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23.98 pulldown removal makes strange timecode
The new IO driver, and the ability to remove ‘Pulldown’ in capture is great, however, the timecode for the resulting clip is still 29.97 with missing frame numbers. For example, when I advance the clip frame by frame, the timecode doesn’t go from 0-23 as expected, it goes from 0-29 with frames 3,8,13,18,23,28 missing. This seems to be creating problems with my EDL’s. The generated EDL from using these clips on my timeline create erroneous timecode numbers. As an example, the source timecode for one of my clips was 01:22:08:00, but the edl pointed to 01:42:40:00.
Not sure if one is causing the other, but certainly there is something not right about the timecode on the clips with pulldown removed.
AJA Tech, any ideas?
G5 dual 2.7, 4gb ram, Nvideo 6800
OS X 10.4.1
Final Cut Studio 5 -
11 Replies
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Removing pulldown is doing just that, removing (or more accurately skipping) frames. If you are removing advanced pulldown, FCP is skipping (i.e. not capturing) the frame with pulldown leaving you to edit with 24 progressive frames. Adding pulldown allows 24p to be recorded on to NTSC 60i tape, hence the 29.97 timecode. That’s why your timecode is the way it is. You aren’t recording 24 fps timecode, you are recording 29.97 frames a second with 29.97 fps timecode, and removing the ‘offending’ interlaced frame. Is the footage shot with advanced or normal pulldown?
See here:
https://www.adamwilt.com/24p/index.html#24pRecording
Jeremy
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G5 Dual 2Ghz <> 4GB RAM <> FCP 4.5 <> Kona 2ATTO 42XS <> Huge Systems 1.25 TB 4105 Fibre
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That is bad advice. If you are capturing 24p via 29.97 pulldown removal FCP SHOULD generate a new TC. Anyways, if I remember correctly FCP does not actually capture TC, it just conforms the first first frame to the first TC value and calculates the rest. So in theory it should be easy to implement for capture. But for sequence and other metadata? Who knows.
I will check later with the Io system. Maybe it is just a settings thing.
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MPE, no offense, but have you worked with 24p material w/ advanced pulldown? If FCP generated new timecode for captured clips, there would be no way to recapture offline clips.
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G5 Dual 2Ghz <> 4GB RAM <> FCP 4.5 <> Kona 2ATTO 42XS <> Huge Systems 1.25 TB 4105 Fibre
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Jeremy,
If what you say is correct, the how do you account for the fact that CINEMA TOOLS removes pulldown and generates a new TC that goes from 0-23, not 0-29 with missing frame numbers? If you have a clip with pulldown removed, in my book the TC should match the actual frame rate, anything else will just cause problems. What workflow do you use? -
Well, cinema tools is a different story. You are essentially creating new media with cinema tools, with new timecode (transcoding). FCP can remove advanced pulldown on the fly (through firewire sources such as dv or dv50) and pick off those frames with pulldown, but leaving the original timecode in tact for later recapturing. If the footage is shot 24p with normal pulldown (3:2) you have to use cinema tools for the processing to remove the pulldown. Does this make sense?
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G5 Dual 2Ghz <> 4GB RAM <> FCP 4.5 <> Kona 2ATTO 42XS <> Huge Systems 1.25 TB 4105 Fibre
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Jeremy,
I do see your point, especially when it comes to re-capturing. So why then does my EDL seem screwed up. Refering to my earlier post, I have footage on tape with standard pulldown (3:2) that I have captured and removed using AJA’s new IO driver. Once I have placed the resulting clips into my timeline and generate an EDL for another post house, my TC seems WAY WAY off. I will do another test, but there just seems to be something screwy going on and I don’t know if it a function of the new driver or what. -
[JeremyG] “If FCP generated new timecode for captured clips, there would be no way to recapture offline clips.”
You are incorrect because there is a direct relationship with 30i TC and 24p TC with pulldown. If there was not – how you think Avid, Quantel, Discreet can take a 30i EDL and recapture in a 24p project? Basically TC ending in 0s and 5s are pulldown frames. It is up to FCP to calculate the proper TC.
And yes I have worked on 24p Advance and normal pulldown – DV25/DV50, HDCAM and film.
HTH
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So my original question still stands. Is there a problem in the way the new IO driver assigns timecode after removing pulldown from capture?
It would be nice too if someone from AJA would chime in.
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In FCP there are 2 ways to view TC. Source and clip time. Source time will show the original TC of the tape which was at 29.97 minus the pulldown frames. If you want to view a 24fps frame rate, use Clip time and that will give you what you need. This is a workflow I use for 24@25 cutting. If you cntrl click on any of the TC fields in the viewer or canvas you can change it to source or clip time. You can also change your project properties (in the Edit menu) to globally change all the windows to view clip/source time.
As for the EDLs I think it is expected to have the Source time reflected there because you are going back to the original tape. Out of curiosity, why are you onlining in 24fps in standard definition? Or are you using HD? I am still trying to understand this workflow and am wondering how people find it useful. If your final output is tape, why not stay in 29.97?
gir
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[gir] “Source time will show the original TC of the tape which was at 29.97 minus the pulldown frames. If you want to view a 24fps frame rate, use Clip time and that will give you what you need.”
Genius, pure genius. Thank you my friend for pointing that out to me. I hadn’t realized that difference, so now it all makes sense. Still though, my EDL’s are generating bogus TC, that are WAY WAY off. This, I think, is still a bug. AJA?
In answer to your question about editing 23.98 vs 29.97 in SD. There are several benefits, one is a 20% savings in Harddrive storage for the same media, a 20% frame rate savings for CPU intentive renders, also a 20% savings in storage bandwidth for multiple realtime layers. Creatively, and workflow wise, there are benefits as well, for instance, never accidentily cutting on an Interlaced frame as I would with Telecined footage. Also, when adding graphics in AE, I don’t need to remove my pulldown for each clip becuase that’s already been taken care of during capture. There are also benefits when you are ready to create a DVD of your project. Creating a true 24p DVD (like Hollywood movies) has the same 20% savings in storage requirements and bit rates savings. So you can maximise the quality or increase the length of your show on your DVD. Making clips for the web can also be at 24p and have the same bandwidth savings.
Hope that answers your question.
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