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-   -   24 fps editing? (https://www.dvinfo.net/forum/techniques-independent-production/2108-24-fps-editing.html)

Shawn McBee May 22nd, 2002 02:14 AM

24 fps editing?
 
With the new 24fps MiniDV cam coming out, I was wondering what editing system(s) will allow you to edit actual 24fps dv without converting to NTSC or PAL and then outputting back to 24fps. I know Avid Filmcomposer handles 24 fps (obviously) but I don't think it accepts the DV format.

Can anyone help me out?

-Shawn

Rob Lohman May 22nd, 2002 05:39 AM

I don't think DV (currently) supports 24 fps. So the DV editors
out there won't either. If I understood it correctly the camera
shoots 24 fps but converts it to PAL/NTSC to stay withing the
DV specs. You will need to do a 3:2 pulldown to get back to 24
fps.

Adrian Douglas May 22nd, 2002 06:13 AM

Apple has an FCP package called 'Cinema Tools' that allows 24fps editing but it aint cheap US$2000 including FCP3 or $1000 on it's own. Check it out at the Apple website.

http://www.apple.com/cinematools/

Shawn McBee May 22nd, 2002 06:56 AM

The cinematools is just like a feature on the Avid XPressDV Powerpack, but it's real function is to create an EDL for film editing rather than actually editing at native 24fps, which doesn't help. I'm looking for a native 24fps dv solution because I think I may have figured out how to film 24fps with my XL1 (I have yet to test it, which is a few thousand dollars away - but i may actually be able to make the XL1 a variable frame-rate camera). If I were to take 24fps DV and convert to NTSC (or PAL) for editing and then output the final product to 24fps in Avid, would there be any loss of quality or any weird motion resulting?

-Shawn

Don Donatello May 22nd, 2002 11:21 AM

the 24p dv panasonic does not record to tape at 24fps .. it adds the" 3:2 " so it lays to tape NTSC 60i ( just like they do when they transfer 24fps FILM to TAPE)... when you edit - you are editing interlace video ...

when you need to go to FILM than you would remove the 3:2 to end up with 24fps ... normal TV's , monitors canNOT play back 24fps they need 29.97 ( 30fps) ....

Joe Redifer May 22nd, 2002 02:49 PM

Yeah but all NLE's do dissolves, fades and other stuff (title scrolls, etc) at 60i, which looks HORRIBLY BAD when the original production was shot at 30fps or 24fps. The NLE's need to have a user option to select what frame rate the rendered stuff happens at.

Rob Lohman May 23rd, 2002 03:10 AM

Jedi.... this is a hard question to answer, because at this moment
there is no true 24 fps DV camera available to test this. You could
perhaps construct an artificial 24 fps DV AVI file... In fact, this
should be very possible. I will need to run some test of this
though. Then you can test whether any NLE can process the
file. Let me run some tests first at home.

Shawn McBee May 23rd, 2002 03:38 PM

That would be really cool, Rob. Thanks,

Shawn

Rob Lohman May 24th, 2002 01:03 AM

I was home from work last night at 10:00 PM (or 22:00 hours)
so I hadn't time to test. Will do so this weekend though. Hold
on a little bit longer.

Rob Lohman May 29th, 2002 02:47 AM

Shawn,

I did my tests and these are my conclusions:

- DV does not seem to store the actual FPS or at least
Adobe Premiere 6 doesn't care about it
- If you alter the framerate of the AVI file (without changing
anything else, see below) the files does play faster/slower
and Premiere has no problems whatsoever with it
- If you want to output at a different FPS we need to alter
premiere's templates. This is possible.

Good news all-in-all. I used a little program called avifrate
to change an AVI's FPS without re-rendering it to test all
of this. You can find the program here:
http://www.inmatrix.com/files/avifrate_download.shtml

So if you where able to really construct a variable rate camera
we'd probably need this little utility to change the AVI since
it will probably contain the wrong FPS otherwise. And we need
to change some templates.....

If you want/need to know more you know where to find me.
I'm very interested in what you've come up with on your side!

Cheers!

Shawn McBee May 29th, 2002 06:41 AM

Thanks so much for the info, Rob. I'll keep you updated as I do more research on this.

-Shawn

ErikFilmcrew May 29th, 2002 08:04 AM

Just me thinking loud....



If the camera records 24fps (progressive). Then if I was to edit it with a standard DV system, I would go with PAL 25fps progressive settings (because the close fps match). Imagine that the 24p camera puts ever first frame after 24 on a 25th (don't know if this is the case). Then we would slow down the movie 4%, and after that, if we were to blow it up to film the movie would be 4% faster -Back to real 24p again without any loss what so ever in frames or quality. 24p will still be 24p if edited in a 24p System, so in order to have it for anything else than 24p or cinema you would still do the speed change.

Isn't the speed change always there when real film is transfered to video?

I've heard about movies shot on 24p and then edited on standard DV-Systems -offline, in low resolution and then batch outputted to 24p. So it must work.

I don't think that this is much of a problem, really. Isn't it basicly the same problem as the "video to film" problem. Or rather method than problem.

But then again this is just me thinking loud.


Regards,

Erik T

Howard Phillips May 29th, 2002 10:47 AM

In v11 version of Avid editing systems, like FilmComposer Media Composers and Symphony, there's now a Firewire-In and Out via the BOB. Here's from their site:

"The new versions of Media Composer and Avid Xpress systems feature an option that enables native support of DV-format media, including input and output of DV25 media through a standard IEEE 1394 (FireWire) connection.."

Assuming the Panasonic 24p mini_DV generates a consistent 'pulldown' onto the tape, this should be a perfect match, with Avid 24p projects removing the extra fields the way it currently does for any other 24fps-NTSC project.
There's also a harware option with FCP, using a CinéWave board to remove the extra fields, to capture & edit at 24fps.

Rob Lohman May 30th, 2002 02:13 AM

Erik,

Editing a true 24 FPS DV source is not a problem, at least not
with Premiere. This is what my tests brought to light. It does
require the editing of a profile, but that is quite easy.

The problem is getting the camera to output anything else. Shawn
seems to have a lead on this and is working on it. I'm eager
to learn what he comes up with.

Cheers!

Martin Munthe June 1st, 2002 04:18 AM

Erik,

You and I are fortunate to be in a PAL 25fps world. NTSC 29.97fps offers a much bigger problem in a 24fps situation. You have to start thinking 2:3 pulldown for those guys across the Atlantic. Most Swedish HD films are actually shot in 25p (like Den Osynlige and Livvakterna). Most of the 16/35mm films are shot in 25fps with a 3.3333% tonal pitch for theatrical release (24fps projected).

Rob,

You can't output the 24fps to a monitor can you? It's all CPU, right?

Rumours say Apple will be releasing a 24p DV codec for FCP. This way you will capture 24, edit 24 and output 24 much like the Aurora Igniter Film option or the Avid Filmcomposer.

ErikFilmcrew June 1st, 2002 06:26 AM

Martin,

I did know of commercials shot on 25fps and screened 24fps. But never would I think that 16/35mm or HD 24p movies would be shot 25fps or "25p". One starts to think; what is this miniDV 24p camera worth. Really, the XL1 (PAL) can do the same thing in the end.

Thanks for the info Martin.

Also, excuse me for asking, but are you related to Bo F. Munthe in any way?



Regards / Med vänlig hälsning,



Erik

Rob Lohman June 1st, 2002 07:06 AM

The question about the monitor is a valid one, but the bigger
DV cards might be able to handle this problem (not sure though).

On my PC monitor I have no problem whatsoever ofcourse, and
if I want to test it I can make a progressive DVD file and play that
out through my hardware mpeg decoder in my PC to a TV.

Anything yet Shawn?

Martin Munthe June 1st, 2002 11:21 AM

Erik,

the benefit of a 24p DV camera would be true progressive in a prosumer camcorder. Something we have not seen so far...

And, yes, I am related to that perticular Ninja Master you mentioned :)

Rob,

on most smaller projects you are probably ok just using the CPU. On long form projects however there are great risks of sync drifts and drop frames if the CPU is the only thing working. The more referal files you have in a project the more demanding on the CPU it will be. I don't think there are any video cards for the pc that can do 24fps. As far as I know IgniterRT with Film Option is the only sub $20K card that can do it. Messing with the fps setting in Premiere could give you problems with the DV codec algorithms. Have not tried it though. It could be hazardous to the image quality output (probably producing an unsharp image). DV is sensitive to recompression as it is. I've posted some recompression examples between DV and Uncompressed D1. They are here:

http://www.operafilm.com/codecs.html

Hope it's of use to someone. Good luck with the tweaking!

Shawn McBee June 1st, 2002 11:54 AM

My Experiment
 
I'm quite a way off from knowing anything, as I have to purchase several things and only have about 1200.oo a month to spend on video equipment. But I figure I'll run my idea past you fine folks and see if any of you think it's even feasable...

The idea is to get a firestore direct-to-disc interface, have a custom electronics maker come up with a circuit board that would make a brief connection between two wires attached to the chipbase 24 times each second. These wires would then be plugged into the Firestore to act as a GPI trigger.

That idea led me to think: if a circuit could be made to do that, then why not program several different "frame rates" into it and have a switch or a knob to select them. Make a little casing for the circuit board, and you'd be ready to go.

It really seems like it'd work to me, for the most part. I can see some small issues that might arise, that would have work-arounds:

1) I'm not sure how the firestore works with it's GPI trigger, but it may only record Image when the GPI is triggered, so audio would have to be recorded seperately. Or it may sound stuttered if it records sound with each tiny trigger, but not a constant sound, which would have the same solution.

2) I'm also not sure if it would record properly to the DV tape, I think it would probably either record to tape at normal NTSC (or PAL, depending) and your selected Framerate on your drive or you'd just have to forego the tape altogether and take just straight hard dirve data with no backup.

other than that, I think it could work (and on any MiniDV cam!).

So, do any of you more experienced folks think it floats, or am I just grasping at straws?

-Shawn

Martin Munthe June 1st, 2002 02:47 PM

Nothing is impossible... I hope?

The thing that comes to mind with your invention is; how are you going to view this? When editing the material are you then going to send it out through the same circuitry to a broadcast monitor? Will the monitor be able to show the 24fps signal your circuit produces?

Shawn McBee June 1st, 2002 08:22 PM

I hadn't really considered the monitor issue. I was mainly focused on the editing issue, which is why I started this thread.

I imagine I'd be able to run RCA out of the camera and view what I'm filming at regular NTSC from the camera before it goes to the firestore (similar to a videotap on a film camera) and use a 2:3 pulldown for editing and any video/dvd dubs, but remove the 2:3 for the possibility of a film dub.

Now I just need to learn about 2:3 pulldown... time to use that nifty "search" option!

-Shawn

Martin Munthe June 2nd, 2002 04:06 AM

<<<-- I was mainly focused on the editing issue-->>>

I understand that and that's why I am asking. I guess you would like to color correct your material proper to broadcast standards and with a bit of artistic flare? Thats really impossible to do if you haven't got some form of reference monitor video output from your NLE. I've tried to calibrate CRT's to do broadcast colors but it is not possible. If you are producing films for the web this will be no problem since the web is viewed on CRT's and not TV sets.

Also, if your not doing any form of CC or image adjustments I guess it would work to just cut your video stream on a CRT and then take the project somewhere else for CC. I would definately CC before I print out to film. It will cost you a lot more to CC the film.

Perhaps there is some scan converter that could do the trick?

Shawn McBee June 2nd, 2002 04:24 AM

I will have an actual video monitor hooked into the NLE and from what I understand if, while I'm editing, I have the 2:3 pulldown, it should be totally viewable on the monitor, so I can do any color correction or whatever else I'd like.

-Shawn

ErikFilmcrew June 2nd, 2002 04:28 AM

Martin,


I've also heard that the XL1 doesn't produce a real progressive image. But what is the real difference? The XL1 records 2 fields at the same time. If you put these together on 35mm film, then there will be a sharp frame even at motion. Can't the XL1 in the end be regarded as a real progressive camera although it's really not?



I suspected that you were related to the Ninja master. Munthe isn't an ordinary name, and few of them work with film.



Regards,



Erik

Casey Visco June 2nd, 2002 09:44 AM

Erik, the XL1 does not record 2 distinct fields at the same time....it only records 1 field through the lens and interpolates the other. And even still, these are recorded to the tape in an interlaced form. It can therefore not be regarded as a progressive scan camera.

Rob Lohman June 3rd, 2002 02:59 AM

Martin,

Editing 24 fps DV is no problem, also not for the DV codec because
DV is like a JPEG compression, it is not like an MPEG compression
where frames interact with each-other. So this is totally safe.
As I said earlier, the monitor might be a problem. In regards to
your statement that it is a lot of work for the CPU to keep
video and audio in sync, I have to disagree. I, personally, have
never had a problem with audio sync. If you have a pretty
new CPU (at least 1 GHz) I doubt it will have much to do. These
CPU's are very fast!

Casey,

It is correct that the camera is interpolating more or less, but
it is not as simple as capturing one field and interpolating to
get the second field. There is done more. Also the material
on tape is not layed down as interlaced footage. It is recorded
as a single frame. An NLE does not know if the footage is
interlaced or not, you usually have to tell them or they guess
it on their own. For example, the Microsoft AVI standard does
not even have a way to indicate if the source if interlaced or
not! (weird enough, but actually true).

Shawn,

I don't think I'm understanding your solution 100%, but I got
a feeling this might not work. The camera outputs a 25 or
29.97 fps signal and the firestore just dumps this signal to a
harddisk (basically). The firestor doesn't do any "capture",
so will therefor not be able to capture in intervals (that is
basically what you are suggesting, right?). This would be
the same as to do drop some frames from the actual DV stream
once you have it in a PC (only less smooth, I agree). It probably
will be more interesting to use the analog outputs of the camera,
hook it up to a professional capture board at let that thing
capture at 24 fps.

Just some thoughts....

Shawn McBee June 3rd, 2002 05:30 AM

Rob,

The firestore has a "REC Still" button. This can be used in one of two ways: You can press the button, record one still frame as it's own file, press it again and record another still frame as another seperate file....etc. OR... you can press the button and each time you do so it will record another single frame onto the same file. (A neat trick if you want to do a DV stop-motion movie without killing your camera's heads). The GPI port affects this feature (I think they had time-lapse recording in mind) so, really, if my idea worked, you'd be recording 24 still images per second (just like film) as one file that, when put in an NLE and played at 24 fps would, hopefully, play back at a true 24 fps, with a more filmic look. (Of course bettered by good lighting, depth of field and all that other good stuff....Just a disclaimer to keep the different film-look schools from debating over this small issue here)

I hope that explains it a bit better. If anyone knows for a fact that it wouldn't work....let me know. It'll at least save me some money.

-Shawn

Rob Lohman June 3rd, 2002 06:01 AM

Ah... I didn't know that Shawn, my bad. This does sound
interesting indeed. I am wondering how they do this.


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