24P SP Mode Recording

Keith Moreau · September 2nd, 2008, 02:18 PM

Hi

I was shooting a long event the other day where the resolution wasn't critical but I knew I wanted a progressive format and the longest time per card available, so I chose the 1080 24P SP mode on the EX1. I chose 1/48 as the shutter speed (which I thought was correct for 24P footage). I had previous done a similar thing but had chosen 60i, and spent some time deinterlacing it to 30P, which looked ok but I wanted to avoid that problem this time.

I transferred using XDCAM Transfer tool to Quicktime wrapped files and realized that the files were basically 60i with pulldown added, which added horizontal interlacing lines to any moving edges (while viewing on a progressive monitor).

In Final Cut Pro I created a 24P (23.98) sequence to remove the pulldown (there wasn't another way in my research to do it effectively). I used the HDV 24P easy set up for the basic parameters, and dragged the 60i files will pulldown into it.

The resultant footage looks really jerky and juddery. It also appears the jerkiness isn't even, it appears to jerk in a cadence. Much worse than I think 24P should, much worse than the HQ 24P on the EX1.

Any hints to salvage this or make it better before I try this in the future? At this level of trouble I would be better off shooting in the 60i mode and just deinterlacing in post, which is what I did last time.

Here is a short sample of what I'm talking about:

http://kmpublishing.com/dvinfo/24p_T...uence-480p.mov

-Keith

Does anybody have a

Christopher Witz · September 2nd, 2008, 03:03 PM

oops... sorry wrong thread....

Eric Pascarelli · September 2nd, 2008, 04:17 PM

In the future use HQ!

You'll get true 24p footage with no interlace. With FCP it's a pretty flawless workflow.

Regarding deinterlacing your current footage, I'll defer to someone who has done it before - there may well be a way to do it on the fly in FCP or using Cinema Tools.

Keith Moreau · September 2nd, 2008, 04:40 PM

Yeah, HQ in the future is the way to go, not worth it to add 8 more minutes of time to each 8GB card, especially since I have to dump them realtime to my Macbook pro on longer than 1 hour events anyway. But still I'd like to know if I can make the 2.5 hours or so of 24P pulldown stuff work.

Brian Rhodes · September 2nd, 2008, 05:54 PM

Quote:

Originally Posted by Keith Moreau

Yeah, HQ in the future is the way to go, not worth it to add 8 more minutes of time to each 8GB card, especially since I have to dump them realtime to my Macbook pro on longer than 1 hour events anyway. But still I'd like to know if I can make the 2.5 hours or so of 24P pulldown stuff work.

Keith try using Cineform I think there is a ten day trial.

CineForm Home Page

David C. Williams · September 2nd, 2008, 06:22 PM

As mentioned, use HQ. I understand SP to be HDV emulation, so there is no true 24P, and it's always interlaced with pulldown. HQ does true 24P, or 23.98 really, no interlace.

Serena Steuart · September 2nd, 2008, 06:32 PM

Shooting at 24 fps requires discipline in camera movement, as learned by all who shoot film. If you want to do fast pans and zooms, stay with 60i.

Eric Pascarelli · September 2nd, 2008, 08:54 PM

Serena, that's true (though I think that point is perhaps overdone on this site - there are plenty of fast action scenes and whip pans shot at 24fps - the entire history of action cinema).

But in this case it's a workflow problem - if you look at the footage there's an out of phase 3-2 pulldown (or reverse pulldown) being "baked" into the footage.

HQ and true 24p will solve it for the future. Removing the 3-2 pulldown with the correct phase will fix the existing footage.

Serena Steuart · September 3rd, 2008, 01:57 AM

OK, I had only time for a very quick look and it appears that you're correct. Frame blurring is what makes 24 fps on film look fine (whip pans etc), and this is largely absent in the example discussed.

Keith Moreau · September 3rd, 2008, 11:54 AM

Hi Serena, thanks for the hints about 24P shooting, actually I'm pretty aware of the panning and zooming limits to avoid judder. I specifically chose a shot where there was a lot of movement to emphasize the unnatural judder present. I used a 1/48th shutter, or 180 degrees, which is standard in film for an appropriate amount of blur to minimize judder. I think a similar amount of movement in a true 24P recording would look a bit more natural than my clip.

One thing that we see a lot of nowadays is the 'docudrama' effect on all kinds of TV and movies, especially in action sequences to heighten a sense of reality. You'll see overly shaky handheld shots, a lot of quick and impromptu looking zooming ala news gathering. A lot of those are shot on 24P video or film, and they don't show the level of judder that's in my clips, so it is possible to get this effect in 24p.

Anyway, with some research I did find a way theoretically, with some work, to remove the pulldown frames. It involves Cinematools and knowing where the 'A' frames are in the sequence of frames. Seems to be a pretty crude way to accomplish this and quite time-consuming to process, and I have one of the fastest Mac Pro 8 core systems available. It just turned out to be way too much trouble to do it for 2.5 hours of video for a non-critical project.

I wound up just using Compressor, while creating the DVD files, to de-interlace all the footage to a 30p framerate, which smoothes out the interlacing comb artifacts. It doesn't totally eliminate the judder but at least is better than putting the 60i-24P video into a 24P timeline.

I'm not going to use the 24P SP mode on the EX1 again, way too much trouble. If II want to use the SP mode, shooting 60i and deinterlacing to 30P (which is what's I've done in the past) is much easier and looks fine.

Thanks everybody for your advice, if anybody has an easier workflow please feel free to contribute, I imaging others have run into this before, maybe there is a better solution.

-Keith

Serena Steuart · September 4th, 2008, 08:25 PM

A lesson to me to not hurry into a post when I haven't time to think adequately about the question. Being in 50Hz country I've been using only 25P (HQ) and 50i (SP) and didn't stop to think about SP mode 24 being transmogrified into 59.94i, even though the menu says 1080/24P. Mind you, you did say that in your post!

September 2nd, 2008, 02:18 PM	#1
Keith Moreau Major Player Join Date: Nov 2006 Location: Brisbane, California Posts: 530	24P SP Mode Recording - Excessive Judder Hi I was shooting a long event the other day where the resolution wasn't critical but I knew I wanted a progressive format and the longest time per card available, so I chose the 1080 24P SP mode on the EX1. I chose 1/48 as the shutter speed (which I thought was correct for 24P footage). I had previous done a similar thing but had chosen 60i, and spent some time deinterlacing it to 30P, which looked ok but I wanted to avoid that problem this time. I transferred using XDCAM Transfer tool to Quicktime wrapped files and realized that the files were basically 60i with pulldown added, which added horizontal interlacing lines to any moving edges (while viewing on a progressive monitor). In Final Cut Pro I created a 24P (23.98) sequence to remove the pulldown (there wasn't another way in my research to do it effectively). I used the HDV 24P easy set up for the basic parameters, and dragged the 60i files will pulldown into it. The resultant footage looks really jerky and juddery. It also appears the jerkiness isn't even, it appears to jerk in a cadence. Much worse than I think 24P should, much worse than the HQ 24P on the EX1. Any hints to salvage this or make it better before I try this in the future? At this level of trouble I would be better off shooting in the 60i mode and just deinterlacing in post, which is what I did last time. Here is a short sample of what I'm talking about: http://kmpublishing.com/dvinfo/24p_T...uence-480p.mov -Keith Does anybody have a Last edited by Keith Moreau; September 2nd, 2008 at 03:30 PM.

September 2nd, 2008, 03:03 PM	#2
Christopher Witz Major Player Join Date: Feb 2006 Location: Louisville, KY Posts: 591	oops... sorry wrong thread.... Last edited by Christopher Witz; September 2nd, 2008 at 03:04 PM. Reason: oops

September 2nd, 2008, 04:17 PM	#3
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	In the future use HQ! You'll get true 24p footage with no interlace. With FCP it's a pretty flawless workflow. Regarding deinterlacing your current footage, I'll defer to someone who has done it before - there may well be a way to do it on the fly in FCP or using Cinema Tools.

September 2nd, 2008, 04:40 PM	#4
Keith Moreau Major Player Join Date: Nov 2006 Location: Brisbane, California Posts: 530	Yeah, HQ in the future is the way to go, not worth it to add 8 more minutes of time to each 8GB card, especially since I have to dump them realtime to my Macbook pro on longer than 1 hour events anyway. But still I'd like to know if I can make the 2.5 hours or so of 24P pulldown stuff work.

September 2nd, 2008, 06:22 PM	#6
David C. Williams Major Player Join Date: Jun 2008 Location: melb.vic.au Posts: 447	As mentioned, use HQ. I understand SP to be HDV emulation, so there is no true 24P, and it's always interlaced with pulldown. HQ does true 24P, or 23.98 really, no interlace.

September 2nd, 2008, 06:32 PM	#7
Serena Steuart Major Player Join Date: Jun 2006 Location: Studio Alnitak, Melbourne, Victoria, Australia Posts: 640 Images: 3	Shooting at 24 fps requires discipline in camera movement, as learned by all who shoot film. If you want to do fast pans and zooms, stay with 60i.

September 2nd, 2008, 08:54 PM	#8
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	Serena, that's true (though I think that point is perhaps overdone on this site - there are plenty of fast action scenes and whip pans shot at 24fps - the entire history of action cinema). But in this case it's a workflow problem - if you look at the footage there's an out of phase 3-2 pulldown (or reverse pulldown) being "baked" into the footage. HQ and true 24p will solve it for the future. Removing the 3-2 pulldown with the correct phase will fix the existing footage.

September 3rd, 2008, 01:57 AM	#9
Serena Steuart Major Player Join Date: Jun 2006 Location: Studio Alnitak, Melbourne, Victoria, Australia Posts: 640 Images: 3	OK, I had only time for a very quick look and it appears that you're correct. Frame blurring is what makes 24 fps on film look fine (whip pans etc), and this is largely absent in the example discussed.

September 3rd, 2008, 11:54 AM	#10
Keith Moreau Major Player Join Date: Nov 2006 Location: Brisbane, California Posts: 530	Hi Serena, thanks for the hints about 24P shooting, actually I'm pretty aware of the panning and zooming limits to avoid judder. I specifically chose a shot where there was a lot of movement to emphasize the unnatural judder present. I used a 1/48th shutter, or 180 degrees, which is standard in film for an appropriate amount of blur to minimize judder. I think a similar amount of movement in a true 24P recording would look a bit more natural than my clip. One thing that we see a lot of nowadays is the 'docudrama' effect on all kinds of TV and movies, especially in action sequences to heighten a sense of reality. You'll see overly shaky handheld shots, a lot of quick and impromptu looking zooming ala news gathering. A lot of those are shot on 24P video or film, and they don't show the level of judder that's in my clips, so it is possible to get this effect in 24p. Anyway, with some research I did find a way theoretically, with some work, to remove the pulldown frames. It involves Cinematools and knowing where the 'A' frames are in the sequence of frames. Seems to be a pretty crude way to accomplish this and quite time-consuming to process, and I have one of the fastest Mac Pro 8 core systems available. It just turned out to be way too much trouble to do it for 2.5 hours of video for a non-critical project. I wound up just using Compressor, while creating the DVD files, to de-interlace all the footage to a 30p framerate, which smoothes out the interlacing comb artifacts. It doesn't totally eliminate the judder but at least is better than putting the 60i-24P video into a 24P timeline. I'm not going to use the 24P SP mode on the EX1 again, way too much trouble. If II want to use the SP mode, shooting 60i and deinterlacing to 30P (which is what's I've done in the past) is much easier and looks fine. Thanks everybody for your advice, if anybody has an easier workflow please feel free to contribute, I imaging others have run into this before, maybe there is a better solution. -Keith

September 4th, 2008, 08:25 PM	#11
Serena Steuart Major Player Join Date: Jun 2006 Location: Studio Alnitak, Melbourne, Victoria, Australia Posts: 640 Images: 3	A lesson to me to not hurry into a post when I haven't time to think adequately about the question. Being in 50Hz country I've been using only 25P (HQ) and 50i (SP) and didn't stop to think about SP mode 24 being transmogrified into 59.94i, even though the menu says 1080/24P. Mind you, you did say that in your post!