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Jittery Motion on Clips
Hi All,
Sorry I’m new to this forum because I usually work on Windows, but my client is using FCP and we’re running into a problem with some footage supplied from them to us.Here’s the basic signal flow:
[CLIENT]
Capturing DVD via BlackMagic box into FCP using standard PAL DV 25fps settings. Interlaced and Upper Field First.Edited and Exported from FCP as 1920×1080 QT Interlaced (Animation Codec)
[ME]
I’ve taken the QT into AviSynth to resize back to PAL (Lagarith Lossless Codec)HC Encoder VBR 2-pass 7.5Mbps
Once burned to DVD, the video looks really good for the most part, but the client has said there are a few scenes that are very jittery, almost like the interlaced fields should be switched.
According to the client, these clips have been time adjusted in FCP. One is just reversed (-100%) and another has been slightly slowed to (98%)
Is this a known problem in FCP? If so, is there a way to fix on either my side or the client’s? None of these problems are present on any of the intermediate files, only on the DVD.
Many, many thanks for any help!
Clint
Adobe CS4 Master Suite
Vista Ultimate 64 SP1
Intel Core i7 920 @ 3.60GHz
12 GB DDR3 RAM
NVidia Quadro FX 3700
Matrox RT.X2 LE Capture Card
4 TB RAID 5 -
3 Replies
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Hi Clint
[Clint Milner] “Capturing DVD via BlackMagic box into FCP using standard PAL DV 25fps settings. Interlaced and Upper Field First. “
Oops … PAL DV is actually Lower Field First. Sounds like you have a fundamental field order mismatch. So long as nothing is “effected” (transitions, filters, speed changes etc) then you’d probably be fine, but those areas would be rebuilt during render using an incorrect field order, hence the jitter. Was this edit not monitored (during edit) on an interlaced display?
[Clint Milner] “None of these problems are present on any of the intermediate files, only on the DVD.”
How were these intermediate files viewed? Again, they’d have to be viewed properly on an interlaced monitor to see a field order issue, watching a progressive scan rendition (like in the FCP Canvas window) would not display the issue.
[Clint Milner] “is there a way to fix on either my side or the client’s?”
Well f this is indeed a field order issue then either yourself or (probably more easily) your client needs to fix the field order mismatch and re-render.
Hope it helps
Andy -
Hi Andy,
Thanks for the reply. I know that PAL DV footage is LFF, but for some reason when this footage is encoded to MPEG-2 as LFF, I get the traditional field jitter (including during the problem areas). UFF creates smooth video EXCEPT for these certain sections that have been time manipulated in FCP.
The source QT file from the client doesn’t show this jitter, but we can only check the file on computer screens, so it could be there I guess. I don’t think the client is editing with an Interlaced monitor.
The client and I are kind of at a stand still because neither of us know who’s at fault, but we both agree that the problem is during the footage that has been time adjusted.
I’m really hoping that you may have a couple more ideas up your sleeve, but thank you for your time.
Kind Regards,
ClintAdobe CS4 Master Suite
Vista Ultimate 64 SP1
Intel Core i7 920 @ 3.60GHz
12 GB DDR3 RAM
NVidia Quadro FX 3700
Matrox RT.X2 LE Capture Card
4 TB RAID 5 -
Hey Clint
In FCP, you just need to add the Shift Fields filter to the affected areas … that will reverse the field order in those sections, make it all buttery smooth again.
Your client can do it in his original timeline, or you can just razor it up and do it at your end.Give it a try
Andy
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