video and audio sync problems with HD

siegeld wrote on 1/28/2006, 7:23 AM
I am editing HDV content (M2T format) from a Sony HC1. I use Vegas 6 to convert the raw content from the camcorder to Windows Media Video HD. I've done a few conversions and the output was fine - quality great, audio and video in perfect sync. Unfortunately, on my latest raw M2T video, the HC1 had a dropout. This is the typical 1/2 second loss of video. When rendering this to Windows Media HD from Vegas, the audio and video loose sync at exactly the point of the dropout, and from that point forward. The raw M2T content does not go out of sync. If I just view that, after the dropout, all resumes just fine.

So - what's going on? I assume this is some sort of bug with Vegas, right? I can't figure out a workaround except from carefully trying to find all the dropouts and then editing them out. I've tried to contact Sony Media via their web response site, but no one ever gets back to me.

Also - I tried editing out the dropout to see if I could fix the sync issue, and no luck. In fact, it is even worse. Every time I introduce an edit in the MT2 stream, I create a sync problem! That is, if I take a perfectly fine segment of the original m2t video, cut out a segment, and then render to Windows Media Video, I get a sync problem at the initial edit point!

Comments

Laurence wrote on 1/28/2006, 7:45 AM
I would fix offending M2T into MPEG Wizard from womble,com. MPEG Wizard is a kind of basic mpeg editer that is really handy for editing mpegs without rerendering. It has one video track, one titling track and two audio tracks, one for music, one for voice overs. Anyway, put the offending M2T on the video track. Control drag it down to the music track. Right click on the video track and mute the audio so that the copy is all you hear. On the music track, split the track where it gets out of sync and drag the second half so that it lines up with the dialog. Render and your done. The new file will be bit copied rather than rendered and not lose quality. Such occurences are rare, but they do happen from time to time.