why Audio gets out of sync in long movies?

[hhamzeh]

Hi there,
I have read in several forums that if we capture long movies, the audio gets out of sync. Can somebody please explain why this happends? I Usually capture from my mini DV (both from DV tape and from VHS through my mini DV cam) by firewire. My movies are around one hour and I have not noticed any sync problem. Does this problem apply to certain formats? or if I capture about 2 hours I will get to this problem? Any suggestion how to provent this problem? Thanks

[ZippyP.]

Transfering your DV-format video via Firewire is not really capturing. It is merely a transfer of the digital information from your camera to the computer through the Firewire port.. In the case of your VHS copying, your camera is doing the capture. Capture in the usual sense is analog signals being converted and saved into digital form by some sort of capture device like a card or box. I think it's during those analog to digital transforms that people are seeing sync problems, especially on longer captures. You probably will have less of a problem, if any.

[hhamzeh]

So, does it mean that A/V sync problem does not apply to transfering from Digital camcorder (play back a Digital tape) to computer through firewire no matter how long the movie is?

[ZippyP.]

In theory you shouldn't get any problems, in practice......well maybe someone who has more experience with DV transfer can answer.

[spiderman2k1]

I have tried the ATI AIW if VHS its very good. But is does not like macrovision. i use a SIMA copymaster and still have problem's with the old software I have no problem's MMC 7.1 I cap at MPEg 1 then encode with TMPG. Some one on www.dazzlegeek.com made a post saying that the Canopus MPEGPRO EMR has no problem's with the worst VHS tape's there a USB and pci version of this card. Read this post http://www.dazzlegeek.com/viewtopic.php?t=2964