SYNC TROUBLES - HELP!!

spike_spiegel wrote on 6/3/2003, 12:28 PM

Can anybody tell me why I am seeing sync issues (i.e. - Japanese monster-movie syndrome) with DVD's produced using V4 and DVDA, that DO NOT (I emphasize they do not) appear when viewed on a standard TV/DVD player set-up, but when I screen on a venue-sized (LCD) projector and play through the house sound board, I get bad sync.

I don't think it is a signal lag issue, because the problem also does NOT appear to be there in any "commercial" DVDs (i.e. - rented from Blockbuster). At least, if it is there, it is too small an effect to notice.

Everything is so new, I have not tested anything that was front-to-back native 60i (the projects I did so far were all shot 24p) and I realize that could be the source of the problem, but WHY wouldn't it show on a regular TV?

I am confused! My head hurts! And there are so many bounties to chase!

- Spike

Comments

SonyDennis wrote on 6/3/2003, 1:17 PM

Spike:

I've always wondered how long it will take the A/V industry to come up with sync adjustment settings. When you add (say) a line-doubler (with pulldown removal) in front of an LCD projector, by definition, it adds a few field-times worth of delay before it sends out the image. The LCD projector probably has a field delay or two. These all add up, and if you don't have a way of compensating on the audio side, you're out of sync.

That said, you mentioned that you don't see this sync problem with commercial DVDs.

Are you aware that with the Panansonic DVX100, audio leads video by about 1 frame in 24p mode? If your projector system was already on the perceivable edge of audio lead, this extra frame could push it into Monster Movie Mode.

///d@