Audio synch problem extracting clip from MF4-created file

macwino · Post by **macwino** » Mon Jun 20, 2005 9:15 pm

I am using MF4. I have a video contained in a DVD folder that was created with MF4. When I import this DVD folder into MF4 to do some further editing, the audio is in synch with the video, as it should be.

However, when I try and edit a small portion of the video and save it as a new DVD folder the audio for this small portion is out of synch. I can't seem to figure out why. As a result, if I have an hour long video in a DVD folder, and want to use just 10 minutes of it, I can't because the audio for this portion will be out of synch when I clip it from the original.

My audio settings have not been changed at all during this process. In creating the clip they are identical to what they were when the original DVD folder was created. So why is the original video in synch with the audio, but when I remove a clip from it the audio for the clip is out of synch?

Thanks for any input.

A possible solution might be to use Video Studio to resynch the audio. But my review of the manual for this program makes no mention of any such capability. In any case, I don't think MF4 should be messing up the audio as it now is.

macwino · Post by **macwino** » Tue Jun 21, 2005 2:08 am

Since posting I tried a few more solutions but none solve the problem. I tried saving the clip as an iso file instead of a DVD folder. The audio is still out of synch. I also tried to bring the original DVD folder, which has good audio, into MF3 to see if it would keep the audio in synch. A clip made within MF3, however, was even more out of synch than one made with MF4.

I hope someone has some thoughts on this because I'd hate to think that I can't use this video except in its full, unedited state.

Thanks. Robert

maddrummer3301 · Post by **maddrummer3301** » Tue Jun 21, 2005 4:01 am

The mpg2 file being re-created is the problem.
It can play in sync on the timeline or in a software player but when put
into a VOB container will be out-of-sync.

You could try exporting the video after editing it by clicking on the
icons on the left of the screen while on the timeline.
There are a few outputting options when doing this.

Also, under the "Preferences" (F6) there is an option to create
an index file (Preferences -> Advanced) {Create an index file for MPEG seeking performance).
That option may work if MF4 created the DVD. I would think that is what that
option is for. I thought I read where it helps keeping the audio in sync but
I'm not sure about that.

You could also try VideoStudio9 to edit the video.
Remember though that VS9 doesn't support dolby audio in the trial version.

The biggest headache is it takes a good deal of time to edit the video,
render it and burn to dvd. Then find out it's out-of-sync.

MD

rdsatkaycee · Post by **rdsatkaycee** » Tue Jun 21, 2005 1:03 pm

Madrunner, are you saying then that if we don't use Mpeg2 there will not be a synchronization problem? If not, then what? Thanks

macwino · Post by **macwino** » Tue Jun 21, 2005 4:32 pm

I tried some of Madrunner's suggestions but still no luck.

The main mpg file has the audio in synch. If I take a contiguous clip from this main file and export it as an mpg file using the buttons on the left of the timeline (which I was unaware of and am grateful to Madrunner for pointing out to me) I get an mpg file of just the clip. Its audio is in synch. Then, if I bring this mpg clip back into MF4, edit out just a few seconds, and then create a DVD folder or iso file of the edited clip, the result is a file with the audio out of synch.

I've never had this happen before. I have edited dozens of master mpg files. What might it be about this particular mpg video that is giving it these strange characteristics? BTW, we aren't talking about any copy protected files, just in case that might be an issue.

Thanks for the input. I appreciate it. Robert