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Workflow w/ Teranex Question
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>>How is what I want to do any different? Isn’t it essentially the same exact concept?
No, it isn’t. What you described only works in 720p, because the source is “24 in 60,” that is, it isn’t a 24 frame video format. 720p/24 doesn’t exist as a video format, only 720p/60 does. So when you pull in from a 1200 deck, you can remove the pulldown on ingest, and create new time code that is a 23.98 base rate – but that doesn’t get you anywhere when the material doesn’t have 3:2 pulldown in the first place. Nor does you method exist when you play out 720 as 1080 using the 1200 with an HD-SDI board, because what you have to do in that case is feed the deck 23.98 trilevel sync – thus putting it into what essentially is a 24 frame mode. Your output in this mode is true 1080/24p, with the timecode also being converted to 23.98 time code.
The original question seems to me to be referring to material in two completely different origination formats – one being 24p, and the other being 60i. There is no way to masquerade 60i material as 24p if it didn’t originate that way, either by being 24 frame material padded with 3:2 pulldown to make 60, or by being 24 frame original (such as a film transfer). The simplest way to mix such formats is to make a 60 field based master, which accommodates both.
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[Sean ONeil] ” Video output is 23.98, but the offline clips are 29.97. Deck control and the TC from the deck is also 29.97.”
Have you ever studied the tc of a 23.98 captured varicam clip? It’s incongruous as well.
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[JeremyG] “The timecode is based on 29.97, not 23.98. When using the Bm or AJA cards to capture they simply skip frames in the 29.97 cadence.”
Yes I know, exactly! So why wouldn’t the same thing apply in this case? TC and deck control is 29.97, but the actual video being fed into the computer is 23.98. Again, as far as FCP is concerned, how is this any different?
[Mike Most] “There is no way to masquerade 60i material as 24p if it didn’t originate that way,”
It’s not masqerading. It’s actually being converted to 24p before it reaches the SDI capture card.[Mike Most] “No, it isn’t. What you described only works in 720p, because the source is “24 in 60,” that is, it isn’t a 24 frame video format. 720p/24 doesn’t exist as a video format, only 720p/60 does. So when you pull in from a 1200 deck, you can remove the pulldown on ingest, and create new time code that is a 23.98 base rate”
It doesn’t create new 24p timecode. It maintains the 29.97 timecode. Try it out. Jog through a clip and look at the source TC. It’s still 29.97. It just skips frame counts (as Jeremy stated). That’s why I feel there’s a remote possibility that what I wanted to do might work. And if it doesn’t, someone should come out with a little black box you plug the 9-pin into which could allow this to work.
But you are right. Mastering the project at 1080 60i would have made this a lot easier.
Sean
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[gary adcock] “I only got some of it wrong, I have a Mini unit from Terranex and it does not handle 1080 23.98 material- I have been told by them only the full size unit has the ability to handle 1080 23.98 content.
I agree with Mike Most’s comments- your stand a better chance for success following his guide line. FCP will not have an issue if the TC is identical but remember that you will have to convert your 29.97 edl to a 23.98 timeline ( in Cinema Tools)”
I see the confusion. So the Mini works differently. The place I went to has the full size Xantus which did it fine. But that’s good to know since I’ve been considering puchasing the Mini.
The job’s already over. I just made a clip reel which they converted and then I eye matched them back in. I’m just hoping to figure out a good solution for next time. FCP can put 29.97 TC onto 23.98 video, so I still think what I wanted to do could work.
Sean
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[Sean ONeil] “Yes I know, exactly! So why wouldn’t the same thing apply in this case? TC and deck control is 29.97, but the actual video being fed into the computer is 23.98. Again, as far as FCP is concerned, how is this any different?”
Does the digibeta have any sort of pulldown?
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In thinking about this some more, I believe what you’re really trying to do is convert 60i material, with its 60i time code, to 24 frame material, with 23.98 time code that “matches” the original 60i code (at least at even seconds, with the “0” and “5” conventions applied for 3:2 cadence) in one pass. This is not going to happen through a Teranex or any other converter because they don’t convert time code. The only way I can see to do what you’re talking about is to make a “pre-conversion” using an editing controller that can simultaneously sync up a 23.98 based HD VTR and a 60i based NTSC VTR. The only editing controller that I know of that can do this is the Time Logic Controller (TLC) that is built into most DaVinci installations. The TLC can control both machines and also account for the delay through a converter such as the Teranex. I was faced with having to develop a post path for a mixed format project just recently, and offered this as a possible solution to make a 24p master, but in the end, it was much more sensible to go 60i for the master for many of the same reasons I’ve mentioned here. Not only did it solve the workflow issues, it also allowed for the 60i material to be integrated without degredation – and no matter how you do it, there’s going to be degredation when you’re converting 60i material to 24p, simply because none of the resulting frames are directly photographed – they’re all interpolated. You get a softer image and unpredictable motion anomalies based on the material content. That’s one of the reasons they, and I, chose to go 60i.
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Mike, I totally agree that 60i would have been a better choice. However, the video-based footage that was converted to 23.98 really does look great. 90% of the footage was shot at 23.98, so I chose to make the master 23.98.
[Mike Most] “In thinking about this some more, I believe what you’re really trying to do is convert 60i material, with its 60i time code, to 24 frame material, with 23.98 time code… This is not going to happen through a Teranex or any other converter because they don’t convert time code. T”
I don’t beleive that needs to happen. You see, FCP does not need to convert the TC. It can handle having 60i TC tacked onto 24fps material. I don’t mean pulldown. I mean true 23.98 footage can have 60i TC. FCP does this by skipping frame numbers. So when you jog throuh it, the frame count will go 1, 2, 3, 5, 6, 8, 9, 10, 11, 13… 25, 26, 28, 29, 30. It skips a number every so often so that it ends up being 24 fps even though the TC format is that of SMPTE 29.97 TC.
So in other words, no TC conversion is actually needed, so a batch re-capture through a Teranex might work even if the framerate is being converted.
Sean
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Well, if you can actually get that to work, I’d like to know about it, because I think you’re still missing the point.
When you bring in 60i footage with 3:2 pulldown, Final Cut is still seeing 60 fields per second coming in, regardless of how you ingest it. It then drops some fields in terms of the Quicktime file it creates, but there is still a proper correlation between the controlling time code (at 29.97) and the number of video fields per second that it sees. When you try to bring in something that’s already 24 fps (23.98, in this case), there is no correlation between the controlling time code and the number of fields it’s now seeing – with in that case would be 48, if the material is coming in as 23.98 psF, as it likely would be. It won’t be able to figure out what fields to drop, and likely won’t be able to lock up the machine at all based on the fact that you’re giving it one time code standard, and a different video standard.
I’m perfectly willing to be proven wrong. But I don’t think I am.
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Mike, thanks for the clear explaination. Appreciate it. It makes perfect sense now, so now unfortunately I agree that it probably won’t work.
I understand now. With Varicam and pulldown removal capture, FCP is still being fed 60i/p in both scenarios. It’s not the same as being fed a true 24psf (48i) like it would be in my scenario. My misunderstanding led me to believe that FCP is able to ingest a video signal from one framerate whilst reading timecode of another framerate (like what the Davinci can do according to your earlier post). Thanks for clearing it up.
So if this is film-based material, the solution is to just have the Teranex output 60i and then have FCP remove the pulldown. Of course I had video-based footage being converted to 24p as well, and that of course wouldn’t work unless I had an additional device adding pulldown to it making it 60i.
Sean
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Yes, what you say would be a good solution. Bring in the film based SD footage as 1080i, and take out the pulldown in software. And for the 60i video originated footage, do the conversion and eye match the result.
Regarding the DaVinci: I was referring to the integrated editing system on the DaVinci, properly called the Time Logic Controller. This is a system that was specifically designed for the needs of telecine. What it does is control the telecine and the videtape machine(s), forcing the 3:2 pulldown to be on specific time code frames on SD transfers. Because of the unique need for simultaneous dual standard (HD and SD) transfers for dailies work, a special mode was created whereby the TLC can simultaneously sync videotape machines running in two different standards. It does this by using a special 6Hz pulse (supplied by a sync generator) to correlate the 24 frame material and the 30 frame material every 4 film frames, which is when “A” frames (the only film frame that exactly matches a video frame in the 5 field video sequence) are created. The spinoff of this ability is that you can use a TLC to sync HD and SD videotape machines, even when you’re not running film. It is the only device I know of that can do this, and for that reason, it is often used for audio laybacks from standard def to HD videotapes. Of course, because it lives as part of a $450,000 DaVinci system, it is often an expensive solution for facilities to provide, particularly because clients are reluctant to pay a full telecine room rate for a layback. But it’s sometimes the only one.
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