24P Advanced or 24P Standard?

I'm thinking 24P Standard would work just fine, and look just as good (and pose for less problems during editing, for hardware issues, and for synching issues, etc.).

 

Mhm.

...

I don't get it.

 

Advanced is known to cause trouble when capturing, from what I've heard. Always stuck with regular 24P myself.

 

No no no, for best quality, you must shoot 24p Advanced. If you shoot 24p Standard you will still have to de-interlace the footage, which will make you lose the nice progressive scan resolution. If you shoot in 24p Advanced, it saves 24p complete frames within the 30 frames laid to tape. That why you can drop the extra frames, and will have 24 distinct and whole frames to work with. Trust me on this one.

 

I'm pretty sure Advanced means real 24fps editing where standard
is 24fps with cadence added for 29.97fps editing.

To my knowledge only Sony Vegas and Final Cut Pro can
deal with the advanced version properly at this time,
without lockup issues during capture.


You really need not used Advanced unless your intend
to do a film-out.

 

Advanced, as I understand, can make for a smoother image with less juddering during quick camera motion. I haven't noticed any significant difference, though, and advanced just makes it harder to deal with. I'd agree with JBK, stick with standard.

M. Scott

 

PixelMagic posted on 9/8/05 11:11am

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No no no, for best quality, you must shoot 24p Advanced. If you shoot 24p Standard you will still have to de-interlace the footage, which will make you lose the nice progressive scan resolution. If you shoot in 24p Advanced, it saves 24p complete frames within the 30 frames laid to tape. That why you can drop the extra frames, and will have 24 distinct and whole frames to work with. Trust me on this one. [hr][/blockquote]
That's it exactly. I've worked with both, and Advanced is much better all around. You don't have to de-interlace anything at all, which means you don't lose any fidelity or vertical resolution.. you simply drop the unneeded frames. Advanced is the only way to make sure you maintain FULL progressive frames.

Of course, if you're intimidated by the more complex frame layout of Advanced, or you don't really care about deinterlacing your footage, then you might as well go with Standard. Your loss.

 

Here's the difference... Skip to the part in red if you want the succinct direct and easy answer.

Both 24p formats use what's called a "pulldown" to store 23.976 frames of information in 59.94 interlaced fields, which compose the 29.97 frame rate of NTSC video. Working in integers, 24 fps goes into 30 fps exactly 1.25 times. This means for every 5 frames of 30p you have 4 frames of 24p.

Suppose your 4 frames are labeled ABCD. Each frame is composed of 2 fields, for example Au (frame A - upper field) and Al (frame A - lower field). If you had a perfect 24p system the upper and lower fields would be combined to a true progressive image, which would be progressively scanned. If however, you had a 48i (48 interlaced fields) display, then the display order would be like this:

Al_Au_Bl_Bu_Cl_Cu_Dl_Du (lower fields first). To save time, this is usually written AA_BB_CC_DD.

If we had 48i or 24p displays, it would be this easy. Alas, we don't (really!). By contrast, we do have 60i or 30p displays, for which we can easily display AA_BB_CC_DD_EE. So we have two extra fields in a 60i broadcast.

24pA uses a 2:3:3:2 pulldown. Our fields get presented as follows: AA_BB_BC_CC_DD. You'll note here that the middle frame contains no new information, and can easily be discarded. Furthermore, all of the actual 24 frames are stored in a nice progressive image and no further manipulation is required. However, you end up with 4 nice frames and the a junk frame if displayed a 60i, that gives an extra bit of jitter on playback.

24p uses a 2:3:2:3 pulldown. This dime the fields are presented as: AA_BB_BC_CD_DD. You'll note here that frame "C" does not exist anywhere as a full progressive frame. As a result, the C frame has to be reconstructed by plucking it's fields from two seperate frames, and recompressed - and inherently lossly - or at least more computationally intensive process. As far as I'm aware, almost all DVDs with 24p content carry this pull-down, as motion rendition is perceptually smoother.

So... If you have a camera that does both of these (currently the DVX100/a/b, and Canon XL2) then you have a choice. If you are interested in doing any frame-accurate 24p editing or effects work, you should shoot 24pA. Discarding frames is computationally simple, and doesn't affect the quality. When exporting something rendered in true 24p after shooting 24pA to DVD, simply add the 2:3 pulldown and you're done. If you are interested in recording the footage straight to DVD with no editing or effects whatsoever shoot 24p, and the process will be painless.

-Spiff

 

Shooting with the tape rolling at 30fps and only recording at 24 fps would reduce the motion blur, and therefore wouldn't have as much of a film look. Wouldn't it?

 

Shutter speed = motion blur. Not frame rate.

-Spiff

 

What would it be with 25p footage? There isn't any pulldown, right?

 

There are no pull-downs in PAL land. Shoot 25p, play 25p. Shoot 24p, speed up by 4% to 25p. Shoot 25p, slow down 4% to 24p. Pitch-shift audio to keep it in line. Simple.

-Spiff

 

Theres a difference between 24p and 24fps. Just because you shoot 24p doesnt mean you are going to be working with actual 24fps. You still have 30 frames. Just look on a 24p able camera like a DVX or XL2. 24fps is actual film and does actually have 24 frames moving through that second.

 

24fps is actual film and does actually have 24 frames moving through that second.

I'm really curious as to what's preventing them from making a digital camera like that.

 

Dorkman, that is an inaccurate statement about 24p Advanced. The ONLY reason that there is a 24p Advanced is to recover all 24 distinct frames that were recorded at full progressive resolution. You must shoot 24p Advanced if you want to preserve maximum image quality of all 24p frames.

Also, I believe Preimere Pro will capture 24pA and then drop the extra frames for you, and then leave you with a perfect 24fps video to work with.

 

Learn something new every day. Sounds like Advanced is the way to go.

AE since version 6 can also remove advanced-pulldown footage, and usually do a pretty bangup job of guessing the phase.

M. Scott

 

The ONLY reason that there is a 24p Advanced is to recover all 24 distinct frames that were recorded at full progressive resolution. You must shoot 24p Advanced if you want to preserve maximum image quality of all 24p frames.

If the codec were uncompressed, Pixel's argument falls apart. The reason this statement I copied is true is that the DV codec is adaptive - it analyses each frame it receives and decides based on content whether to compress it as interlaced or progressive. Naturally, it will pick progressive encoding if the images are progressive, but when a frame is split across frames, it's likely to use the interlaced form and compromise image quality a bit.

-Spiff

 

Spiff, I wasn't talking about compression. I was talking about interlaced frames. If you shoot 24p standard, you end up with some the frames split in two and recorded to tape; from which you could never recover the 24 full resolution orginal frames. With 24p advanced, it spaces the 24 frames apart, in their full resolution, without splitting them in half. Then it records them to tape. Then with Premiere, Avid, or Final Cut, you can recover the complete, full resolution, original 24 frames.

Dorkman, I appologize if my previous post sounded like I was stepping on your toes, so to speak. I was just trying to make sure that he knew that he must shoot 24pA if he wants to edit a true 24fps timeline. I didn't mean to call you out, I'm sorry.

 

I was talking about interlaced frames. If you shoot 24p standard, you end up with some the frames split in two and recorded to tape; from which you could never recover the 24 full resolution orginal frames.

You're incorrect. A 2:3 pulldown CAN be reversed to recover the original frames... I do it all the time. The problem lies entirely in compression and the difficulty in recovering the original frames... but trust me: it can be, and is, done by many tools, including After Effects.

-Spiff

 

Wow, I didn't know that. Cool.

 

How would I benefit from slowing 25p down to 24p? In the end I have to speed it up again anyway to be able to watch it on TV. I guess one frame doesn't make a difference in terms of the look.

 

There are two good reasons if you had PAL you would want to do the 4% slow-down to 24p.

#1. If you were going to do a film-out.
#2. If you were going to do an NTSC release (in which case you slow down to 24p, and then add a 2:3 pull-down to get a 60i signal).

There's a third option too - which is if you're obsessed with pleasing people who think "give me 24p or give me death"... which you should bless with the later, given their over-zealous devotion.

-Spiff

 

No, not at all. I was unclear regarding the benefits of 24pA and so it's good to have it clarified.

M. Scott

 

Eh, may be late with this reply, but 24 advanced is for if you intend to transfer to film. That's why it's made, otherwise just use regular 24p.