Why does audio lose sync with video when capturing from VCR?

[leecotton]

Anyone got any idea why this would be? I'm capturing from a VCR using the Adaptec AVC 2210. After about 45 mins, the audio slowly starts to slip behind the video, getting worse the longer the recording, until they're so out of sync it's useless. The strange thing is that capturing other sources with the same box (live TV, Digital TV recordings) never do this, only the VCR source. Can anyone give any ideas why this may be?

Lee.

[Capmaster]

Anyone got any idea why this would be? I'm capturing from a VCR using the Adaptec AVC 2210. After about 45 mins, the audio slowly starts to slip behind the video, getting worse the longer the recording, until they're so out of sync it's useless. The strange thing is that capturing other sources with the same box (live TV, Digital TV recordings) never do this, only the VCR source. Can anyone give any ideas why this may be?

Lee.

Probably because you're capturing off tape. You don't mention if you're using a timebase corrector, so I'm assuming you're not.

That would be a good place to start. I had the same problem with my VHS caps until I bought one

[luigi2000]

Does your capture device interface indicate when frames have been dropped? When audio is about three frames out of synchronization it is noticeable to the casual viewer. The proper way for an analog source to be captured is to resample the audio during capture in order to maintain synchronization with the video. VirtualVCR and VirtualDub MPEG resample the audio when using a VIVO video card for capturing.

[lordsmurf]

Read the stickies:
https://www.videohelp.com/forum/viewtopic.php?t=166660

[leecotton]

Thanks for all the info chaps. I'm not using a timebase corrector and I don't believe my VCR does this on it's own. I'll check it out, plus the Virtualdub thingy.

Thanks a lot!