best way to fix audio sync?

[sad_luke]

Hi
I have saved a wav file from a avi file in virtualdub. When I try to make (S)VCD in Tmpgenc the audio is out of sync about 2 sec thru the whole movie. My question is what tool is the best one to fix sync, and the easiest since I´m kind of a newbie?
Any ideas?

Sad Luke

[thesicilian]

Does the avi play in sync?

[Don2050]

You can either use:

1. Virtualdub > Audio > Interleave. Adjust +/- Audio Skew in milliseconds to correct.

2. TMPGenc > Settings > Advanced > Source Range > Audio Gap. +/- in milliseconds to correct.

[spidey]

If you have access to Adobe Premier, or Sonic FOundry Vegas Video, if you have synch issue you can drag both the video and audio tracks into them.

Line it up, by seperating the tracks and manipulating them, and previewing them till they're in synch. Look for punctual things to help, gunshots, a door shutting, etc.

Then you re-render out the audio track only, but only the protions that are under the video timeline (including any silence), and then re-mp2 it, and multiplex it into your Mpg, replacing the old audio.

[sad_luke]

The avi is in sync.
Will try the things you guys wrote down.
I´m only having stuff that you can download as share/freeware, no Premiere or other things like that

[legionpc]

Are you splitting the video/audio into multiple parts on Vdub? i find that if I cut my video, the first section works fine, but at the beginning of the second part there is audio missing for some reason, and thus it is out of sync. So I started cutting the audio seperately in goldwave, and my sync problems vanished.

[Don2050]

legionPC,

Does the second video synch issue still occur if the video is cut on a keyframe ?

I ask cause I am trying to figure this out also.

thanks

[sad_luke]

The sound is out of sync even before I cut it

[Don2050]

Sad_luke,

Then use the TMPGEnc audio gap correct when you encode the avi. Do only 2 minutes or so at a time of a place that you notice the synch problem so you can figure out the correct setting.

So....load the avi into TMPGEnc then set the settings how you like, then go to the 'Audio Gap' correct section that I put above and adjust positively if the aduio plays to early and negatively if it plays to late. Use 100ms intervals untill you get right on......

Then once you know the right setting encode the whole thing with the exact audio gap adjustment.

[legionpc]

legionPC,

Does the second video synch issue still occur if the video is cut on a keyframe ?

I ask cause I am trying to figure this out also.

thanks

Yes, I always cut my files on a keyframe. No matter where I cut, on files with VBR audio, the second half is out of sync. So I simply go to the start frame for the second part, and note what position in the movie it is (eg: 54:16.095) then open goldwave, set a marker to start at that point, finish at the end of the audio, then save the selection to wav. That gives me a perfect cut of the second part of the audio.

[sad_luke]

Hi
I changed the settings from vdr to cbr and suddenly the sync is perfect. Don´t know how or why, but i´m just glad it is. Thanks to all of you who was helping out