.avi file with sound out of synch

[fpb]

I have a long .avi file where the soundtrack is a few seconds out of synch with the images, so that the characters are heard to have spoken before their mouths move. Is there anything I can do to change that?

Comments

[inverarity.livejournal.com]

There are free/shareware AVI editors available, but the last time I checked, they weren't necessarily very user friendly, so you'll probably have to spend some time figuring out how to slice and dice your avi file.

[panobjecticon.livejournal.com]

there's a program called avidemux, which is apparently very good, but as inverarity says the programs can be difficult to use and, worse still, i understand that if the sampling and bitrates are variable, it can become a bit of a nightmare. i'd use windows media encoder to convert avi to wmv, audacity to create a new sound file and then edit using windows movie maker - mute the original and overlay the new one. there's probably a simple program if you want to pay for it. good luck...

[mentalguy.livejournal.com]

Well. If you use VLC as a media player (which I highly recommend), it has an option to adjust the audio/video sync during playback. (Tools|Track Synchronization, from the menu)

Actually editing the .avi to fix the synchronization is can be extremely frustrating and fiddly, as any sort of video editing or transcoding tends to be. Working with video is something of a black art.

You could certainly make a go of it with avidemux, since adjusting the relative timing of the audio and video tracks is a relatively simple operation, but it may or may not turn out to be easy depending on how the original .avi file was produced.

[shezan.livejournal.com]

Can't recommend VLC enough.

[evil-whimsey.livejournal.com]

Using the VLC sync adjustment, as mentioned in the thread above, is probably the easiest solution. Aside from that, you'd be looking at using an encoding tool to split the audio from the video track, manually re-align the audio and video tracks on an edit timeline, and then re-export the file.

Note that this assumes the audio is playing out of sync from the beginning of the avi file. If the avi starts in sync, and gradually goes out, then the problem is likely due to an incompatibility between the video and audio bitrates or framerates, and is considerably more complicated to fix.

If you're interested in rolling up your sleeves and having a go at fixing the file, there's a relatively simple tool I like, called Virtual Dub, which is handy for these kinds of operations. Also, the forums over on Doom9 are an outstanding educational resource.