1080 24pA Firestore import question?

B

borax

Active member
Hi,

I just imported my first batch of footage from a Firestore and want to make sure that I did everything correctly.

On the HVX I was shooting 1080 24pA footage which I thought would interpret to true 24p native footage when I imported into FCP with "remove duplicate frames" preference checked.

What I ended up with was the footage vid rate being 23.98fps and the compressor setting of DVCPRO HD 1080i60 and the frame size of 1280 x 1080.

Is that what I will alway get with the 24pA setting?

If the remove duplicate fames option was checked why wouldn't I end up with 24 individual frames? What would happen if that wasn't checked?

Can I take the conversion a step forward and convert to 24pN? Why 23.98?


I am just a bit confused with the base concept of 24pA, and need a quick intro.
Thanks
 
Compressor will always read 1080i60, that's just the compressor engine FCP uses, that's not a problem. The Vid Rate shows what your real FPS are, and they look correct. In NTSC world, 24 is what we call it for ease of conversation, but it realy is technically 23.98 frames per second. Just like 60i really is 29.97 frames per second, that are made up of 60 interlaced fields per second (2 fields make up 1 full frame).


When the 3.0 firmware upgrade for the FS-100 goes public, it'll do Native modes, and the pulldown won't be needed. Heck, it's gonna do QuickTime Native, so you don't have to use the P2 Import window in FCP at all!

But what you're seeing is correct, nothing to worry about, you do have 24p footage.

I'd also highly recommend Barry's HVX book and DVD. Very worth the investment!
 
BenB said:
Just like 60i really is 29.97 frames per second, that are made up of 60 interlaced fields per second (2 fields make up 1 full frame).
Click to expand...

Not quite! That should read the other way 'round.
29.97 frames per second is REALLY 60i fields per second. As it never really displays one complete frame at a time. The fields are evenly distributed in time on the screen, so the odd and even fields are never really on screen together to make a complete frame.
 
Thanks Ben,

I was just freaked out when I saw the 60i compressor.

So basically even when I shoot 720pn my vid rate will show 23.98?

I assume that the quicktimes I imported have the extra frames removed? and if I didn't have the remove duplicate frames checked I would have ended up with a vid rate of either 60i or 29.97?

As for the Firestore, I can't wait for the upgrade. From what you are saying it sounds amazing!!

Quicktime native would be awesome!! Now all we need is an upgrade so that it will rotate the footage from an 35mm adapter.
 
"29.97 frames per second is REALLY 60i fields per second." Yes, that is exactly what I stated.

2 feilds of 60i make up 1 frame of the video. Yes, they are flashed on a TV screen that way, but do you edit each feild seperatly? No, becuase in DV we put the two feilds together to make one full frame. Measuring fields is fields, measuring frames is frames, two interlace fields make up one frame, 60 interlaced fields a second make up 30 frames per second. What I said is correct.

60i won't show up as a Vid Rate, as it is a statement about the measurment of Fields. The Vid Rate would show up as 29.97, which is the measurment of frames, and often called 30fps.
 
BenB said:
"29.97 frames per second is REALLY 60i fields per second." Yes, that is exactly what I stated.
Click to expand...

That is not quite what you stated. Your statement was the other way 'round, you said "60i is really 29.97fps"

BenB said:
What I said is correct. 60i won't show up as a Vid Rate, as it is a statement about the measurment of Fields. The Vid Rate would show up as 29.97, which is the measurment of frames, and often called 30fps.
Click to expand...

Not quite because 60 interlaced fields does not always make for a 29.97 frames per second vid rate. Go and shoot something at 720p/24p (not pn) or 720p/30p or 720p/60p for that matter and see what the vid rate is in the import P2 window.
 
Ok, ozduc, now you're confusing things, comparing apples to onions.

60i equals 29.97fps interlaced, period.

24p is not interlaced, nor is it 60i, nor is it 30fps. Apples and onions...
60p is not interlaced, nor is it 60i, nor is it 30fps. Apples and onions...
30p is not interlaced, nor is it 60i, but it is 30fps. Apples and onions...
 
BenB said:
Ok, ozduc, now you're confusing things, comparing apples to onions.

60i equals 29.97fps interlaced, period.

24p is not interlaced, nor is it 60i, nor is it 30fps. Apples and onions...
60p is not interlaced, nor is it 60i, nor is it 30fps. Apples and onions...
30p is not interlaced, nor is it 60i, but it is 30fps. Apples and onions...
Click to expand...

Ok Ben, sorry I didn't mean to confuse things. Mentioning the different 720 formats was just to illustrate that 59.94 can show up as the vid rate, albeit a progressive format.
However I still stand by my statement that 60i is not really 29.97fps, but 29.97fps is really 60 interlaced fields per second.
In both the 480/24p/24pa and 1080/24p/24pa modes, those 23.98 frame rates are recorded into a 60i stream of video on the DV tape/P2 card or P2 card respectivley, or Firestore but they are not recorded at 29.97fps.
Maybe I am not explaining what I am getting at very well, so I will quote from Barry's book that you recommended borax should read.
Page 29. 1st paragraph:

"And interlaced video runs at 60 fields per second (technically 59.94 fields per second in NTSC/ATSC) NOTE: NTSC video does not run at 30 (or 29.97) "frames" per second - that's an unfortunate misnomer that's been associated with NTSC from the beginning. It actually works at 60 (or 59.94) "fields" per second. Two fields do not make up a "frame" because the fields are equally spaced in time........Field two is as far away from field one as it is from field three. Fields are not "grouped together" in NTSC video; rather each field will spend as much time on screen with the field that precedes it, as it will with the field that follows it......."
 
So, you edit "fields" in your NLE, not "frames", right? So where does the 29.97 fps come from if there are no "frames" at all?

Barry's discription is technically true, and exactly is how the signal its "trasmitted" and shown on a TV's interlaced system. But we're talking about the digital files on a computer that can not show fields, only progressive frames. One reason some folks see interlace artifacts on their computer monitor that don't show up on a TV or external NTSC monitor. See, you're correct about the transmission of the signal, but we're talking about the actual digital files and editing. Then you have frames, and two interlaced fields, one dominant and one, well, "submissive?", make up a signle frame.

You're playing with symantics here, just drop the whole subject.
 
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BenB said:
When the 3.0 firmware upgrade for the FS-100 goes public, it'll do Native modes, and the pulldown won't be needed. Heck, it's gonna do QuickTime Native, so you don't have to use the P2 Import window in FCP at all!
Click to expand...

For 1080 24p too? I thought the upgrade was only for the 720p modes.
 
JesterJJZ said:
For 1080 24p too? I thought the upgrade was only for the 720p modes.
Click to expand...

Yes you thought right! The upgrade is for 720 native modes only, NOT 1080/24p.
In 720 mode the HVX scans and can record up to 60 progressive fps, however although the HVX scans the image progressively in 1080, it has to record it in a 60 interlaced stream, so a pulldown will still be required, even with the FS-100.
So your 24p frames per second are sliced up and spread out over 60 interlaced fields using a 2:3 (24p) or a 2:3:3:2 (24pa) pulldown.
So contrary to what some people are led to believe 60i, is not always 29.97fps.:evil:
 
I originally said the FS-100 3.0 upgrade will do any Native mode the HVX will. So, is there a 1080 Native mode on the camera? No, simple as that.

And just for the record, let me quote Barry's book, page 160, "Each field is equivilant to half of a video frame, either the even lines or the odd lines." The frame rate of 60i is 30 (29.97) until AFTER the pulldown removal process takes place and removes the flagged frames. But before the pulldown removal takes place in the NLE, it's 60i, which is 30fps, because each "frame" we deal with in our NLE is made up of two fields of the interlace stream.
 
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