How do you sync words and lip movement?
by Dawn
(Baltimore,MD)
Question: I have a movie where towards the end the lip movement and voice is not in sync. Do you know how I can correct this?
Answer: Hi Dawn, thanks for your interesting question. I'll do my best to answer it.
First of all, this issue you detected is due to the video and audio tracks in the video being out of synch. This is also known in the industry as "lip synch error". It can be very disruptive to your viewers.
There are in general two simple causes of lip synch error. The first possibility is that the audio track is offset from the video track from the start of the video. This would cause the synch error to be the same throughout the video.
The other possibility is that the audio and video track length are different. This would cause the lip synch error to gradually get worse during the video.
These problems can also be caused by errors or missing video or audio. To make it more complicated, you can have a combination of all of these.
If you have tried playing the video file in different players and still see the problem, then it is a problem with the video file and not the video player. If you find it works in one player but not another, then the problem could be related to your player.
Synch errors during playback can be caused by problems with the disc or problems with the player. Sometimes, if you fast forward or reverse too much, the queue can lose too much data. Most video players should pick up and re-sync in a few seconds of regular play. An inferior video player might be unable to do this, causing a synch error.
Now, having understood that, how do you correct your problem? Well, if you have access to the original video file, you can attempt to correct it.
Most video editing software offers audio syncing tools. Sony Vegas, Adobe Premiere Pro, Avid and Apple's Final Cut Pro allow easy audio syncing. The syncing is done by isolating the audio from the video track and repositioning the audio correctly on the time line. Perfect audio syncing takes practice, but it is not difficult to master.
Here's what you need to do. I've assumed you're talking about an AVI file here.
- Step 1. Open your video editing software of choice. Adobe Premiere Pro or Sony Vegas are both easy to use and offer free software trials. Import the AVI file into the timeline by dragging the file into the program or by selecting "File" and "Import".
- Step 2. Right click on the audio track of the video, and click "Unlink" to unlock the audio track and allow the audio to be moved along the time line. Watch the video to determine how far off the sync is. Is the audio ahead of or behind the video? Zoom in on the time line to troubleshoot the audio more accurately.
- Step 3. Grab the audio track and adjust it relative to how it is out of sync. Play the video after adjusting the audio track to see if you fixed the sync problem. Keep adjusting the audio track until the sound matches the video. Zoom in on the time line to adjust the audio more accurately. Once you have synced the sound, render the video and you should be done.
I hope the above helps you out, Dawn. Feel free to contact me if you need more assistance.
