Converting AVI to xvid AVI - Audio Sync Problem

[foochuck]

I'm using AutoGK to convert my DV AVI file to an xvid AVI file.

After I view my final xvid AVI file, the video and audio are out of sync and I can't figure out how to fix this.

1. I have checked my original AVI and the audio and video ARE synced up.

2. I would like to figure out what I'm doing wrong so this process is only one step and so I don't have to fix the outputted xvid AVI everytime I go through this conversion.

Any suggestions?

I can not tell if the audio sync is changing from the beginning through the ending of my file ( It's hour long ) but I know that right off the bat the sync is definitly off.

Thanks

[redwudz]

Open it in a program like VirtualDub or VDM and in 'File>File information' check the lengths of the audio and video. If the video has the same sync error throughout, you can add a offset in VD to correct it. In VDM, 'Streams>Stream list'. R click on the audio file>Interleaving. Add your audio skew correction in milliseconds. The hard part is determining how much.

If the video gradually goes out of sync, the video and audio lengths may be different. You will need to adjust one or the other. The audio is usually easier.

But it's better and much easier to determine why it would be out of sync in the first place. It may have missing or corrupted video frames or missing audio. This can happen with bad joins or a corrupted file. Or bad conversions from VBR audio.

[foochuck]

Alright I have checked the video and audio lengths, they are:

video: (59:18:99)

audio: (59:18.98 )

How do I determine if the video has the same sync error throughout?

I'm using Virtualdub.

Also, how do I add an offset in VD? If I add an offset and preview the video in VD, will it update with the offset I applied or do I have to resave the video file?

[redwudz]

To determine if the sync error is changing, just watch the video or check the sync at the beginning and near the end.

To adjust the skew in VD Mod: Streams>Stream list>R click on the audio file>Interleaving>Audio skew correction. It's in milliseconds, + or -. You need to determine the offset error. You can play the video back with MPC and adjust the sync there, then use that number in VDM or VD.

In VD, 'Audio>Interleaving' then the same as above.

You can use 'Preview' to check it.

You can save both the audio and video with 'Direct stream copy', so it shouldn't take long.