29.97i vs 29.97p

Karsten Schlüter wrote: ...Would be a nice read, if you would share some memories from 25y ago ....
and not that cryptical please as at finalcutprofi.de ...
reminded me way too much of Kai Krauses weird byteburg blogs .... :silly:

... what happened to that guy, anyhow? hmmmm.....

(massive threadjack in progress!!)

Hmm, I tried to make a new topic with this, but something prevented me from doing this: ???...selected bb code can't ...???

I don't know what happened to Kay. He used to show up on my tiny little booth on several expos: "Hi Andreas, I have something new, I invited some journalists to show up here on our booth later today. Can I place the refrigerator in the back?"
I heard that quite often. The last time he did, he left w.o. the frigi sent me several emais about work in progress and news about his castle. Those stopped some day. I still have the refrigerator

Hmmm, äääh, tja: finalcutprofi.de
I feel ashamed. I haven't solved riddles about the 'james stewart' and 'vertigo' things.

Once about that time mentioned I got an email from Charles Wilt at Apple, which was something like: "hi andreas, we got a new industry contact about integrating some more 3d stuff in qt. as you are more familiar with 3d as i am would you like to join me, him at a public discussion on qt at the xyz games expo in cannes?"
Following weeks there were several emails forth and back, but I never got the name of the person mentioned.

Arriving in Cannes I got the company and name:
Vertigo a Vancover/CDN based company spezialized in MotionCapture.
Contact name: James Stewart

Thought it was a joke - but wasn't.
When I first time went to the hotel he was staying the bell man thought I was joking when I asked for James Stewart from Vertigo

Best
Andreas

duusfcp wrote: ...I've shoot a short interview with Sony NX3 (1080 29.97i / 48Khz) and iPhone 6S+ 1080 30p / 44.1Khz)...When I imported both file I've noticed that the Sample rate and the frame rate are different so I've conveted iPhone clip to (1080 29.97p / 48KHz)...What's the difference between 29.97p and 29.97i?...is the difference only the fields?...if so, do I have to worry about sync?

Your HXR-NX3 shoots 24p, 30p, 60i and 60p (Sony's nomenclature). For brevity 30 often means 29.97 and 60 means 59.94 (frames/sec). However 60i means 59.94 fields per sec (29.97 frames/sec). Your iPhone 6S+ shoots 1080p at 29.97. Yes it is confusing.

So your NX3 likely shot 1080i/60 (59.94 fields/sec or 29.97 frames/sec) and your iPhone 1080p/30 (29.97 frames/sec). Those are actually the same frame rate so no problem conforming them in the editor.

If your project is progressive (ie 1080p/29.97) then the interlaced content will be deinterlaced according to some algorithm -- generally NOT discarding every other field. There are many different deinterlacing algorithms, including blend, mean, Bob, linear, Yadiff, etc. I don't know which one FCPX uses but it's effective.

If your project is interlaced then the progressive content will be interlaced, maybe using an algorithm like Progressive Segmented Frame. I don't know what FCPX uses: en.wikipedia.org/wiki/Progressive_segmented_frame

Your project type including resolution, frame rate and interlace/progressive by default is determined by the characteristics of the 1st clip added to the timeline. This can be overridden by selecting File>New>Project, and selecting Custom.

Ideally you want to shoot everything as progressive. However converting from progressive to interlaced happens regularly in the broadcast world. The US ATSC high-def standard is 1080i/29.97 at 59.94 fields per sec, so anytime you see movie content that was originally shot at 24 fps it has been interlaced at some point for compatibility with the ATSC transmission standard, plus 3:2 pulldown for frame rate conversion. Your TV likely deinterlaces this, and it generally looks pretty good.

ABC, Fox, and ESPN capture and broadcast in 720p/60 (59.94 frames/sec) but some network affiliates upscale and interlace that to 1080i @ 29.97 frames/sec or 59.94 fields/sec.

If video was designed today it would never use interlaced format -- that was a legacy of phosphor persistence on CRT TVs (which still existed when the ATSC standard was devised), and also other broadcast infrastructural equipment.

I don't think there is much data bandwidth difference between 1080i @ 60 fields/sec vs 1080p @ 30 frame/sec. They are both transmitting 30 frames per second. In theory each 1080i field could be totally different from the adjacent field which means the same amount of data would be being transmitted as 1080p/30. 1080i @ 60 fields/sec does have a higher bandwidth requirement than the other ATSC standard of 720p/60, which is why for several years in the initial high-def rollout, 1080i was restricted to 1440 horizontal pixels due to equipment limitations.

Re your audio question I have normally had no problems with different audio sample rates.

Fortunately the new upcoming broadcast standards don't have an interlaced version. All progressive. How we deal with old interlaced footage in a progressive world is the headache that Ben was referring to. The best results I have found is just to "interlace" inside the progressive framerate. That is each field (say 1920x540 is blown up to 3840x2160 individually. Run the UHD at 60 frames per second and it should look fine. This gives a much better result than regular deinterlacing. I've run 480i content in a 1080p 60fps stream and it looks much better than deinterlacing the 480i with some filter or just losing half of the resolution completely. You can still notice the interlace flicker doing it this way but in my opinion it achieves the better result.

Ummm...What? :blink:
I just trust FCPX to handle that stuff for me. If I run into problems, I then run to the engineers in our department.