what codec is used during the capture process?

I’ve been burning DVDs from miniDV source shot with my digital camcorder . I’m capturing MPEG2 video, cutting out the unwanted portions, and then burning my DVDs.

When “capturing” the DV video from my camcorder, is a CODEC involved in the “capture” process? Or, is the video already compressed on my mini-DV tape and therefore just transfered onto my PC’s hard drive? If there IS a CODEC used during the capture process, how can I tell which one is used? And would it be determined by my camcorder (Sony DCR-TRV30), the capture card (OHCI compliant, but unbranded), or the software I’m using to perform the capture (Ulead Video Studio 7)?

I’ve also been converting some of my old VHS tapes to DVD ... using the camcorder to digitize the analog output signal from the VCR on-the-fly. I just connect the VCR output to the camcorder input jacks, and then connect the camcorder output (via firewire) to the PC. Then, in Video Studio, the capture process works just about the same way as when I’m just capturing the DV video. Would a CODEC be used in this case? Would it be on the PC or a hardware-based CODEC built-into the camcorder?

The reason I need to know all this is because I’m having audio/video sync issues when capturing the video from VHS tapes. For each hour, my audio gets about one second ahead of the video. That’s not too big of a problem for a 30 minute clip, but it’s a BIG problem for 2 hour or longer VHS tapes. And I’m taking all the normal precautions like shutting down anti-virus software, etc. before doing the capture. And my mobo is fast, lots of memory, P4 2.5 Ghz CPU, etc. And all my drivers are up to date ... except maybe the CODECs, which is why I’m trying to figure out how/if they are used.

Thanks for your help,
Adam