Audio Sync Issues - Can't find resolution!

[cl0nd0n]

Hi all.

I have been searching the forum for a while now, already attempted some of the obvious stuff but no matter what I do I am having issues with my avi to dvd conversions.

Basically the audio looses sync progressivly over the video. I have got the size ratios sorted etc using the quicktime encoding but can't get the audio right. It always seems to be 3 or 4 seconds ahead of the movie?

This is the info from quicktime / vlc on the original avi :





These are the settings I am using in ffmpeg :








Can someone help me shed some light on this. I have about a dozen avi movies I wish to burn to DVD and so far cannot find anyway to get the audio right!

Thanks in advance.

[Case]

Do try the DVD mpeg2enc preset as Target format, also with Decode with QuickTime. And include the Set 3:2 checkbox.
Also change the folder name to something without spaces, as some modules in ffmpegX may trip over that. (You may have gotten away with it with DVD ffmpeg, but DVD mpeg2enc is not the same module.)

[cl0nd0n]

Do try the DVD mpeg2enc preset as Target format, also with Decode with QuickTime. And include the Set 3:2 checkbox.
Also change the folder name to something without spaces, as some modules in ffmpegX may trip over that. (You may have gotten away with it with DVD ffmpeg, but DVD mpeg2enc is not the same module.)

Case

Thanks for the response but I have tried mpeg2enc with no sucess. I will give it a go removing the spaces in the title but I am not sure this would affect the audio sync so badly!

Any other ideas?

Thanks

[Case]

True, spaces and special characters will not affect the sync. It may however stop certain processes, resulting in a failed or incomplete conversion.

Your source file may have stretched audio or some other audio or video issues that may hinder a synced conversion.

I would use the video part from the ffmpegX conversion (.m2v) and use a QuickTime Pro export of the audio (.wav), hoping that they are the same length time-wise, and hoping that they sync up.
If that doesn't work, it could be a lot of adjustments to make it work.

[tomlee59]

I encounter this problem in about 20% of the conversions I do. Mpeg2enc may have a bug; it seems to be fooled by at least two things:

1) Scene breaks that have an extended blank interval. This causes discontinuous sync jumps.
2) Alternating frame rates (some films are authored with a mixture of 24fps and 30fps content). This can cause gradually worsening sync.

If you experience a more or less steadily increasing error, then you may be able to fix things by carefully noting the sync error at the beginning, middle and end, and using a tool such as Audacity (free!) to stretch/shorten the audio track as needed to match things up. A combination of muxing offset and such stretching/shortening can often fix this.

Jumps in sync caused by the scene changes can't be fixed this way -- you'll need to sync each segment separately and recombine. Hopefully, you won't have to do this.

In any case, I've never been able to find a way to avoid this problem, so this kludge method is the best I've come up with.

Hopefully, someone will jump in with a cleaner solution (so I can use it!), but this is all I've been able to devise so far.