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View Full Version : How to multiplex + fix a sound lag - help rqd!


Trantor123
26th March 2005, 15:21
Hi,

This is my first post on these forums - first of all, I'd like to say hi to all the other members who seem very knowledgeable and willing to help.

Although I'm a fairly experienced DVD ripper and have been tinkering with audio and video for a while, something's got me stumped. I bought a DVD in the far east whilst on holiday and it has a problem with the audio track. There's a time lag of about a second between someone speaking on the video track and the soundtrack actually emitting what they said. As you can imagine, this is really annoying.

What I thought I could do is demux the audio and video streams, which I've done, and then import them into a video editor where I can manually shift the audio track left or right a bit until the lip-synch is perfectly back where it should be, and then multiplex or render the resulting stream back out to rebuild the DVD.

However, I don't have software to do this. I was hoping to use my trusty DVD Architect 4.0 but it won't let me import the .m2v or .ac3 streams. So, my question is whether anyone could recommend a software solution for me. I don't want to lose any quality here - I just want to shift the soundtrack to remove the lag, and then multiplex the two streams together.

Can it be done?

manono
27th March 2005, 07:21
Hello, and welcome to the forum-

First you have to determine the delay. I'd do it with Media Player Classic (https://sourceforge.net/project/showfiles.php?group_id=82303&release_id=314365). Open one of the vobs in it, and then right-click on the video and go Options->Audio Switcher->(check) Audio Time Shift (ms): and fool with the delay until you get one that looks good. Then I'd set that delay in AC3 Delay Corrector (http://home.t-online.de/home/520072193568-0001/). Then mux everything back together with your favorite authoring app (I use MuxMan), and reinsert the remuxed vobs back into the original DVD files using VobBlanker's "Replace" feature. That's one way, anyway.

Trantor123
27th March 2005, 10:35
Thanks a lot - sounds like a good solution. I'll give it a try today...