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Controlling field dominance
I continue to have an issue in Final Cut, using BlackMagic cards, where, if I put a source clip of one field dominance into a sequence of the other field dominance, someone (I assume FCP) automatically adds the Shift Fields filter.
With my hardware configuration i.e. FCP with BlackMagic card, this filter is not necessary, and I have to remove it.First assumption is, BlackMagic hardware will handle the changing of field dominance? If so, I like that kind of ‘smarts’.
Second assumption is, FCP sees the difference between a source’s dominance and a sequence’s dominance and adds the Shift Fields filter? if so, Apple needs to make it a user-switchable item, so we can determine who runs the ship.If I’m right in both assumptions, then the two (FCP & BlackMagic) are conflicting.
Can someone(s) please shed some light on this?
cheers.
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17 Replies
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What codecs are you using?
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Well the BlackMagic codecs are installed, as part of their software installation, but in FCP, the effect handling is set, as recommeded by BlackMagic Design, to Final Cut Pro.
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I meant, what codecs/formats/frame rate are you going to and from to need the use of the shift fields filter? Are you going from Pal to NTSC or vice versa?
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“Are you going from Pal to NTSC or vice versa?”
Firstly, its a PAL system.
Secondly, the scenario varies, but take this one as an example:
cutting DV-Pal (lower field) footage into a 10bit (upper field)Sequence … -
That’s what I thought. You are over thinking this. If you are in a PAL Upper field (uncompressed) sequence and you put a PAL dv clip in, FCP puts the shift fields filter because it is conforming the DV (lower field) clip to upper field. Then the BlackMagic card outputs upper field first. The Blackmagic card does not know when or where the DV PAL clip is coming in the timeline so it can’t possibly shift the fields for you. It just outputs upper field first for a PAL uncompressed sequence.
Make sense? FCP does this so that the field order will be the same throughout the timeline. If the shift fields filter didn’t exist and the DV PAL clip was playing it would look funky as the field order would be wrong.
Jeremy
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No Jeremy,
what you describe is actually the problem.
BM WILL handle both field dominances in ONE sequence and play them correctly; it doesn’t need the Shift Fields filter.
But FCP adds it, because normally it WOULD need to, but, I assume, it doesn’t recognise that there is BM hardware onboard, and that IT will handle the shifting of fields.
So I’ve got a conflict between BM and FCP BOTH trying to handle the issue, and in turn, creating the very problem we are trying to prevent or fix!To be clear, with a Decklink card, FCP DOESN’t need a Shift Fields filter in order to play fields correctly!
I DO get the inverted fields jitter if I leave the Shift Fields filter on … -
Send feedback to Apple. You are totally screwed. or you could just delete the shift fields filter, or better yet capture everything in the same codec.
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“You are totally screwed”
Am I the only one with this issue ?!?!?!?!?!?!?!?
But thanks for the advice, Jeremy; I will seek a solution elsewhere.
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How do you know the Bm card does this? how did you capture your footage?
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“how did you capture your footage?”
Yes.
We have two FCP edit suites, each with a Decklink card (although two different cards.)
We capture in various codecs, depending on the source material, mostly from broadcast decks.
BM is capturing everything properly.
DV codecs are all captured correctly as lower field, all others as upper.We are not doing anything obscure or unusual.
I just think, as I said originally, that FCP and BM are both trying to solve an issue at the same time, thereby leaving with the problem that they are trying to avoid.BTW, I posted this on the BlackMagic forum but no-one offered a solution, only one response from someone with the same issue.
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