Progressive confusion at DVinfo.net

Dushan Horvat · February 17th, 2004, 06:13 AM

Hi all,

I have just shot a few sequences with my DVX100 and I am experiencing alot of interlace problems with my 24p and 24a footage. When I shoot in 30p, I see no interlace lines.
How can I be having interlacing occur if I am shooting in 24p? I thought 24p was progressive frames?
And why do I not have interlace problem with 30p then?

If anyone has any thoughts, I would welcome it!

Zac Stein · February 17th, 2004, 06:35 AM

Could you please elaborate, are you seeing these problems on a tv or on your computer monitor?

24p is/are progressive frames, but are still recorded to the tape in an interlaced fashion, since that is all the standard will allow.

BUT rather than take 60 unique fields to tape, it takes 24 unique frames, which are then split up into a pull down and recorded to tape as 60 fields.

Essentially you are getting 24fps split and math crunched into 60 fields... but to answer your question you should not be seeing any interlacing artifacts.

Could you describe them further as well.

Zac

Dushan Horvat · February 17th, 2004, 01:17 PM

Well, this is what occurs:

If I film at 24p and then view it on a computer monitor, I will see the typical combing horizontal lines associated with interlacing.
The same goes when I film at 24a.
On a tv monitor, or even ati software ect that will play back video like a tv would, it does not show the horizontal combing effect. This shows the 24fps rates to be interlacing, which completely confuses me because I thought it was a progressive mode.

However, when I film at 30p, which is supposedly progressive as well, it does not have any interlacing lines when I view it on my computer monitor.

I typically capture my footage in Premiere 6.5.

So, that is what's happening, and I simply don't understand.. if you film at 30p, 24p or 24a, you shouldn't get any interlacing, correct? That doesn't seem to be the case for me... 30p has no interlace lines when I capture on premiere, but 24p and 24a does.

To add to the mystery, when I capture the 24p footage and render it out of premiere, I usually make the clips field options to "de-interlace". But when premiere renders it out and I look at it again on my computer, it didn't deinterlace at all. You still see the exact same horizontal lines.

Is there a way to post stills on here to show what I mean?

I really need help on this...

Barry Green · February 17th, 2004, 01:20 PM

Read the whitepaper at the top of this forum.

What you're seeing is the "pulldown" that happens to convert 24P into the format that gets written to tape: 60i.

The camera records regular interlaced 60i video, and converts the 24P frames to fit into those 60 fields. In editing you can reconstruct the original 24P frames losslessly, if you recorded in 24PA. 24PA records four pure 24P frames, and then one blended "fill-in-the-gap" frame, onto 5 video frames, to round up the 24 frame to fit onto 30 video frames per second.

Dushan Horvat · February 17th, 2004, 01:36 PM

Quote "Read the whitepaper at the top of this forum.

What you're seeing is the "pulldown" that happens to convert 24P into the format that gets written to tape: 60i.

The camera records regular interlaced 60i video, and converts the 24P frames to fit into those 60 fields. In editing you can reconstruct the original 24P frames losslessly, if you recorded in 24PA. 24PA records four pure 24P frames, and then one blended "fill-in-the-gap" frame, onto 5 video frames, to round up the 24 frame to fit onto 30 video frames per second."

Hmm..that may very well be it! I looked up at the top of the forum and I really have no clue where to find the "white paper" on this..if you could please point out the link, that would be wonderful.
Does the white paper explain how to reconstruct the frames properly in Premiere and after effects?
And can you reconstruct properly from 24p in Premiere, or does it have to be 24pa?
Thank you!

Stefan Scherperel · February 17th, 2004, 01:49 PM

Your problem is not the camera, it is premiere. I have been using premiere since 6.0 but have now switched to a premiere pro/vegas editing environment. Why vegas? because premiere does not support the pulldown associated with 24p or 24pa. When you convert footage that is 24p or 24pa to 24fps in premiere, it makes up it's own way of converting it. Granted, you should be able to edit 24p (f5) with premiere without problems, however I find vegas to be a much more suitable environment for 24fps editing (24p or 24pa). You could use a program called dv filmaker ($99) which will convert your footage to true 24fps quicktime for editing in premiere, but that's just one more step you have to go through. Save yourself some time and compression cycles and get vegas for all your 24p needs. (No I don't work for sony :).

Dushan Horvat · February 17th, 2004, 02:03 PM

Sigh...Adobe needs a head shake I think..
I have 6.5 AND Pro..but I use 6.5 more because it is less slugish. Are you guys saying that I am completely out of luck with even Premiere Pro? There is no way to make the 24p pull-down properly just in Premiere Pro?
Does After Effects 5 recognize 24p? What if I brought the raw DV into after effects, rendered it out as 24p targas and brought that into premiere. Would that eliminate the pull-down problem?
And I'm still curious where that white paper is.. :)

Rodger Marjama · February 17th, 2004, 02:42 PM

Sonic Foundry Vegas 4 + DVD Architect 24p Whitepaper is
http://mediasoftware.sonypictures.c...uctinfo/24p.pdf

You can edit 24PA material in premiere, you just need to use extra software to convert the 2:3:3:2 pulldown to 24fps progressive footage. DV Film Maker will do this and more http://www.dvfilm.com/maker/index.htm

Vegas is quickly becoming the PC standard for the DVX100 however, so you might want to weight the $95 .vs the higher $$$ option in Vegas 4.0.

-Rodger

Bryan Roberts · February 17th, 2004, 04:25 PM

Dushan - I used to be a strict Advocate of Premiere 6.5 for all my editing needs. I had tried Vegas but thought it to be a little childish or something. Well after I got my dvx100a, I was forced to give Vegas 4 a chance due to the 24p and now I've been converted. In my honest opinion, it's a much better and more powerful program to maximize your computer's potential. Premiere Pro just was way too sluggish for me. I have a p4 2.4 gigahertz and a Gig of RDRAM (that's right, the kind before DDR became the norm with HT) and I was furstrated with the slow performance of Pro and 6.5 even felt like it bogged down my system at times. Vegas flies. You'll welcome the change when you aren't spending so much time rendering transitions and such just to test them out before setting levels. You won't regret the Vegas investment. And, they have a promotion now where if you trade in your copy of Premiere, you can get Vegas for $299! Check this link out for more details:

http://mediasoftware.sonypictures.co...id=10&PRCat=30

Download the Demo and give the program a week and I'd be willing to bet you'll be a convert as well.... Best of luck.

..... I should get kickbacks for plugs like this ;)

Dushan Horvat · February 17th, 2004, 08:28 PM

Yes, perhaps Vegas is worth looking into, especially since I always use the DVX100...
Any yes Bryan, you should get something from them :)

Thank you guys for the info!

February 17th, 2004, 06:13 AM	#1
Dushan Horvat New Boot Join Date: Aug 2003 Posts: 22	Progressive confusion Hi all, I have just shot a few sequences with my DVX100 and I am experiencing alot of interlace problems with my 24p and 24a footage. When I shoot in 30p, I see no interlace lines. How can I be having interlacing occur if I am shooting in 24p? I thought 24p was progressive frames? And why do I not have interlace problem with 30p then? If anyone has any thoughts, I would welcome it!

February 17th, 2004, 02:42 PM	#8
Rodger Marjama Regular Crew Join Date: Sep 2002 Location: Loveland, CO Posts: 101	Sonic Foundry Vegas 4 + DVD Architect 24p Whitepaper is http://mediasoftware.sonypictures.c...uctinfo/24p.pdf You can edit 24PA material in premiere, you just need to use extra software to convert the 2:3:3:2 pulldown to 24fps progressive footage. DV Film Maker will do this and more http://www.dvfilm.com/maker/index.htm Vegas is quickly becoming the PC standard for the DVX100 however, so you might want to weight the $95 .vs the higher $$$ option in Vegas 4.0. -Rodger __________________ Rodger Marjama www.speedwing.net

February 17th, 2004, 06:35 AM	#2
Zac Stein Major Player Join Date: Aug 2002 Location: Melbourne, Australia Posts: 730	Could you please elaborate, are you seeing these problems on a tv or on your computer monitor? 24p is/are progressive frames, but are still recorded to the tape in an interlaced fashion, since that is all the standard will allow. BUT rather than take 60 unique fields to tape, it takes 24 unique frames, which are then split up into a pull down and recorded to tape as 60 fields. Essentially you are getting 24fps split and math crunched into 60 fields... but to answer your question you should not be seeing any interlacing artifacts. Could you describe them further as well. Zac

February 17th, 2004, 01:17 PM	#3
Dushan Horvat New Boot Join Date: Aug 2003 Posts: 22	Well, this is what occurs: If I film at 24p and then view it on a computer monitor, I will see the typical combing horizontal lines associated with interlacing. The same goes when I film at 24a. On a tv monitor, or even ati software ect that will play back video like a tv would, it does not show the horizontal combing effect. This shows the 24fps rates to be interlacing, which completely confuses me because I thought it was a progressive mode. However, when I film at 30p, which is supposedly progressive as well, it does not have any interlacing lines when I view it on my computer monitor. I typically capture my footage in Premiere 6.5. So, that is what's happening, and I simply don't understand.. if you film at 30p, 24p or 24a, you shouldn't get any interlacing, correct? That doesn't seem to be the case for me... 30p has no interlace lines when I capture on premiere, but 24p and 24a does. To add to the mystery, when I capture the 24p footage and render it out of premiere, I usually make the clips field options to "de-interlace". But when premiere renders it out and I look at it again on my computer, it didn't deinterlace at all. You still see the exact same horizontal lines. Is there a way to post stills on here to show what I mean? I really need help on this...

February 17th, 2004, 01:20 PM	#4
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Read the whitepaper at the top of this forum. What you're seeing is the "pulldown" that happens to convert 24P into the format that gets written to tape: 60i. The camera records regular interlaced 60i video, and converts the 24P frames to fit into those 60 fields. In editing you can reconstruct the original 24P frames losslessly, if you recorded in 24PA. 24PA records four pure 24P frames, and then one blended "fill-in-the-gap" frame, onto 5 video frames, to round up the 24 frame to fit onto 30 video frames per second.

February 17th, 2004, 01:36 PM	#5
Dushan Horvat New Boot Join Date: Aug 2003 Posts: 22	Quote "Read the whitepaper at the top of this forum. What you're seeing is the "pulldown" that happens to convert 24P into the format that gets written to tape: 60i. The camera records regular interlaced 60i video, and converts the 24P frames to fit into those 60 fields. In editing you can reconstruct the original 24P frames losslessly, if you recorded in 24PA. 24PA records four pure 24P frames, and then one blended "fill-in-the-gap" frame, onto 5 video frames, to round up the 24 frame to fit onto 30 video frames per second." Hmm..that may very well be it! I looked up at the top of the forum and I really have no clue where to find the "white paper" on this..if you could please point out the link, that would be wonderful. Does the white paper explain how to reconstruct the frames properly in Premiere and after effects? And can you reconstruct properly from 24p in Premiere, or does it have to be 24pa? Thank you!

February 17th, 2004, 01:49 PM	#6
Stefan Scherperel Major Player Join Date: Dec 2003 Location: Seattle WA Posts: 209	Your problem is not the camera, it is premiere. I have been using premiere since 6.0 but have now switched to a premiere pro/vegas editing environment. Why vegas? because premiere does not support the pulldown associated with 24p or 24pa. When you convert footage that is 24p or 24pa to 24fps in premiere, it makes up it's own way of converting it. Granted, you should be able to edit 24p (f5) with premiere without problems, however I find vegas to be a much more suitable environment for 24fps editing (24p or 24pa). You could use a program called dv filmaker ($99) which will convert your footage to true 24fps quicktime for editing in premiere, but that's just one more step you have to go through. Save yourself some time and compression cycles and get vegas for all your 24p needs. (No I don't work for sony :).

February 17th, 2004, 02:03 PM	#7
Dushan Horvat New Boot Join Date: Aug 2003 Posts: 22	Sigh...Adobe needs a head shake I think.. I have 6.5 AND Pro..but I use 6.5 more because it is less slugish. Are you guys saying that I am completely out of luck with even Premiere Pro? There is no way to make the 24p pull-down properly just in Premiere Pro? Does After Effects 5 recognize 24p? What if I brought the raw DV into after effects, rendered it out as 24p targas and brought that into premiere. Would that eliminate the pull-down problem? And I'm still curious where that white paper is.. :)

February 17th, 2004, 04:25 PM	#9
Bryan Roberts Major Player Join Date: Dec 2002 Location: Los Angeles, CA Posts: 436	Dushan - I used to be a strict Advocate of Premiere 6.5 for all my editing needs. I had tried Vegas but thought it to be a little childish or something. Well after I got my dvx100a, I was forced to give Vegas 4 a chance due to the 24p and now I've been converted. In my honest opinion, it's a much better and more powerful program to maximize your computer's potential. Premiere Pro just was way too sluggish for me. I have a p4 2.4 gigahertz and a Gig of RDRAM (that's right, the kind before DDR became the norm with HT) and I was furstrated with the slow performance of Pro and 6.5 even felt like it bogged down my system at times. Vegas flies. You'll welcome the change when you aren't spending so much time rendering transitions and such just to test them out before setting levels. You won't regret the Vegas investment. And, they have a promotion now where if you trade in your copy of Premiere, you can get Vegas for $299! Check this link out for more details: http://mediasoftware.sonypictures.co...id=10&PRCat=30 Download the Demo and give the program a week and I'd be willing to bet you'll be a convert as well.... Best of luck. ..... I should get kickbacks for plugs like this ;)

February 17th, 2004, 08:28 PM	#10
Dushan Horvat New Boot Join Date: Aug 2003 Posts: 22	Yes, perhaps Vegas is worth looking into, especially since I always use the DVX100... Any yes Bryan, you should get something from them :) Thank you guys for the info!