Is 1080i/24p interlaced or not?

I

iocomposer

Member
I apologize in advance if this is a moronic question, but I wonder if someone here would please help me understand this: Doesn't the i in 1080i mean that it is interlaced footage? And does not the p in 24p stand for progressive? Clearly there's a gap in my understanding of HD terms here... How can you have both i and p in the same footage... and is the footage interlaced or not?

:dankk2:
 
1080i/24p means the camera is shooting 24 progressive frames per second, then recording, via 3:2 pulldown, the 24 frames across a 60i interlaced stream. You can then use a non-linear editor to remove the pulldown, so you end up with 24 frames/sec progressive. This is done because certain formats, such as NTSC video and DVCPRO 1080i do not allow progressive video, so in a way, this is a cheat that allows 24 frames to be recorded in a 60 field video stream, much the way film is converted to video. To sum up, yes it's progressive footage recorded on a interlaced format. Hope this helps.
 
Thanks for that explanation! I think I do understand it now.... so FCP is actually using the 60i frames to get the necessary information to sandwich it down to 30 or 24 progressive frames, essentially just deinterlacing the footage by gluing the fields together, correct? So you can get truly progressive 1080p @ 24 or 30fps with this camera... or is it somehow not TRUE progressive 1080p because this is a cheat?
 
It's true progressive 1080p. What happens is that the camcorder has to "disassemble" it to package it into the interlaced recording format. And FCP "reassembles it" to its original pure 1080p glory when you import it.

Just make sure to use 1080/24PA, not 1080/24P mode.
 
This camera just gets cooler and cooler the more I learn about it.

Thanks for the tips (in addition to the wealth of knowledge you've already given me via your DVD).

Now here's my last question (I promise!)... how do you set up FCP to automatically do this on import? Does it automatically import the footage to the current sequence's settings or is there some sort of hidden settings area in the P2 import window that I have yet to discover?
 
You just have to setup the timeline for the footage. So you shoot 1080i/24pA , then in FCP when you get the footage from the P2 card. You have a timeline in FCP that is 1080i/24pA, when you drop the footy into the timeline, that deinterlacing magic to reassemble the footage happens and is played back in such.
 
You guys are so amazingly kind and helpful.... I really appreciate it. I realize I should probably be reading the FM, but I've been having a heck of a time hunting down this information.... and you guys have a way of putting it so concisely.

So if I'm understanding you correctly, it's not actually doing anything to the resolution of the footage on import... you still get the full 1080i/60i footage put on the disc, it's just doing its conversion magicly when you put it in the sequence timeline set to the different resolution/framerate settings.
 
FCP packages the footage in 23.97 fps quicktime wrappers when you use the P2 import. There's no sequence setting for "24pA" as such. It'll just be a 1080 DVCPRO HD timeline (FCP has a preset for this--use it to make sure you have the compression and pixel aspect ratios right). Set the framrate for 23.97 fps and you should be good to go. A good litmus test is that if FCP tells you to render your footage before you even do anything to it, then there is a discrepency between the timeline and the footy.

Hope it helps.
 
rapsucks said:
There's no sequence setting for "24pA" as such.
Click to expand...

i may be mistaken, im kind of confused i guess. but there is an easy setup in FCP for 1080i/24pA

1176101294.png
 
There is a 24pA preset for capturing off of a DVX or HVX tape. But when you do the P2 import, FCP removes the pulldown for you. The only important step is to set your sequence to align with the footage.
1176102506.jpg
 
Again, if you're pulling footage off of a P2 card, then you don't need a pA setup--you only need to be sure that your sequences are set appropriately. As Cynic pointed out, 5.1.4 has a 1080 24pA easy setup that calibrates sequences and capturing. If you don't need to capture, then just set the sequences using the DVCPRO HD 1080 24 fps setting in the sequence setup.
 
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