Shoot 29.97i or convert for deliverable?

[R Neil Haugen]

I have a proposed upcoming project under early discussions. It's for a non-profit,  where the more likely destination is client web use. But, if possible, it would be pitched to public TV.

Local public uses NPB standards, everything in 29.97i drop-frame. Of course that's 59.94.

That would not be my primary choice to shoot in. But I know a workable practice has been shoot 24p, edit, then take to Ae and do 3:2 pull-down.

Is that still the best thing, other than shooting in interlaced?

[Richard M Knight]

You could shoot 59.94P

[Ann Bens]

If they want interlaced > shoot interlaced.

[Remote Index]

Hello R Neil Haugen,

I think your proposed workflow is best and will give you most long term flexibility.

I suggest shooting 23.98p or 29.97p and doing a conversion at the end or their specific delivery requirements. (I haven't used AE to do conversions before.)

R.

[R Neil Haugen]

Thanks for those responding ... but perhaps I'd also like @Jarle Leirpoll , @Warren Heaton , and @Michael Grenadier to opine? I do like a range of experienced thoughts. The more the merrier ...

[Michael Grenadier]

Just finished a pbs cutdown.  I was told to deliver 29.97, but the piece was mastered as 24p   Gonna see if 24p will be accepted...  I've mentioned this to the client, but as usual, radio silence.   Not sure what the best way to add pulldown to make it 29.97...    If I remember correctly not a simple process to get the best quality, bwdik...   

[R Neil Haugen]

Back in NAB 2019 dev Wes suggested using Ae to do that 3:2 pull-down. But that's four years back now ...

[Michael Grenadier]

I remember exploring this in AE and couldn't get an unequivocal "this will give you the best quality."  This is the first time I'm actually outputting the deliverables to pbs.  Always would use an online house that had the experience to make sure everything was to spec and if the crack engineering stafff at pbs kicked it back, would either fix it or school the engineers...  But it's a brave new world.  

[Michael Grenadier]

found this from Warren a few years ago

https://community.adobe.com/t5/premiere-pro-discussions/23-976-to-29-97-conversion-2-methods-yield-d...

Warren usually knows what he's talking about...  

[Warren Heaton]

If it's 100% for public access, shoot i29.97, edit i29.97, finish i29.97.  If a web version is being created, it can be deinterlaced for p29.97 web/social media.

However, if you shoot 23.976, edit 23.976, then export to 23.976 first and then do 3:2 pulldown on that to finish at i29.97.  Web/social media exports would just be exported to p23.976.

If it's most likely for web with a hope of public access, I'd lean toward 23.976.  That said, if this was going to my local PBS station, I'd take the time to talk to someone at the station.  It's likely to be important that the show be slated as "29.97 3:2 pulldown" assuming a five second or longer slate is included at the head of the tapeless delivery.

[R Neil Haugen]

Good comments all. That whole drop-frame thing being something I have no experience with. So timing is definitely a concern.

[Remote Index]

Michael Grenadier,

Just a quick note to draw attention to the fact that the linked process (by Warren re: After Effects) assumes a 23.98 original. There's no speed change happening in After Effects, so you'd still need to get your 24fps orig to 23.98fps before the AE process. (Unless there's something in AE to address that which I'm not aware of.)

R.

[Michael Grenadier]

Thanks, but the master is 24p (aka 23.976).  That seems to be the standard shooting frame rate at this time.. at least for the docs I'm working on...  

[Remote Index]

Michal Grenadier,

You know your master, but I can assure you that 24fps is not 23.976fps. (Though I do believe there was a time when some camera menues conflated one with the other.)

R.

[Michael Grenadier]

In my understanding, 24p is not 24 fps.    it's 23.976.  https://en.wikipedia.org/wiki/24p.   Unfortunately these terms are often used improperly...  and there is some ambiguity about this as you can see in this wikipedia article...   And you'll see 29.97 fps called 30 fps, improperly in my opinion.   Neil, in his initial post clearly is talking about 23.976.   But it's always important to be clear in how you use the terms and using 24p (and adding 23.976 to the description) can not hurt.  

[Remote Index]

Interesting.

I think at best "24p" is ambiguous as to frame rates (ie. used to refer to both 23.976fps and 24fps).

First I will note that the wikipedia page seems quite dated. (example: "Some 24p productions, especially those made only for NTSC TV and video distribution" ... using NTSC as a foundation misses a lot in 2023.) Premiere Pro (and other NLEs) are straddling a lot of standards, but some good references would be ATSC and DCI which encompass broadcast and theatrical in the U.S. and beyond.

It's true that I assumed 24fps is indicated by the "24p" formulation - which is presumptuous since he has only indicated progressive frames but not frame rate. But by such logic I must assume that "24p" does not communicate any frame rate information at all (or rather, only narrows it to either 23.976fps or 24fps).

It's also true that there's a lot of informal shorthand re: 24 vs 23.976 and 30 vs 29.97 frame rates ... but in a forum post about mastering and frame rate / format conversions, it's safe to assume that precision is necessary. (I don't see how you can make meaningful recommendations or decisions otherwise.) Thus my interpretation of Neil's post, your post and careful qualifer on Warren's (very useful) AE instructions.

I'll add that later formulations of formats (example: 1080p24, 1080p23.98) were clearer in communicating frame rates and also suggested an interpretation of the (I believe etymologically earlier) '24p' which I seem to have taken on. (In case it's unclear, 1080p24 unambiguously communicates 24fps).

"Neil, in his initial post clearly is talking about 23.976."

I did not interpret it that way - nor would I with any such correspondence. This was reinforced by his references to 29.97, 59.94, an to pull down (though again 'pull down' has been widely adopted in a sloppy way as well).

R.

[Warren Heaton]

Let's see.

When summarizing video settings, like 1080p24, its frame size which is followed by the scan method which is followed by the frame rate.

"p" stands for progressive scan; however, with modern displays that have a refresh rate rather than a scan rate this is a holdover from CRT displays.

"i" stands for interlaced scan.

p23.976 (also called p23.98 and p24) is a valid frame rate and can be pulled down to i29.97 or i30 which can be pulled up to p23.976 with full cadence.  Cadence refers to the pattern used to convert whole frames to interlaced frames.  There is no i23.976.  

p24 is a valid frame rate and can be pulled down to i29.97 or i30 for finishing.  It's not meant to be pulled up.  There is no i24.

p25 is a valid frame rate.   In the early days of digital video, it was popular for shooting video and then printing to film.

i25 (also called i50) is a valid frame rate.  Using "25" favors frames and using "50" favors fields.  It's usually associated it PAL and SECAM.

i29.97 (also called i59.94, i30, and i60, and once in a blue moon i29.976) is a valid frame rate.  Ideally, it would just be called i29.97 with no rounding.  It's likely drop frame timecode (dftc) but can be non-drop frame timecode (ndftc).  It's usually associated with NTSC.

i30 (also called i60) is a valid frame rate.  It is often non-drop frame.  It's usually associated with NTSC.

The frame rate for NTSC and the frame rate for PAL/SECAM are both supported by ATSC.

p29.97 and p30 are valid frame rates, but these should be avoided if possible for source footage.  They are better suited to being a result of deinterlaced i29.97 or i30 when exporting.

p47.952 (also called p47.96 and p48) is double p23.976.  This is usually best used for MOS (without sound) b-roll.  This has the temporal resolution to play at half speed (slow motion p47.96) without frames being interpreted.

p48 is double p24.  This is usually best used for MOS (without sound) b-roll.  This has the temporal resolution to play at half speed (slow motion p24) without frames being interpreted.

p50 is double p25 and is sometimes called and sometimes called "frames for fields".  This has the temporal resolution to play at half speed without frames being interpreted.  It also provides full frames that can be interpreted as fields for i25.

p59.94 (also called p60) is double p29.97 and sometimes called "frames for fields".  This has the temporal resolution to play at half speed for without frames being interpreted.  It also provides full frames that can be interpreted as fields.

p60 is double p30 and sometimes called "frames for fields".  This has the temporal resolution to play at half speed without frames being interpreted.  It also provides full frames that can be interpreted as fields.

High frame rates like p120, p240?  Like any of the higher frame rates are great for b-roll without sound.  They have the temporal resolution to run at lower frame rates without interpreted frames.

Drop and non-drop timecode (which can also be written as "time code") are unique to 29.97 and 30 or multiples of it.  With drop frame timecode, two frames are renumbered every minute except for every tenth minute to keep pace with a real-world clock.

How does one pick a frame rate?  Delivery settings.  If you have to deliver i60 (but really i29.97 because someone rounded up), then your source footage should be i60 and your edit settings should be i60; however, your source footage could also be p23.976 or p24 using 3:2 pulldown later - but do not mix and any of these if you want your show to pass quality control.  If you have to deliver p23.98 (but really p23.976 because someone rounded up), then your source footage should be p23.976 and your edit settings should be p23.976.

Why do frame rates get rounded up when it's a cause of so much confusion?  Good question.  There's the desire to simplify things.  30 is easier to write than 29.97 and 24 is easier to write than 23.976.  It's up to us to know that 480i60 is the same as 480i29.97 and the same as 480i30 and the same as 480i59.94.  It's also up to us to know that p24 might really be 24 but could be p23.98 which is really 23.976.

What else?  I've seen changing from 23.976 to 24 be called "pull up" and changing 24 to 23.976 called "pull down"; however, those are just frame rate changes and the terms in this context should be avoided because pull down is, by definition, 23.976 or 24 to 29.97 or 30.

[R Neil Haugen]

Thanks for the detailed post!

[Michael Grenadier]

I remembered that back in the day shooting with a panasonic dvx100, what panasonic called 24p, was clearly 23.976.  Of course, I found the manual online and they said 24p was 24 frames per second which in this case, it is NOT.    I also think I remember that gopros originally shot 24 fps and then they changed it to 23.976 but still called it 24fps.    Lot's of confusion here...    

[Warren Heaton]

Yes, it's a bit of a mess.

The Panasonic AG-DVX100 was groundbreaking for the time!

[Remote Index]

Thanks for the breakdown, Warren. Lots of good info.

However, there’s some confusion in your language regarding pull up and pull down. It is not accurate to say “pull down is, by definition, 23.976 or 24 to 29.97 or 30” as it’s has a wider adopted usage (particularly with regard to audio) by which it more meaningfully defines “pull up” (through inversion).

It’s possible the term ‘pull down’ comes originally from electrical engineering, but it more likely comes from the claw action of film cameras and projectors. It was first used in television when confronted with 24fps film and was used in the formulation ‘3:2 pull down’, encompassing two processes (the creation of fields and the speed change from 24fps to 23.976fps).

Since that early history, the term ‘pull down’ is now used to refer to introducing the above field cadence whether or not a speed change is necessary (as you have detailed), and also specifically to these speed changes (in audio post) - meaning the speed changes that have been made on picture and therefor the speed changes necessary for audio to remain in sync. ‘Pull down’ as a speed change is particularly important in audio post discussions, and is the only context in which ‘pull up’ can be made sense of.

(I have never encountered the term ‘pull up’ used to refer to a format conversion by which interlaced material is made into progressive - would be very interested if you have a specific reference / link to anything, anywhere that does).

I’ve never found a good reference for the history, but there’s a good reference for audio implications (with a handy chart!) here, which includes this summary: "An audio pull up or pull down is needed when there is a frame rate change on the picture that affects its length."

In considering this in an audio post context, one can start to make sense of pull up (from 47.952kHz to 48KHz, or from 48kHz to 48.048kHz, for example) and pull down (from 48.048kHz to 48kHz, for example)

Again, there’s common usage which loosely refers to any field-deriving process - but being aware of the (also widely used) speed change meaning is important.

R.

[Warren Heaton]

Pull-down comes from moving film down through the transport mechanism during the telecine process.  The Standard Handbook of Video and Television Engineering by Jerry Whitaker and Blair Benson has very detailed diagrams of the process.  It is also discussed in the After Effect User Guide > Importing Footage >  Importing and interpreting video and audio.

Thank you for pointing out that referring to reverse 3:2 pull-down as "pull up" can cause confusion.  I'll try to use the proper name rather than slang in the future.  It also gets called reverse telecine or inverse telecine.

Removing 3:2 pull-down is specific to i29.97 footage that has 3:2 pull-down present in the first place and restores the original p23.976.  The process does not apply to footage that is i29.97 to begin with.

[Michael Grenadier]

and removing pulldown can be a tricky process particularly if you don't know the correct cadence AND assuming that there haven't been any edits done of the 29.97 material.    AE (and I think Premiere) allows you to remove pulldown if it can successfully figure out the cadence which is NOT always possible (the voice of experience speaking).    What's interesting is many dvd players can remove pulldown and play out progressive 23.976 footage if the pulldown flag is set properly when encoding the film.