Phase out fractional frame rates!

ahalpert said:
It's hard to think of something that matters less than the difference between 23.98 and 24
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It's more of a difference than just the mathematical difference in the written numbers suggest. They might as well be two different formats, like PAL or SECAM. Maybe I"m a little more in-tune with things like this, shooting a lot of broadcast/networks stuff and having to actually feed video in, and if it is not in the format(frame rate and rez) that they require, it can be a major issue, to the point that they cannot accept it (their receiving equipment does not see it or does not see it correctly) and it will have to be run through a "standards/cross converter" and converted to what they can handle.
 
jmone said:
Sorry! I was trying to point out that in any argument about (potentially) changing standards for acquisition, distribution, consumption needs to have a global context. For us PAL users we have always been stuck with trying to mix and match frame rates and unless there is an exact multiple / division you see the pull down judder - this is all a PITA.

We have three main groupings currently around the globe, 23.976/24/25fps, 59.94/50fps and then for "fun" you also have your 29.94. Seems to me 23.976/24/25fps could all be folded into one integer frame rate, then higher frame rates should be a clean multiple of that. We are no longer bound to timing being driven by the frequency of the power delivery in houses.
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One of the networks here has been running a lot of UK originated programming over the last several years(seemed to increase during 2020/covid) and even at that level, the conversions can be pretty bad. Several of the shows that are obviously originated in 25P and then converted to 24/23.98 and shown here in the US, have a "jump" that looks like a frame being dropped every second, which makes everything "jump" forward in time. Very jarring and annoying as a viewer.
 
Run&Gun said:
It's more of a difference than just the mathematical difference in the written numbers suggest. They might as well be two different formats, like PAL or SECAM. Maybe I"m a little more in-tune with things like this, shooting a lot of broadcast/networks stuff and having to actually feed video in, and if it is not in the format(frame rate and rez) that they require, it can be a major issue, to the point that they cannot accept it (their receiving equipment does not see it or does not see it correctly) and it will have to be run through a "standards/cross converter" and converted to what they can handle.
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But basically you just need everybody to be on the same format, whichever it may be?
 
Run&Gun said:
One of the networks here has been running a lot of UK originated programming over the last several years(seemed to increase during 2020/covid) and even at that level, the conversions can be pretty bad. Several of the shows that are obviously originated in 25P and then converted to 24/23.98 and shown here in the US, have a "jump" that looks like a frame being dropped every second, which makes everything "jump" forward in time. Very jarring and annoying as a viewer.
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Yup it is butt ugly. The are probably doing a frame doubling / deinterlace to get the original to 50fps, then doing a 1:1:1:1:2 pulldown to get it into NTSC frame rates. You should see not frame drops but frame repeats in this method. The other (more traditional) option is to do a 4% speed down (and then a pitch correction for the Audio) to get 25fps --> 24fps then the usual 3:2 Film to NTSC pulldown. Not only do you have pull down artefacts but the show now runs 4% longer. For us in PAL land, the opposite was used for films to PAL, a 4% speed up. At least the movie was over a bit quicker but there was no pull down dirty frames.
 
Run&Gun said:
One of the networks here has been running a lot of UK originated programming over the last several years(seemed to increase during 2020/covid) and even at that level, the conversions can be pretty bad. Several of the shows that are obviously originated in 25P and then converted to 24/23.98 and shown here in the US, have a "jump" that looks like a frame being dropped every second, which makes everything "jump" forward in time. Very jarring and annoying as a viewer.
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“Playing back 23.976 at 23.976 is fine, no problem. However, playing back 24.000 at 23.976 results in a dropped frame every 41 second – some refer to it as "micro-stutter". Most people do no see it but it is one of those things where if you notice it, it gets hard to ignore. And playing back 23.976 at 24.000 results in a duplicate frame every 41 seconds”. - FlatpanelsHD
 
I think people who minimize the issue of fractional frame rates have had little to no experience in the global broadcast field. Yes, it would be nice if everyone involved in a particular acquisition/post/transmission chain were on the same page and they need to be if the process is to work. But the devil is in the details.

One thing that is holding back any progress on standardizing frame rates is legacy equipment and the huge amount of archived programming that would need converting for use in an integer world.

JMHO.
 
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stoneinapond said:
I think people who minimize the issue of fractional frame rates have had little to no experience in the global broadcast field. Yes, it would be nice if everyone involved in a particular acquisition/post/transmission chain were on the same page and they need to be if the process is to work. But the devil is in the details.

One thing that is holding back any progress on standardizing frame rates is legacy equipment and the huge amount of archived programming that would need converting for use in an integer world.

JMHO.
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I agree. I started in this business at a time when it was a HUGE deal if someone made the mistake of shooting 30(29.97)ND instead or 30(29.97)DF or vice-versa. There are a lot of people on here that edit their own stuff and as individuals, are very nimble and can adjust fairly quickly and easily to correct mistakes or deal with something non-standard or otherwise different, so they may not fully realize just what a big deal some of the things are to these big production companies, post houses and networks that they think(or really) are trivial. And trust me, a lot of things make me scratch my head when I hear that post can’t handle format x, or post has to have y this specific way.
 
Run&Gun said:
Exactly. Which is more or less what they are proposing by phasing out the “redundant” and no longer technically necessary frame rates.
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But you could equally phase out 24 in favor of 23.98? Neither one has an advantage right? They're essentially the same thing?

For those like myself who don't feed into a broadcast pipeline, the internet is pretty forgiving. I just have to worry about timebase consistency within a project. And even then, you can get away with some mixing and matching (certainly lots of 60fps into 24p when you use it in real-time instead of slow motion)
 
ahalpert said:
But you could equally phase out 24 in favor of 23.98? Neither one has an advantage right? They're essentially the same thing?
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This is pretty much the argument which was applied when the entire concept of fractional frame rates was developed in the first place, and the last seven decades of technical workarounds demonstrates more than adequately that no, they are emphatically not the same thing.

As people have said a lot on this thread, it works perfectly fine so long as you're one organisation feeding one outlet. If you're just producing stuff to play on your phone, you can work at seventeen and two-thirds frames per second if you really feel the need. Early (colour) NTSC broadcasting couldn't possibly have cared less, because all they were doing was live production from midday to half past and exactly how many frames that involved was a matter of supreme irrelevance.

Encounter almost any other situation - audio sync, editing, let alone programme interchange with environments operating at other frame rates - and life becomes very complicated.

I posted some actual working code earlier in this thread which should make it clear just how much extra complexity this can involve.

P
 
This is pretty much the argument which was applied when the entire concept of fractional frame rates was developed in the first place, and the last seven decades of technical workarounds demonstrates more than adequately that no, they are emphatically not the same thing.
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If we are (hypothetically) reducing the number of frame rates in the wild and are all agreeing to abide by a new, shorter list of standard frame rates then it's not a foregone conclusion that we would choose 24 over 23.98 fps. I think that's the point he's making.
 
Andy9 said:
If we are (hypothetically) reducing the number of frame rates in the wild and are all agreeing to abide by a new, shorter list of standard frame rates then it's not a foregone conclusion that we would choose 24 over 23.98 fps. I think that's the point he's making.
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Right. It's not like we could tell the difference between which is which by just looking? Or that one plays better with 60hz or something? Or that 24.00 is somehow more cinematic?

Of course, it would make sense for the sake of simplicity to choose 24.00 over 23.98. But I could easily argue that we should phase out integer frame rates so we can all use 23.98 because it's more common as of now
 
Any conversion that is not a clean multiple from source (say 23.976) to display (say 59.94) involves dirty/dropped/repeated frames. While conditioning for NTSC viewers think this look "fine" it really is not.

In reality, the existing library of content is all sorts of frame rates and I doubt that the situation will change going forward. The other solution is to more widely adopt display rate changing. I do this on my HTPCs and some HW Players (like a Playstation) also has the option. My player automatically changes the display's frequency to match that of the content. No dropped / repeated / dirty frames. It's great! ... but there are a couple of limitations to this approach:
- Non Integer Frame rates can be hard to dial in, but you can usually get it drop / repeat free for at least a couple of hours before it drifts
- I know of no universal way for "Auto" detection & changing for streaming / web services (so I have to manually switch). If you are a Netflix user, you can see what the frame rate is of the encoded media by pressing ****+Ctrl+Alt+D .
- I know of no Phone / Tablet that can change display rate but then on such a small screen it is less of an issue as it is more casual viewing where quality is already compromised
- It does not address the issue of mixed frame rates in a timeline
 
ahalpert said:
I welcome them to abandon PAL
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Join us PAL users! We are 85% of the world. FYI - the ATSC supports PAL frame rates.... but the spec "bans" the use of PAL frame rates in 60hz countries and bans NTSC frame rates in 50Hz countries.
 
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