XL2 Footage Interlaced?
 

I have recorded several little test clips with my XL2 scince I have purchased it. I did a small review of the camera on another message board with some pictures and video clips of the test shots.

When I posted the pictures a guy mentioned "When you shoot shoot in 24p that the picture should not be interlaced, it just doesn't happen in progressive mode." I myself am rather new to all of it, and figured that it would be interlaced anyway you shot it until you deinterlaced it on your computer.

Now, the question is, am I doing something wrong with the camera? Could I be capturing the video with the wrong settings? I would like you hear what you guys have to say. This is the most helpful and intelligent DV community I have been to.

Thanks!

Both 30p and 24p are true progressive in the XL2, but there is a caveat: the miniDV signal laid onto the tape is always 60i. SAY WHAT?

There are other threads here that describe this in much greater detail, but in a nutshell...in 30p, both fields of a given frame come off the same progressive scan image taken by the CCD block; they are two halves of the exact same image. So, no interlacing artifact occurs regardless of the playback device.

To get 24p-frames-per-second onto a 60i-fields-per-second signal, the camera uses one of two "pull down" patterns:
-- A 2:3 pattern of fields (2 identical fields are laid down on the tape for the first frame of 24p, then 3 fields for the next frame, then 2, etc.), or
-- A 2:3:3:2 pattern.

Then your editing software has to be able to recognize these pull-down patterns to either properly interpret them into a 60i timeline (in the case of 2:3), or extract repeat information so a 24p timeline has 24 frames per second, not 30. In the illustrations below that represent a one second clip, each letter represents a field. Each pair of letters represents a 2-field frame:

2:3 (on tape or a 60i timeline)
AA BB BC CD DD EE FF FG GH HH II JJ JK KL LL MM NN NO OP PP QQ RR RS ST TT UU VV VW WX XX

2:3:3:2 (on the tape)
AA BB BC CC DD EE FF FG GG HH II JJ JK KK LL MM NN NO OO PP QQ RR RS SS TT UU VV VW WW XX

2:3:3:2 (how the fields are combined on a 24p timeline)
AA BB CC DD EE FF GG HH II JJ KK LL MM NN OO PP QQ RR SS TT UU VV WW XX (notice the six frames underlined are extracted, reducing the frame count from 30 to the original 24p!

The consensus around here is to use 2:3:3:2 pull down. If you look closely at the 2:3 pattern, there's no way to cleanly get rid of extra frames and be left with the original progessive frames. Once you've shot 2:3, there's no going back -- you either have to export it to an interlaced final product, or, if it is even practical, do a lot of post-production work to minimize the interlacing artifact that'll be induced by rendering back to progressive footage, either 24p or 30p.

But from a 24p timeline that extracted the extra "mixed field frames" (that are underlined in the illustration) from a 2:3:3:2 tape, you can still use 2:3 to render to 60i, or simply export to your DVD in 24p and let the DVD player do the pullup.

Easy as A-B-C. NOT!!! Anyway, hope that gets you started on this confusing topic. There are a bunch more threads about it, so dig in. It definitely takes a while for it to sink in for most of us!

First off Thank you.

Very informative.

I didn't know too much about the whole pulldown options.

I saw some people explain it in other topics but I wasn't really able to comprehend it. Luckily with your post I believe I got it down.

Just one last question just to be sure, shoot it 2:3 or 2:3:3:2 pulldown? If I shoot in 2:3:3:2 pulldown I will still be able to edit it with me NLE and export to watch and post on the internet correct?

In it's description it acts as if it is ONLY for exporting to film, as if you were to take it straight to film. I was just wanting to make sure before I shot something important and then couldn't do anything with it.

Thanks again for your time.

The general advice is to set the XL2 on 2:3:3:2 and leave it there unless you have a specific reason you want to use 2:3. Since what you want to do is shoot 24p for the internet -- which means people will be viewing on a (progressive scan) computer monitor -- you definitely would want 2:3:3:2 on a 24p timeline and rendered to a 24p final file. The video will be free of interlace artifact and the file will be smaller since you're encoding only 24 frames each second instead of 30.

Only the newer versions of the mainstream consumer / prosumer editing software are sure to handle 24p footage. Low-end or older versions may not. Premiere Pro 1.5 does but Premiere 6, if I recall correctly, does not. I believe Vegas users have said Vegas 4 does 24p. Off the top of my skull, I don't know about others. What software and version are you using?

It occurs to me that I'm speaking about NTSC -- if you're in PAL-land, there would be different issues going for output to TV since PAL is 50i. I've lived in the UK and Germany in the past, but have never really dealt with PAL editing so if that's an issue, I'll have to leave it to others.

Definitely do a search within DVinfo.net if you haven't already, though. I think the pull-down issue has been sliced and diced just about every which way, not only on the XL2 forums, but the DVX and NLE areas.

Well, off to the airport to pick up my wife so no more posts tonight!

Ciao for now!

PS: Quick edit. If you are using an older version of Premiere, my 2 cents is DO upgrade to PPro 1.5 for the 24p and well as many other enhancements. Regardless of which software you use, though, you need the 24p-awareness.

I got Premiere 6 LE (Came with my comp and its a stripped down version), and Pinnacle Studio 9 (extremely buggy and I doubt it's compatible). I will have to try it. Premiere has a setting for 24fps when opening a new Composition, so it may or may not work. I will definitely give it a try. Thanks alot for you help. I will look up the other topics on the forum and hopefully I will be able to understand them better.

Thanks

Premiere 6 is incapable of removing the pulldown.

You have to either upgrade to a 24P-aware editor (such as Vegas 5) or, you can go to DVFILM.COM and buy their "Maker" software, which will convert a 2:3 or 2:3:3:2 file into a 24P quicktime file, which Premiere 6 would be able to edit.

Otherwise, if you want to use Premiere 6, you should use 2:3 pulldown and understand that there will always be interlace lines in your footage.

Let me just add one little bit of clarification to Pete's already very clear explanation. The group AA or BB does not represent two identical filelds taken from a single exposure but rather the odd and even fields from that exposure. AA' BB' BC' CC' DD' might be clearer with X representing the odd (or even) field and X' representing the other (which depending on the precedence). Note: I put BC' for the mixed field but I suppose it could equally well be CB' - the requirement being one odd and one even field. There is probably a standard which prescribes which way it is to be done.

As this keeps coming up I've put a short .dv file at http://homepage.mac.com/ajdel/FileSharing7.html
which contains 4 brief clips in, respectively, 60i, 30p, 24p (2:3:3:2) and 24p (2:3) modes from the XL2. The video is of a ceiling fan and I used a fast shutter so individual blade images are sharp. If you download this (45 Mb) and look at it in Quicktime (be sure to set High Quality otherwize Quicktime drops 1 field) or your NLE (29.97 timebase) one frame at a time it's easy to see what is going on in each of these modes. It is also very instructive to use an external monitor set to 60i simultaneosly.

60i: On your computer, which shows one frame at a time, you will see two displaced fields for every frame so that the image is blurry. On an external monitor you will see two fields in stop motion as the interface plays back both fields separated by 1/60th of a second and then repeats them. On the external monitor the motion is the smoothest in normal playback. On the computer the motion is smooth but the images are not sharp.

30p: On your computer you will see a clear, single image for each frame. The external monitor will show the same. Motion will be a little jerky relative to 60i on the external monitor. Motion on the computer display will be the same as on the external monitor.

24p (2:3:3:2): You will see 4 clear single field frames (YY', ZZ', AA', BB') followed by 1 double frame (BC') which will be blurred on the computer and shifting back and forth at a 60Hz rate on the monitor. This one has more of a strobed appearance on the monitor but looks better on the computer because 20% of the frames are double (interlaced).

24p (2:3): Similar except that there are 3 clear frames (ZZ', AA', BB') followed by 2 blurred frames (BC',CD'). This looks a little smoother on the monitor (40% of frames are interlaced) but blurrier on the computer.

Very nice!! Thanks a lot! This was a great help!

<<<-- Originally posted by A. J. deLange : As this keeps coming up I've put a short .dv file at http://homepage.mac.com/ajdel/FileSharing7.html-->>>

Hi AJ !

I tried out your footage in Vegas 5.0 . I cut the footage in 4 seperate clips.

When I start a DV 24p project in Vegas and import the 2:3 clip, I can get a clean 24p footage by using the remove 2:3 pulldown and selecting what framecount it starts in. But I can't do the same thing with the 2:3:3:2 because because there is no remove 2:3:3:2 option.

How can I correctly turn this clip in 24p ?

Do you know ?

Thanks !

Frank

Frank,

No, I'm afraid I know nothing about Vegas. Barry's post earlier indicates that it is 24p aware so you must be able to do it but I don't know how.

You have to be using a 24P project (start a new project and choose "DV 24P widescreen") and then you also have to go into the options and make sure that "allow pulldown removal from 24P footage" is checked.

After doing that, it should just work. When you import a clip, and check the properties, it'll say "DV - removing 2-3 pulldown" or "DV - removing 2:3:3:2 pulldown".

You don't have to manually remove pulldown from a clip, vegas will do that automatically if you have "Allow pulldown removal" selected.

I've done all the above but when I try to make a 24p dvd ( using dv film maker to remove the 2:3:3:2 and tmpgen 2.5 and ulead to burn) the dvd is sharp but camera movements are terrilbly jerky. What to do? ( this is on nonedited footage)

Go back to 60i! That's the mode that gives the appearance of smooth motion when viewed on an NTSC monitor. You use 24p because you WANT the jerky movements which are typical of film. 24p takes 40% of the number of pictures in a second that 60i does.

So, we can't expect good results on a DVD if we shoot in 24p 2:3:3:2 pull down? Or are you just saying to convert back to 60i (If that is possible)? I got a bit confused.