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How to Fix Audio-Video Sync Problems in MPEG Files

Unfortunately not all conversions go 100% smoothly and some result in the Audio and Video out of

synchronization. This can be due to many reasons with the primary problems being the original movie source

and software/codec clashes. Here I will tell you how to fix these problems with just a few clicks.

Tools needed: WOMBLE MPEG Video Wizard DVD

This software provides three tools ( three methods )  to solve your audio/video sync problem.

a):MPEG GOP Fixer

This tool lets you check and correct GOP time code errors, video and audio PTS (presentation time stamp)

errors, and DVD GOP size violations, which may be present in an MPEG data file.

1. Click the tools button on the Toolbar, and select MPEG GOP Fixer in the drop-down list.

2. In the open dialog window, input your problematical MPEG file.

3. Then, in the "Test Options", you can choose one solution to deal with your file. e.g. "Fix GOP time

code and PTS errors (Read + Write)" , and then "Start". The GOP Fixer will automatically scan your MPEG

files and fix the errors.

b): MPEG MBS Scanner

There may occur audio/video sync problem when one MPEG file contains one of the three changes below:

Timebase change, such as a time code restart;

Video encoder settings change, such as image size, frame rate, and bit rate; and

Audio encoder settings change, such as sampling frequency, bit rate, and number of sound channels.

We refer this kind of file as a Multiple Bit Stream (MBS) MPEG file . When this occurs, we can fix this

a/v sync problem by using MPEG MBS Scanner.

1. To open MPEG MBS Scanner, click on the Toolbar and select MPEG MBS Scanner from the list.

2. In the open dialog window, input your problematical MPEG file, then click "Scan" to start finding the

errors.

3. After finishing the scanner process, you can add the list of segment files to timeline or project

manager for further edit. e.g. "Add to Timeline".

4. Export to a new MPEG file.

c): MPEG DeMultiplexer

Use this tool to split an MPEG Systems stream into a set of elementary streams (video-only and audio-only

streams). It is very efficient to help you resolve the audio/video synchronization problem, as frequently

encountered in MPEG files with time code errors.

1. Click the tools button on the Toolbar, and select MPEG DeMultiplexer in the drop-down list.

2. In the open dialog window, input your problematical MPEG file, and check the box "Create a new project

on the Timeline with the output files" for further editing.

3. Split the MPEG System file into separate video and audio files by clicking on "Save". The separate

video (.mpv) and audio (.mpa) will automatically be imported onto timeline after finishing the demuxing

process.

4. Adjust the relative offset between audio and video, by moving either the video clip or the audio clip,

till they are in sync.

5. Save the result to a new MPEG file.

Click here to download WOMBLE MPEG Video Wizard DVD

About the Author

A computer freak

What digital camera has the best video, audio?

Our friends are opening for Aaron Tippen in 2 weeks. Would love to get a camera with great audio/video options. Any ideas out there?

I think MiniDV cameras are nice. I have a Panasonic camera (3DGP?) with a Leica Lens. Check around to see if they're all "HD" these days, I think mine is "standard def". However, I made a tape for friends of mine and they were blown away at it's clarity. For sound, always use an external mic when possible. If you are at a loud concert, be sure to find out how to turn the sound all the way down and use AGC (Automatic Gain Control). (Be sure to turn the mic back up when the show is over!) Use bestbuy.com and bhphotovideo.com to shop.