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VariCam sync problems in FCP
I can’t figure out if I’m doing something wrong, or this is “expected behavior” … from posts in the past, I think it might be the latter, but I want to double check.
We have:
MacPro 2×2.66 GHz, 4 GB RAM
Panasonic AJ-HD1400
Blackmagic Card (Decklink HD Extreme)
FCP 6.0.1We shot 720p, 25fps, are capturing through the Blackmagic with HD-SDI, and recompressing to a 720p60 25fps clip on the other side.
I’m noticing some sync variance in clips. It seems to range from 2 to 7 frames and varies from clip to clip (even within a tape). I read some issues about sync on the Varicam, but checking the tape, the sync seems to be fine (or at least not as obvious as 7 frames).
(I also ran into major sync issues on other tapes, until I figured out that one cameraman was changing frame rates during the capture. Now I monitor user bits during the capture, so I know that’s not the problem.)
Anyone have any suggestions? I have 100 tapes of event coverage for 88 minutes of programming so this is a major-major.
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12 Replies
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Could you be dropping frames- sounds like it(no pun intended).
Noah
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well, I have it set to abort capture on dropped frames … so that shouldn’t be the problem. Also, the sync problem seems (at least with a quick investigation) to be uniform across the clip, not accruing as the clip goes on. I suppose if all the frames are dropped at the start, though, that could be the problem?
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How fast are the hard drives? Have you captured 720p50 HD-SDI before with this setup?
-Noah
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I’ve been using the internal drives, 7200 rpm. We’ve filled up the internal bays, so we just added an eSata drive yesterday and I did some capturing to that as well. This is the first time I’ve used this set up (joys of freelance) and first time we’ve captured HD-SDI on it. (Although, we’re recompressing to DVCPRO 720p60, 25fps on the disk. It’s only HD-SDI from the deck to the BlackMagic card.)
But, yeah, this is the first time all of these elements have been combined in one system, it’s been a headache, and I have every reason to believe I’ve missed a tweak or optimal configuration along the way.
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Yup I’d go back to the internal for a capture and see what happens. Sounds like too slow a drive.
Noah
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Sorry, to clarify, a good chunk of the out of sync footage was captured to the internals. So if it’s a speed issue, it’s an issue with the internals as well.
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Could also be a driver issue with the Kona. Any chance you can just rent a 1200A deck and capture over Firewire- quality is identical.
Noah
Unlock the secrets of the DVX100, Apple Color and now the HVX200!
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If you capture via firewire, then you will be 2-7 frames out of sync. Typically I am 2 frames when I capture with my G5 (and yes, FAST 230MB/s Raid), and 7 frames off when I capture to my laptop (with a 140MB/s Raid). So it isn’t the drives, it is a firewire capture issue. I just slip the audio when I cut the footage into the timeline.
Now, when I capture with a Kona LH or Decklink Multibridge…then I am in sync. I use RS-422 deck control, capture HD SDI to the Kona or Decklink DVCPRO HD codec and sync is perfect. And the quality of the footage is identical, file sizes the same.
It is a firewire issue…
Shane
Littlefrog Post
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… except I’m not using Firewire, I’m using HD-SDI through BlackMagic. The tapes are captured now (we couldn’t wait any longer or afford to rent a different deck, if we could even find one available – not many in NZ) so it’s just going to be a manual sync for the project, which is a nightmare, but oh well. I suspect it’s something to do with 25 frame support for DVCPRO-HD.
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I have been having the same FCP 5 frame out/sync issues loading- HDX900 footage- through firewire, at HD (firewire) resolution onto external hardrives. I do not have a Kona Card and typically I have not had this problem- only with the 23.98 footage.
On another note…does anyone know the “correct shutter setting” for shooting HDX 900 1080 30fps. Is it “half” or actually the 1/60.3 which I had heard somewhere is correct. So it should give you normal looking lip-flap on interviews…
thanks
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