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Understanding 24p process
Let me see if I understand what the 24p process involves:
1) 24p mode = 2:3 pulldown: it means the camera (e.g. DVX100) will organize the 60i recording repeating and adding every second frame to get to 24p, which would be the 2:3 series.
2) 24p advanced mode = 2:3:3:2 pulldown: it means the camera (e.g. DVX100A) will organize the 60i recording alternating between 2:3 and 3:2 series.
3) 30p mode = the camera (e.g.: JVC HD100) will organize the 60i recording repeating every frame to get to 30p, in a 2:2 series.
Apparently this process is done using flags to organize all this. Is that right?
Do all cameras doing “real” 24p use this system: DV, HDV, HD?
What I wonder is what programs like DVFilm do to convert recorded video onto 24p, which aparently is what it does. Or am I wrong? Do they just add the flags or does it involve re-recording the original video (another generation, which would mean additional compressing/descompressing)?
Are there other programs that do that now?
When we deliver a 24p project to the lab for transfer to film, do we have to deliver it already processed? I mean if it was not shot in 24p, but processed through a program like DVFilm.
My lab requires me to deliver an HD with the whole editing, so as not to have additional compression from going to a tape, for instance.
Is there any other Creative Cow forum which discusses things like this?
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4 Replies
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Lots of questions here that depend on workflow, lab, abd other proceses.
Avid systems remove pulldown upon capture so you can edit native 23.976 or 24 in the timeline. It will do this for either NORMAL (2:3:2:3) or ADVANCED (2:3:3:2). It does not matter to the Avid once captured whether the material was NORNAL or ADVANCED, those are just means to store 23.976 originated material in a NTSC signal.
Delivery to the lab is a discussion between you and the lab. Some can just take your Avid project and MediaFiles, others will take a series of sequential graphic files such as TIFF, some will take a DV master output with NORMAL (2:3;2:3) pulldown which can easily be removed as part of the upconvert process, etc. Avid can output back to DV or digibeta or whatever NTSC master as NORNAL, ADVANCED or NONE. NONE is for picture only output that has no pulldown with a 2:2:2:2 pattern. This results in the program playing back 25% faster but removes the need for a downstream program to try and find the 2:3 cadence in the NTSC for removal. Especially useful for animation that animated on 2’s and 3’s and sometimes 4’s etc. Detecting a persistent cadence in that is very difficult if not impossible.
I am producing a feature now that was shot DV25. My process is edit at 14:1 (capture over FireWire) as an offline, racapture at 1:1 over FireWire so I don’t have to deal with a decompress/recompress whenever I render or send frames out for FX work. Once I have an uncompress master (no color correction yet), I will send out to After FX for an uprez process using Algolith and saving out to DNxHD 175 (or you can choose 115 with Xpress Pro). I reimport this back into my Media Composer (the new software only version will do all this). I check my uprez for frame accuracy against my offline. From there I send to my lab where they can take the DNxHD files in their Avid Symphony or or Avid DS for final correction and output to my HD master. From the Avid DS, I can export DPX files for an eventual film out if needed by distribution.
See my website at ww.24p.com for a variety of whitepapers on process and workflows for film and 24p material.
Michael
anything 24fps
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In fact, one thing I meant to know was if material that was not recorded as 24p can be converted to it, in a project intended for film transfer, before going to the lab.
If Avid removes the pulldown when capturing, then it seems as if you can output a “pulldowned” edit.
One thing I could at last find out is that my lab will charge me less if I deliver a 50i or 24p job than if I deliver 60i. In the first case as long as I transfer to 25fps.
So I am now wondering if there might be a way to convert my 60i original onto 24p. As far as I know, DVFilm program would do that, but I wonder how.
In any case I am not too sure it can be done, or Panasonic and others wouldn’t be making 24p cameras.
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Is your original material interlace? Is that the issue? And I now take it you are in a PAL country – so you should also be able to deliver them a 25p master for a film out as well. There are several programs that can convert 25i to 25p – DVFilmmaker, Magic Bullet, Boris, Algolith, or Avid’s own FluidFilm – there is an interlace to progressive preset.
Michael
anything 24fps
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Yes, original material is 60i. And not, I don’t live in a PAL country, though I would like to. Brazil’s system is an NTSC-modified country for color, but not for B&W.
In this case this material was shot in 60i because I was planning on an eventual video version, so an NTSC shoot would make things easier. Even if in this case I shot part of it in Argentina, which IS a PAL country. But as I had an NTSC DV camera and I had to shoot part of it in Brazil, I went ahead and shot that way in Argentina too.
Now I am facing more shooting, to convert this project in a eventual film feature, and I wonder how to best deal with the already shot material.
Any suggestions?
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