Audio delay / lip sync

[mikemcc]

Can anyone please tell me the best way to measure audio delay accurately during / before a DVD rip ? I'd happily use DVD Decrypter but, eg, it says the delay is 371 ms whereas I have to enter a 200 ms adjustment in Tmpg Xpress to create an mpeg2 file which has perfect lip sync using PowerDvd or WMP.

Perhaps I need to understand what audio delay is a function of. Thanks for any help.

[plomon]

rip a small part of audio using Rejig(download here (http://www.afterdawn.com/software/video_software/video_tools/rejig.cfm)). it tells you the audio delay in it's file name itself.

[mikemcc]

Thanks Plomon. Looks like good advice; I've used ReJig once and it worked fine. You don't even have to start the rip - it specifies the delay immediately you specify the VOB. I'll update this thread only if I find it doesn't work all the time. Hope you're enjoying the cricket.

[j7n]

I have the same problem. Audio is usually delayed by 2-8 video frames or smth like that. Where does exactly ReJig display the delay? Do I need the full DVD to detect it, is there a way I can do it from MPEG2 without the *.ifo files?

[mikemcc]

Sorry, I should have posted back, saying that ReJig *doesn't always* provide the answer, but did help me. I can't get back into it now, but my notes tell me that in ReJig I selected:
File mode, add, select VOB, done
and it showed me the audio delay.

I have always *imagined* that you need to read from the DVD to find the delay, as the delay "emerges" only when you rip from a DVD. But I'm no great expert.

Hope that helps a bit.

[j7n]

Forgive me if I missed something but I can't see the delay value. :(
I have always *imagined* that you need to read from the DVD to find the delay, as the delay "emerges" only when you rip from a DVD.
The VOB files I have play fine with Elecard + AC3Filter. So I assume all the required information is already in the MPEG-2 stream.

After conversion to X264 with VirtualDubMod 1.5.10.2.2542 a random negative audio delay is introduced. It's like there was no audio for a few frames at the beginning. There was one example where no delay ocurred (I don't know why), AC3 bitrate was 192 kBit/s in this case.

I don't mind using a hex editor and a calculator rather than a one click solution. It'll be alot faster that delaying the audio a bit, testing carefully, delaying again, etc.

Thanks for any comments in this matter.

[mikemcc]

Sorry not to get back sooner. In ReJig:
Select file mode, add
Select VOB with audio, done
See the audio delay
Hope that helps

[j7n]

You were right, MikeMCC.
It appears that the delay I was talking about was caused by VFW compatibility mode for H.264. I read about it here:
http://forum.doom9.org/showthread.php?t=99033