Audio delay / lip sync

mikemcc · 10th March 2006, 01:20

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 · 11th March 2006, 05:25

rip a small part of audio using Rejig(download here). it tells you the audio delay in it's file name itself.

mikemcc · 11th March 2006, 13:49

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 · 12th April 2006, 21:24

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 · 12th April 2006, 21:38

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 · 12th April 2006, 22:03

Forgive me if I missed something but I can't see the delay value.

Quote:

Originally Posted by mikemcc

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 · 3rd May 2006, 13:56

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 · 20th June 2006, 23:11

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

10th March 2006, 01:20	#1 \| Link
mikemcc Registered User Join Date: Mar 2005 Location: London Posts: 4	Audio delay / lip sync 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.

11th March 2006, 05:25	#2 \| Link
plomon 123kid Join Date: Aug 2005 Location: India Posts: 47	rip a small part of audio using Rejig(download here). it tells you the audio delay in it's file name itself. __________________ Have a nice day !!! :cool:

12th April 2006, 21:38	#5 \| Link
mikemcc Registered User Join Date: Mar 2005 Location: London Posts: 4	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. Last edited by mikemcc; 12th April 2006 at 21:41.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

11th March 2006, 13:49	#3 \| Link
mikemcc Registered User Join Date: Mar 2005 Location: London Posts: 4	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.

12th April 2006, 21:24	#4 \| Link
j7n Registered User Join Date: Apr 2006 Posts: 101	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?

3rd May 2006, 13:56	#7 \| Link
mikemcc Registered User Join Date: Mar 2005 Location: London Posts: 4	Sorry not to get back sooner. In ReJig: Select file mode, add Select VOB with audio, done See the audio delay Hope that helps

20th June 2006, 23:11	#8 \| Link
j7n Registered User Join Date: Apr 2006 Posts: 101	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