Originally posted by: Belbucus
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is there anyway to identify an exact start point relative the video for synch purposes?

When you ripped the AC-3 off the DVD, you will probably have noticed it had a delay value specified.

Now, as far as I know you cannot specify a delay for PCM audio when authoring a DVD. So, if you take into account this delay by either padding the start with silence, or trimming a few milliseconds from the begining of the file, you will end up with audio that will line up with the video without any modification required by the end user.