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720p 29.97 field dominance
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Hmm…well it’s tough to try and trouble shoot when you can’t do anything about it.
I would at the very least unload then reload the drivers and make sure you firmware is up to date with the latest drivers.
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When I hear from AJA, then I’ll see what their post supervisor wants to do. At the moment, this is all happening over the holidays and I’m the only one there. Plus it’s not holding me up. It’s mainly a nuisance when I bounce the footage out to SD and then ingest it back in as SD.
As far as your earlier question – yes, the SD is effectively 30PsF. It’s just that now, all progressive frames start on Field 2 of any interlaced frame. So all PsF frames are now F2/F1, etc. as you step through the media file or jog through it on a VTR. This means that if you attempt to make a trim on a previously-edited cut, you have to trim in an extra frame.
– Oliver
Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com -
Yeah, I understand the problem. I just don’t remember seeing it is all.
Sounds like a firmware issue to me, if I had to guess.
Jeremy
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What is the difference between field order vs field dominance? I guess I don’t understand this myself, but I have had the exact issues you are having (We were mixing ftg from 59.94, 23.98 and SD 29.97). I listed them below in another post. It was a pulldown issue, I’m sure. The way we fixed it was to trim an additional frame to get rid of a very sleight flash type frame that was happening due to an edit starting on the wrong field, I suppose.
Please let us know what AJA says if/when you find something out.
Thanks.
Kevin
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[Oliver Peters] “It’s mainly a nuisance when I bounce the footage out to SD and then ingest it back in as SD.”
I’ll be interested to hear what you find out also. I ran into this myself about a year ago, and when I contacted AJA about, they didn’t really have an answer for me. Maybe you will have better luck explaining the situation. I saw it on a Kona 2 and 3 on separate machines, so I don’t think it’s a driver issue.
(In all other cases though, AJA support has been great)
2 x3Ghz Quad MacPro
9 GB RAM
Mac OS X 10.5.5
QT 7.5.5
FCP 6.0.5
AJA Kona 3 (6.0.1 drivers)
G-Speed XL 12 RAID -
[Kevin Wild] “What is the difference between field order vs field dominance?”
Kevin,
Field order and field dominance relate to interlaced frames. Field order is whether the scan lines of a complete frame start on the odd (Upper) numbered or even (Lower) numbered lines when displaying an interlaced frame. Or from Adobe:
“The field order for an interlaced video footage item determines the order in which the two video fields (upper and lower) are displayed. A system that draws the upper lines before the lower lines is called upper-field first; one that draws the lower lines before the upper lines is called lower-field first. Many standard-definition formats (such as DV NTSC) are lower-field first, whereas many high-definition formats (such as 1080i DVCPRO HD) are upper-field first.”
Field dominance is whether an edit point or a cut occurs on Field 2 or Field 1 of a frame. From Wikipedia:
https://en.wikipedia.org/wiki/Field_dominance
Basically Field Order is a dislay issue whereas Field Dominance is an edit issue.
Although I point out the FCP discrepancy, I should add that many manufacturers use these two terms interchangeably. That’s wrong, but they all do it – hence, all the confusion. In the case of all NLEs that I know of, the edits are all Field 1 dominant, regardless of whether the Field Order is upper, lower or none (progressive). This means when you park on an edit point, you are on the complete frame of that timecode value. If you re-edit material that was already edited and is Field 2 dominant, any given cut with be a split-field frame showing one field of the outgoing frame mixed with a field on the incoming frame.
Sorry for the lengthy explanation. Hope that helps.
– Oliver
Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com -
[Matt Larson] “I’ll be interested to hear what you find out also. I ran into this myself about a year ago, and when I contacted AJA about, they didn’t really have an answer for me. “
Matt,
I have been in contact with AJA and have a few things to test. So it will probably be a few days. The preliminary info I’m getting from AJA is that the frame-doubling occurs in FCP. FCP takes the 29.97p timeline, adds the 2:2 cadence and “presents” it to the Kona card as “standard” 720p/59.94 video. BTW – this is apparently also what Avid does in their hardware. So in each case, the NLE software is doing the work. More to come.
– Oliver
Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com -
How is field dominance marked or flagged in a digital video signal? And obviously it has no meaning in progressive formats, so in that case, is there a marker that identifies a frame as the first frame in a pair when you are in 720p29.97? In other words, what keeps 720p29.97 from being plain old 720p59.94? If there is such a marker, wouldn’t it be in a sort of conflict with the 720p59.94 time code, which would also define the start and end of each frame?
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[Tom Brooks] “How is field dominance marked or flagged in a digital video signal?”
Through TC and the inherent nature of the device itself. Jog through a VTR and you can see where the cuts occur as compared to when TC changes. All devices have a field dominance setting. VTRs and switchers have actual menu settings to set them to be F1, F2 or F1/F2 (driven by external commands). I don’t know on NLEs, because AFAIK, you cannot change it on them. In a VTR, if the switch is set to F1 Dom, then an insert/assemble edit made on the VTR itself cannot occur on F2.
[Tom Brooks] “In other words, what keeps 720p29.97 from being plain old 720p59.94?”
720p/29.97 as a format technically doesn’t exist, as Walter has pointed out. It DOES exist, however, in P2 media (and JVC’s HDV) and various software apps, including FCP. When you drop a 29.97PN (native) clip on a blank FCP timeline, the settings are changed to a 29.97 – NOT 59.94 – timebase. All edits and TC are based only on 30 intervals/sec. When you play that through hardware – like the Kona card – that expects to get 720p/59.94, the software doubles the frames in the stream. An exported QT would only be 29.97.
This issue I’m hitting is that in order to turn 30 frames into 60 frames or 60 fields, something has to determine whether the first frame starts on timecode Frame 1 at Field 1 or 2 (interlaced). Since frames are doubled in progressive, the 30 frames of a 29.97 timeline become 60 frames of a 59.94p timeline. In effect, each timecode value in the 29.97 timeline corresponds to every-other timecode value in the resulting 59.94p video stream. As with interlaced, the software must determine whether this starts on even or odd frames. In other words, does Frame 1, 2, 3, etc. (29.97) = Frame 1, 3, 5, etc. – OR – Frame 0, 2, 4, etc. (59.94)? And can this be changed or adjusted?
Does you head hurt yet? 😉
– Oliver
Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com -
[Oliver Peters] “Does you head hurt yet? 😉 “
Yes it does, but I look for things like this. Thx.
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