Z1: HDV captures are all 12 frames shorter than DV

NickHope wrote on 3/10/2008, 7:55 AM
I'm shooting 1080i50 on my Z1.

I set i.LINK CONV on and capture widescreen SD PAL DV from my Z1 to my clunky old laptop in the field using Scenalyzer and use this footage to make SD DVDs.

Back at the ranch I capture again, this time m2t HDV in HDV Split. I then do a bit of filename trickery, Gearshift my project, and smart render the best m2t clips to my stock archive.

The only problem is that recently the first 12 frames of the HDV captures are all missing. In other words the SD captures are all 12 frames longer. So when I Gearshift it's all wrong and any clips I hadn't shortened get 12 looped frames at the end.

Like HDVSplit, HDV captures in Vegas are also 12 frames shorter at the start then the SD capture (but they have those extra 3 frames at the end of each clip, which is another issue).

I've tried this with 3 different computers and various hard drives. I'm pretty sure this wasn't happening before (but possible I just never noticed because my workflow used to be different). 12 frames is quite a lot. Especially if it's a shark attack!

Any ideas why this might be happening and can it be fixed?

Comments

farss wrote on 3/10/2008, 8:22 AM
By any chance do you have the camera in Fast Record?
I think in that mode the Z1 doesn't close the GOP.

Either way as I recall from when Gearshift first came out it was said that capturing a DV downconvert and then capturing the HDV from the EDL just plain doesn't work. The precise technical reasons why I don't know but I'd hazard a guess the long GOP has something to do with it.

You might recover your missing frames if you capture with no scene detection, sure worth a try.
Bob.
NickHope wrote on 3/10/2008, 9:24 AM
QUICK REC doesn't affect it. I've just checked that out. By the way mine is turned OFF these days because of the anguish caused in post.

So I'm simply losing 12 frames at the start of every HDV clip.

Capturing without scene detection does recover the lost frames. That's a good idea if it's a critical clip. Thanks Bob.