How to Adjust Audio/Video Sync In An AVI File Using VirtualDub

Thanks for the info! Very helpful!

cant get that info to work my audio is still miles ahead of video

What is the differenct between doing this and re-encoding? Would re-encoding be a more proper way of doing it? If so how would I go about re-encoding? Thanks jd

Re-encoding means less quality and more time. Here you don't need re-encoding because you do not need to write either the audio nor the video stream, it's more like re-aligning the two streams.

thanks for the quick reply and excellent tutorial.

This has been extremely helpful, I've got a couple though that are out of sync but they get progressively worse. Any pointers on how to straighten that out?

Trial and error, sometimes it's not very easy to adjust the sync in one shot.

You have missed out the step before this where you find out what the delay is. http://polybore.blogspot.com/2008/05/avi-file-sound-out-of-sync-with-video.html Includes video tutorial.

Thanks for the help. I also used the link Polybore gave, but had a more complicated audio drift (worse as time goes on). Solution: 1. use virtualdub to save the audio and video separately. 2. use 'super' to convert the audio from mp3 to wav. 3. use "Wavefile Length Adjust" to stretch the audio to the same length as the video (virtualdub tells you both durations and you give them as a ratio to WLA.) 4. use 'super' to convert the wav back to mp3. 5. use "AVI-Mux" to put the video back together!

Thanks for this and especially for Polybore's tutorial for determining the exact value for the delay. Saved me tons of grief!

Thanks, worked perfectly first time. I found out the video delay (1sec 109ms) with the free "MediaInfo" program, then used your tutorial. Perfect sync first time! Thanks again.

hello, Im trying to sync audio to a video, but the audio i am using is about 5 minutes longer than the video, so what do i do?

Hey mine was of by (15100 MS) hope that helps it was an error with my spliting program though and i lost the first bit of sound vertual dub has all the glory

Thanks for the great tutorial. Very useful. I followed the steps and it worked perfectly.

Very good tutorial! I am digitising a batch of Hi8 Camcorder tapes and have bad out of synch A/V. I like the power of VirtuaDub but I don't understand why I never get out of synch A/V using Ulead VideoStudio but invariably get it with VirtualDub. Can someone please help with a question? The tutorial suggests that both Video and Audio must be set to Direct stream mode. But that disables processing, and with these videos I definitely need to use the de-interlace filter, which of course needs processing mode. Do I run one pass using Direct stream to re-synch the audio, and then another pass in Proessing mode to use the de-interlace filter? Or is there a better way to do it? Many thanks.

really helpful.........

ohh my gosh, thank you soo much for posting this i have tried this and it works.I had a video that i had to put off because the audio and the video were out of sync. Now i have learned something new.

OK, I have a video capture where the audio goes out of sync in the middle after an encoding error. Can this be fixed? I don't want to save it until I am sure that the A/V is in sync after that point. again, can that be done?

@leonm54, If your audio is in sync for part of the movie, then goes out of sync for the remainder (and the out of sync is constant), then use VirtualDub to first divide the video into two parts, saving the first part as one file and the out of sync part as another. The open the out of sync part in VDub and adjust the sync and save it again. Then open the first part, use the Append option, and add the now-synced second part to join them up again. You'll want to make sure that Direct Stream Copy is selected for both Audio and Video.

What about when the audio is going faster or slower then the video? Someone offered a PREPOSTEROUS solution of removing the audio from the video. changing the speed that way, then putting it back in. (Oh yah that will only make trial and error take 300 years). Virtual dub can change the freq of the audio right?

finally,, somebody who knows what he's talkin about... thanks man!!

Thank you very much. it works really good.

Great, it worked for me. I'm converting some programs recorded from terrestrial digital (DVB-T, MPEG-2) into DivX video and MP3 audio. Correct value I've computed is -550ms.

No good: I have an AVI movie in which audio is approx 7 sec ahead of the video and when I tried the VirtualDub I got an error that it COULD NOT FIND A DECOMPRESSOR FOR FORMAT XVID. But this is just an ordinary AVI file.

@li: Nothing is called ordinary AVI file, Avi is a container format for a codec which is XVID in your case

How do you find out the EXACT ms delay? I did read you could use a program called GSPOT. But having done that, could anyone tell me where in the program it tells you the exact delay between the audio and video?

@Ivan: I do not think there is a program can tell you that, just use your stop watch and trial and error to get as good results as possible.

Thanks a lot. It worked.

very helpful, man!

This didnt work for me! first of all: The delay rate suggested by VirtualDub and by MediaInfo is wrong. Its almost three times the rate. If I type it in it the way you show here it works only for the first few second. Then the audio is out of sync again. Whats going on?

Ok, my problem is that half way through the movie the audio goes out by 800ms,first half is fine but 2nd half out of sync to the end of the movie, how do i split and adjust the audio where needed using vdub? thanx in advance for any help.

THANK YOU VERY MUCH KIND SIR!! Very helpful indeed.

Sometimes the delay is not fixed for the whole length of the movie, in this case I usually split the movie using Direct Stream Copy for audio and video, apply the audio/video sync and then join it again.

Im having problems playing the audio back on Ps3 it sync s fine but cant hear anything

@Richard,Pleas make sure you have done step (4) "Video -> Direct stream copy and Audio -> Direct stream copy" this should make sure you don't change the encoding so if the original file plays fine, the modified one should too.

Thanks for info,Works great.

Thank you so much, this worked with my MKV file. I spent nearly 5 hours encoding it using Divx, to later find out it was out of sync. I was really hoping I wouldn't have to re-encode, and this fixed the problem. I had to spit the clips tho, then rejoin them using another software. But faster than re-encoding. Thanks!

Excellent tutorial, you're the man!!!!!

thanks man, really thanks :D