DGIndex does not use the stream info file generated by DVD Decrypter. It directly parses the VOB files to find the delay and then generate the filenames for the demuxed audio tracks.

That's the reason why sometimes you get A/V desync in the final .avi. Most of the times DVDDecrypter would be correct in calculating the delay, but sometimes DGIndex would miss it. Since AGK goes as per the DGIndex file name, it muxes the final .avi with the wrong delay (or no delay as the case be) resulting in A/V desync. If this happens you have to reinterleave as per the delay value outputted by DVD Decrypter and it would work.

[len0x]

Originally posted by unskinnyboy
Most of the times DVDDecrypter would be correct in calculating the delay, but sometimes DGIndex would miss it.

That's not true. Sure, some beta version had problems but everything should be fine now. In fact, very frequently DGIndex corrects starting 2-3 frames that were not previously decoded by DVD2AVI and therefore delay from DVDDecrypter can no longer be used.

[unskinnyboy]

Originally posted by len0x
That's not true. Sure, some beta version had problems but everything should be fine now. In fact, very frequently DGIndex corrects starting 2-3 frames that were not previously decoded by DVD2AVI and therefore delay from DVDDecrypter can no longer be used.
Know what, I believe you must be right there. It has been more than a month since I have gotten a desync issue in AGK. And there has been numerous updates to DGIndex since then. So guess the issue would have gone away for good now.:D

P.S: Has there ever been a case where DVD Decrypter and DGIndex both reported different delays but DGIndex was right and DVD Decrypter was wrong? Just curious.

[len0x]

Originally posted by unskinnyboy
P.S: Has there ever been a case where DVD Decrypter and DGIndex both reported different delays but DGIndex was right and DVD Decrypter was wrong? Just curious.

Yes and no. Have a look at Q13 & Q34 of FAQ in DGIndex forum...
Short answer - delay from DVDDecrypter may be incompatible with output of DGIndex in some cases and therefore should never be used.

[ron spencer]

so I guess then that we do not know how the delay (if any) is calculated? I guess the only thing for me to try is to edit the stream info file in DVD Decryptor....I will set the delay to 0. If it works then I would have proven that the delays are obtained from DVD Decryptor. If not, then DGIndex is doing something wrong. Also on the "if not" this would mean that you could rip in any fashion you like no? If the stream info file is not used what else is there? Just the IFO file...is this used?

I gather there have been sync issues before....maybe as a suggestion you could somehow make a "sync override" where the user could enter an audio delay with 0 as the default? This is an interesting problem. My hunch is that any DVD with an audio delay that is not 0ms will present a problem....

any other suggestions before I try my test as stated above?

[unskinnyboy]

@ron, I don't think you read this thread properly. len0x clearly says that AGK does not use the delay value from the stream info file generated by DVD Decrypter. It uses what DGIndex gives.

When the author of the program says that his tool does not use the delay which DVD Decrypter outputs, you say you will prove otherwise?:rolleyes:

Bottomline: You need not worry about any delay values now. It is taken care of automatically by DGIndex/AutoGK combo.

[ron spencer]

yes I did read it properly....we do not know how the delay is calcuated, but we do know that AutoGK gets it from DGIndex....does DGIndex find it by itself or does it get it from the stream info file from DVD Decryptor?...if from DVDD then AutoGK gets its info from DGIndex, which gets it from DVDD, which is the same as saying AutoGK gets it from DVDD ;)

in any case something is wrong with this particular movie..no big deal just curious...

as to my experiment....If I change the stream info file and my new avi works, then I have proven that DVDD's stream info file IS used after all...I do not care by whom, just that it is used...and in this case not as it should if the movie is fixed.

Now....if the movie is not changed, the I have shown that DGIndex is somehow messing up the audio sync for this particular movie....why I do not know; which is an issue in and of itself...should be no sync issues if the DVD plays properly and if audio sync is figured out via AutoGK eh? :D

anyway to quickly reinterleave?

[unskinnyboy]

For a movie for which DGIndex reports a delay when run as part of an AutoGK encode, move the VTS_01 - Stream Information.txt out of the current directory to some other place. Now run DGIndex.exe manually on the VOBs and check the name of the audio track created.

This should answer your doubts.

[len0x]

Originally posted by ron spencer
does DGIndex find it by itself?

yes! delay from stream info file is not used by any tool within AutoGK. And I say again: delay produced by DGIndex may not be the same as in stream info file, but that doesn't mean one of them is incorrect (see DGIndex FAQ). It just means that delay from stream info file cannot be used with videos produced by DGIndex/DGDecode combo.

[ron spencer]

so what can we do here?

I demuxed the files into .m2v and Ac-3 (original movie files) and recomipled them in DVDLab ignoring the delay DVD Decryptor gives....result was perfect sync, which means that DVD Decryptor has botched the dealy. Now if DGIndex also botched the delay this means that it could be an issue for other movies....is there a way to tell DGIndex what delay you want? Could be a cool feature in the AutoGK Advanced settings...that is "Force Audio Delay" and then the user could enter the delay which would override anything DGIndex finds...as I suspect this is a case where the delay is found incorrectly.

[unskinnyboy]

Let me try to be practical here.

When would you know that DGIndex b0tched the delay? After the full encode and checking the final .avi, right? At that point would it make better sense to re-interleave the .avi in VDM/Nandub/AVI-Mux GUI if you know the delay OR to go back, specify the delay in the "advanced settings" (if such a feature is implemented) and do an encode again? I would think the former.

P.S:
1) I think you are worrying needlessly.
2) Your whole concern is negated by what len0x said about DGIndex not being incorrect anymore reg: calculating delays.

[ron spencer]

you are absolutely right....I was just interested that is all.


Do you have a tutorial/link on how to re-interleave by changeing the delay?

thanks for all your responses....:)

[unskinnyboy]

--> Estimate the amount of delay in seconds..let us say the Audio is ahead by 2 seconds.
--> Open the movie in VirtualDub, press Ctrl+I
--> You will see 'Audio Skew Correction', Delay Audio Track by ___ ms .
--> Enter a value of 2000ms here. This is equivalent to 2 seconds.
--> Select Audio--> Source Audio and Audio--> Direct Stream Copy
--> Select Video--> Direct Stream Copy
--> Press F7, save using another name.
--> Check new file, if sound is in sync, delete old file. Else you have estimated the delay wrongly. Re-estimate and try again.

[ron spencer]

thanks :)