Is 24fps correct, or is it 23.976 when movies are done?

[zerowalker]

Okay the topic sounds like it does, but well the thing i want to discuss is.

24fps movies/series etc.

As many of you may know, most of the Series/movie in NTSC are done in 23.976 for various reasons. However, the fact is that the original maybe 24fps.

For example. In a Cinema, everything is pretty much 24fps, that´s the "Cinema FPS". All countries pretty much agree on this.

So, if a movie is recorded and done for a Cinema, then it will be done for 24fps.

However, when that movie is released on other Media like DVD, it will most likely be in 23.976, meaning it has been slowed down.

You may know that PAL pretty much does this with everything, but that´s more of a region matter. NTSC is a bit more complicated, as from what i can understand, you can´t know if the movie was produced in 24fps or 23.976.

So you can´t know which is correct, meaning you may as well be watching a slowed down or sped up version.

What i want to know is if there is way to know this. I am guessing that everything is made in 24fps, and it´s changed to 23.976 for compatibility reasons. And a movie is never actually produced in that (ignoring self produced movies).


I hope you get what i am trying to explain here, though i see that i did a pretty bad job.

But please post your thoughts or facts, i am quite interested.

And for the record. I know that 24fps and 23.976 is not something to really care about, as it´s less than 1%, but that isn´t the matter here, a difference is still a difference not matter the case.

Thanks:)

[raffriff42]

In the context of modern HDTV, both are correct High-definition television: Standard frame or field rates ('https://en.wikipedia.org/wiki/High-definition_television#Standard_frame_or_field_rates') (Wikipedia)

ATSC table 3 defines the following frame rates for digital high-definition television in the US. These formats are also available within the DVB broadcast standards used elsewhere in the world. 23.976 Hz (film-looking frame rate compatible with NTSC clock speed standards)
24 Hz (international film and ATSC high-definition material)
29.97 Hz (NTSC standard-definition material)
59.94 Hz (ATSC high-definition material)
60 Hz (ATSC high-definition material)
In addition to the ATSC standards, the DVB Group defines the following frame rates for use with the various DVB broadcast standards: 25 Hz; may be used with any frame resolution; may use interlaced or progressive scan.
50 Hz; defined for use with 720p and 576p only.
The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source.EDIT - Broadcast facilities in NTSC countries are locked to 59.94 Hz for SDTV; they would have to have a non-synchronized relationship between their SDTV and their HDTV operations if they were to broadcast HDTV at 60 Hz. This adds needless complexity and expense, especially if they want to simulcast SDTV and HDTV.

[TheSkiller]

However, when that movie is released on other Media like DVD, it will most likely be in 23.976, meaning it has been slowed down.
You may know that PAL pretty much does this with everythingTo go from 24 to 23.976 you slow down, correct. But from 24 or 23.976 to 25 you speed up.


I think it is pretty safe to assume anything shot on actual real film is shot at 24 fps and also edited in 24 fps as long as it's a movie production, rather than a TV production.

Anything shot digitally (like with a RED epic)... I guess it mostly depends on whether it's a TV production or a movie production to be shown in cinemas. For TV there's no reason to shoot in 24 fps if you have the choice of 23.976.


I know you said this is not about the difference, but I can't resist to show you how tiny the difference is.
So let's assume a movie in 24 fps with a length of exactly 90 minutes.

After slowing it down to 23.976 (more precisely it is 24000/1001), the length has changed to

89 minutes and 54.6 seconds. Difference is 5.4 seconds.

[filler56789]

So let's assume a movie in 24 fps with a length of exactly 90 minutes.

After slowing it down to 23.976 (more precisely it is 24000/1001), the length has changed to

89 minutes and 54.6 seconds. Difference is 5.4 seconds.

Hmmm, but if the framerate is lower, the playback time should be greater, and not less :)

Instead of doing "5400 seconds X (24/23.976)",
you did "5400 seconds X (23.976/24)".

[zerowalker]

So, you agree that probably all "Real" movies are 24fps?

And yeah, in PAL it will always be a speed up from NTSC no matter what.
But it´s even worse from my understanding.

For dubbed stuff that hasn´t been on the Cinema. It will be a double edged sword from that dubb.

It´s probably done like this. PAL country get a movie that´s NTSC. They are going to dubb it, and then release it for DVD (which will also contain the original language).

The dubbing will be done in 25fps. Meaning, they speed it up, Then they dubb. So, the dubbed language will have the voices correct in 25fps, but the Music/Effects wrong.
And if you slow it down to NTSC it will be the opposite, meaning you will never be able to get them both right for dubbed version.

This is probably how everything is done sadly. From TV Series to Movies.
The only ones that are correctly dubbed, will be those that are dubbed For Cinema, only then will everything be done properly.

Though, that´s not really a problem for those who don´t care for dubbs. I however do in most cases, so just wanted to point out the hell PAL/NTSC has done for this;P

Back to topic, as you say, it´s indeed a 1000th slower, and is nothing you could ever notice, you can only see it in the length, if you can hear it, you aren´t human.
But i get frustrated by it, there is always something wrong going on thanks to all this stuff. I really hate how NTSC has done this and how it´s sticking around.
As 23.976 and 29.97 etc, isn´t even needed any more, it was just for the changes to Color to stabilize the carrier or something i think.

And thanks to it sticking around, it´s just a mess where it can either be 29.97 or 30, or 59.97 or 60, or 23.976 or 24.

While it can just in reality be 24 30 60, no need for the "hackish" way to prevent collision anymore. But the same goes for PAL, though PAL itself hasn´t got any problem, it´s always 25 or 50, it always messes up everything by speeding it up.
There are some rare cases where they haven´t sped thing up though and have the same speed. Though in those cases they are skipping/blending frames. That however has solved the dubbing procudure good enough.

I think the only cases are when it´s a movie/series that´s in 29.97. As then they can´t slow it down (29.97 to 25 is to large), so the only real solution will be to skip/blend frames.
Though it´s very rare cases, as most stuff that´s 29.97 is actually 23.976 after deinterlacing or something (really bad with all those stuff, but it was something like that i think).

[wonkey_monkey]

I've seen some movies converted to PAL with very high quality audio resampling (Stardust) to maintain pitch (if you have the PAL DVD, compare the commentary track to the main audio, especially over the end credits), but conversely I've also seen some done very very badly (Spiderwick Chronicles on Film 4).

[zerowalker]

Pitch correction is extremely rare sadly. I do however notice that they use it on Disney Channel for example nowadays from some tests.
I think they actually did a pitch correction then dubbed, if so that´s very nice.

But if you look at movies and DVDs etc, it´s extremely rare, no matter if it´s dubbing, or just a movie conversion.
I don´t really get why you even need to speed it up, just add 1 frames every second. Sure it may look a bit stuttery if the TV is displaying 50hz, but nowadays everything is 60hz, so 24 or 25 shouln´t be any different.
But then again PAL has a higher resolution, so it´s stuck at 50hz as 60hz isn´t compatible with it. Hopefully the Digital era will solve this, but it will probably take some 10 years until they get rid of the PAL NTSC and just go into the "1080p,24p etc" stuff.

[TheSkiller]

I don´t really get why you even need to speed it up, just add 1 frames every second.
You haven't watched such a conversion then yet – the repeated frame every second is very obvious and very annoying. Simply no option.
There is however "Euro Pulldown" which does this but with fields instead of frames, so you do 24 fps to 50 fields per second. This gives you a slight stutter (1/50th of a second) every half a second, quite watchable, unlike one repeated frame per second. Speed stays the same of course.

Sure it may look a bit stuttery if the TV is displaying 50hz, but nowadays everything is 60hz, so 24 or 25 shouln´t be any different.
Nowadays everything is 60 Hz? PAL terretories are and will probably always use 50 Hz. Displaying 60 Hz is no problem for the most part, but you cannot flip a switch and say "well, let's never use 50 Hz again".

Hopefully the Digital era will solve this, but it will probably take some 10 years until they get rid of the PAL NTSC and just go into the "1080p,24p etc" stuff.The only things the digital era will solve is getting rid of analog color modulation differences (PAL vs NTSC color), and the same resolutions for HD, but not the same frame rates (for obvious reasons).


@ filler56789
Oops, you're right. It is the other way around. Nevertheless the difference is 5-6 seconds for a 90 minutes movie.

[Mole]

In 10 years time I hope at least 48fps will be the norm. Hopefully 60fps or more.

[zerowalker]

You haven't watched such a conversion then yet – the repeated frame every second is very obvious and very annoying. Simply no option.
There is however "Euro Pulldown" which does this but with fields instead of frames, so you do 24 fps to 50 fields per second. This gives you a slight stutter (1/50th of a second) every half a second, quite watchable, unlike one repeated frame per second. Speed stays the same of course.

I have seen such conversions, but in the end, 23.976 to 25fps with added frames, will look like 23.976. The thing is 50hz, which causes the stutter effect as it´s not dividable to 23.976. Look for example on a PC, all PCs are 60hz, or 120hz etc.
But still you can´t watch 24fps 25fps etc just fine. Sure 15/30/60 will look smoother, but it´s not heart breaking.

Nowadays everything is 60 Hz? PAL terretories are and will probably always use 50 Hz. Displaying 60 Hz is no problem for the most part, but you cannot flip a switch and say "well, let's never use 50 Hz again".

What i meant with "60hz" was that everything nowadays is compatible with it. The problem was more in the Console era, where 50hz was messing up everything, as you may all remember from PS2/GC/XBOX and before, now it doesn´t matter, except for some unique cases i guess.

But as you say, there is no way to simply just stop using old stuff like 50hz, or 23.976 instead of 24fps. But that´s the problem. They should try at least to change it step by step. But if you look at it, nothing has even changed at all since the 80s. The only thing that has changed are Games/Consoles. Bluray does however ignore this matter thankfully, though there exist 50i versions but they are rare from my understanding.

So hopefully when DVD and such are ignored and a Universal Media is taken on, the problem won´t exist in that way. Though the Television will probably take extremely long time to make some Universal standard, as it´s not as easy to change as a Media standard which are "alternative" to people. Television is a "Must" and should work for everyone, even if you sit on a 90s TV, hence the problem.

The only things the digital era will solve is getting rid of analog color modulation differences (PAL vs NTSC color), and the same resolutions for HD, but not the same frame rates (for obvious reasons).

Yes and no, the digital era will as you say, solve all the PAL and NTSC drawbacks from an analogue perspective.
But it will also solve some frame rate cases.

Though it´s complete, it´s just for BD and Games for now. Where BD has 24p which everyone agrees on more or less (no 25 special edition), though they exist i think.
Games also as i said with Consoles, now there isn´t something like 50hz edition/mode, it´s just 1080p with 30fps, or something like that. So special broadcast edition for that Country.

But as you say, it will not really solve much, even if it ignores the problems from the past, it will still exist for many years to come.


In 10 years time I hope at least 48fps will be the norm. Hopefully 60fps or more.

Couldn´t agree more. I have been looking at some very old camrecorded stuff i have, and those are in 50i. And the difference from 25 to 50 is amazing, though the Resolution isn´t though;P

[SeeMoreDigital]

nahh.... I think everything should be captured at 50 fps ;)

[BigCondor]

I just want to let you know that many BDs sold here in Hong Kong are made at 24 fps!

[zerowalker]

nahh.... I think everything should be captured at 50 fps
Well 50fps works for me, if you compare it to 24 or 25:)

Though one thing i think it pretty ironic when it comes to PAL and NTSC is this.

In movies PAL is faster than NTSC and have bigger resolution, meaning, it actually beats NTSC in that matter, (Though PAL is pretty much YV12 while NTSC is YUY2, so it loses there).
But in Games and i guess some movies(50/60i), PAL is Slower, as NTSC has 60fps while PAL has 50. So it´s the other way around, though we still have the higher resolution (which actually does make a huge difference in games, sadly it´s rare that games actually use it as NTSC is the global one).


I just want to let you know that many BDs sold here in Hong Kong are made at 24 fps!

Ah so they are not 23.976fps?

I find it interesting that it actually exist both on the BD world. 24p is a full compatible solution now, so 23.976 doesn´t even need to exist for BD.
But still it does exist. And i even think it can depend on Releases, meaning for example.

A movie released in USA can be 23.976, then the same movie released in China can be 24fps.
Not totally sure about that though, but i think it can be like that.

[Guest]

In movies PAL is faster than NTSC False. The NTSC frame rate is 29.97 and the PAL rate is 25.

and have bigger resolution True.

Though PAL is pretty much YV12 while NTSC is YUY2. False. Actually NTSC and PAL are analog interface specifications, and in the analog domain there is no chroma subsampling. Even if you talk about MPEG2 encoded streams, they both typically use YV12 (4:2:0).

[nhakobian]

in the analog domain there is no chroma subsampling

There may not be something exactly like digital chroma subsampling; however, NTSC, PAL (and even SECAM), have significantly narrower chroma bandwidths compared with the luma channel. PAL additionally has to directly interpolate chroma information from line to line to maintain color phase stability (while NTSC's is adjustable with the hue control).

Since this is analog processing, its unclear just how much lower the effective color resolution is, and its even further complicated by the fact that noise and phase errors during transmission can affect it as well.

(Used http://en.wikipedia.org/wiki/PAL#Colour_encoding and http://en.wikipedia.org/wiki/NTSC#Color_encoding as references to double check my facts.)

[zerowalker]

False. The NTSC frame rate is 29.97 and the PAL rate is 25.

True.

False. Actually NTSC and PAL are analog interface specifications, and in the analog domain there is no chroma subsampling. Even if you talk about MPEG2 encoded streams, they both typically use YV12 (4:2:0).

Well except for those cases. but i am sure that like 99% of the stuff is 23.976. But indeed the regular is 29.97(30) and 59.97(60).

And yes i know that there isn´t any YV12 YUY2 etc.

But the way both NTSC and PAL works, makes it very similar.
PAL does pretty much have subsampling like YV12, as it discards every other chrome line all the time. And all Analogue material is often comparable to YUY2, but you can´t really put Digital and Analogue side by side anyway.

[Guest]

I tried to straighten you out but you continue to talk nonsense. Have it your way.

[zerowalker]

What do you mean, which of it is nonsense?
That most movies are in 23.976, or that NTSC is "YUY2" and PAL is "YV12"?

[burfadel]

Originally Posted by zerowalker
In movies PAL is faster than NTSC

False. The NTSC frame rate is 29.97 and the PAL rate is 25.

Quote:
and have bigger resolution

True.

Quote:
Though PAL is pretty much YV12 while NTSC is YUY2.

False. Actually NTSC and PAL are analog interface specifications, and in the analog domain there is no chroma subsampling. Even if you talk about MPEG2 encoded streams, they both typically use YV12 (4:2:0).

Actually PAL is played faster than NTSC, despite PAL being at 25 fps and NTSC at 29.97.

The reason for this is that the 29.97 isn't a real 29.97, it is made up for 3 real frames and 2 mixed frames, in place of 4 real frames. 23.976 and 29.97 work perfectly in ratio, such that 23.976 is exactly 0.8x 29.97 (hence, 4/5 the framerate). This higher framerate means that the video effectively plays at the equivalent speed of 23.976, but displays 29.97 frames. This does not come free though, 29.97 fps NTSC is terrible in motion, so PAL is the winner despite being sped up around 4 percent. Also, PAL has a higher vertical resolution and better colour range (without that NTSC tint issue), so yet another win for PAL.

I don't know about that YV12 PAL vs YUY2 NTSC thing, but I can assure you PAL has crapload better colour than NTSC.

The issue with PAL is a almost all of the PAL disks that were originally filmed with NTSC in mind are not transferred from the originals, but from the NTSC transfer (but at 23.976 sped up). What this means is, PAL versions of NTSC TV shows etc are upsampled (from 480 lines to 576 lines), and you are still limited by the limitations of NTSC colour.

[zerowalker]

Yeah that was what i meant. NTSC is almost always played at 23.976 eventually, after deinterlacing or whatever. While PAL always is 25.

What i meant with YV12 and YUY2 is simply that PAL is pretty much like NTSC but by discarding every other chroma line (very roughly explained), so it will have less chroma resolution. And that way is very similar to YV12, meaning if you capture PAL, which will be at YUY2 as with much of analogue material. You can just Discard every other chroma line(blend them) and then convert to YV12. There is no need for the YUY2 resolution as it doesn´t have that capacity. While NTSC has it.

But as you say, NTSC has issues that PAL has solved, but none of them are perfect. But PAL doesn´t have the tint issue (i know about it, but haven´t really seen it first hand so can´t say anything about it), but the price is less chroma resolution.
But from what i understand PAL is made after NTSC, so they made it better than NTSC by solving the disadvantages.

So in the end, if you ignore the FPS problem, PAL is surely the superior one, even with the less chroma resolution, as Luma has much more importance than Chroma.

Though off topic, i would really like to see YUY2/YV16 in the future media/television. YV12 is a bit to low in the Chroma, as it´s half, it´s pretty sick when you think about it. But for movies it doesn´t really have much impact, especially if you sit far away which you should do most of the cases. It´s small details that get´s totally blured out, a good example would be colored text.

Though i think YUY2 is sometime used in broadcasts when i think about it. Not sure if it´s just a carrier though, and it´s YV12 upsampled or something.

[TheSkiller]

Broadcast production has been done and stored in 4:2:2 YUY2 since Digital Betacam was introduced in the early nineties. The older analog formats such as Betacam stored YUV which would be equivalent to YUY2 as well.
The whole production chain is in 4:2:2 or even 4:4:4 until the video is encoded on the fly for broadcast, be it analog or digital.
It's only us lowly consumers who have to deal with YV12.


What zerowalker and nhakobian said about comparing NTSC's color "subsampling" to YUY2 and PAL's to YV12 is correct, it's not nonsense, although we can agree that these terms obviously don't belong to analog color modulation schemes, but it's a good way to explain it.

PAL delays every other chroma line to mix it together with the previous one. For analog TV transmissions this and a few other quirks completely remove any tint errors from the color and turn them into faint and pretty much invisible saturation errors. Because every other chroma line is mixed with the previous one, you get something similar to color subsampling (similar to YV12 indeed).

The NTSC color scheme does not do this, every luma line's chroma is left untouched. This does indeed result in color subsampling similar to YUY2, but at the infamous expense of tint errors, and also more severe Y/C separation issues (more pronounced dot crawl and rainbowing) in composite video signals.


In 50+ years of analog TV transmissions, PAL's technique has been superior, but as soon as we're talking about an absolutely stable and clean signal, like from a game console, the chroma delaying technique doesn't help (except for Y/C separation) and is actually destructive, plus there won't be any tint issues in such a scenario anyway, making NTSC better in this regard – ironically.

Anyone who doesn't believe me should try this: connect a source with no inherit chroma subsampling to begin with (first choice: game consoles) preferably via S-Video. Have it display something colorful in PAL, and then in NTSC color modulation. You will see the difference in color "subsampling".

[zerowalker]

Vere thorough written. And that does explain it. I did know that all analogue material and much broadcast is YUY2, but that confirms it.
Not surprised that the end user suffers, as most doesn´t even care as long as there is a picture and audio more or less.

Anyone who doesn't believe me should try this: connect a source with no inherit chroma subsampling to begin with (first choice: game consoles) preferably via S-Video. Have it display something colorful in PAL, and then in NTSC color modulation. You will see the difference in color "subsampling".

Not completely sure what you mean with "color modulation". But i guess you just mean that system, the NTSC color system vs PAL color system on the console?

I have actually used a console with both PAL and NTSC, sadly i haven´t used real S-Video if my memory doesn´t fail me. PS2 and Xbox only have Composite, and the S-Video is simply a cheap "composite as S-Video" which just introduces a checkmate articats all over the place.

However, even with Composite, i must say that NTSC from my memory at least, was more colorful. While PAL had much lack in saturation compared to it.

What zerowalker and nhakobian said about comparing NTSC's color "subsampling" to YUY2 and PAL's to YV12 is correct, it's not nonsense, although we can agree that these terms obviously don't belong to analog color modulation schemes, but it's a good way to explain it.

Well that´s good, was confused if i had totally messed up something. But indeed i do not compare them side by side. Analogue and Digital can´t be compared like that anyway. But in simple terms they act similar as both have lesser Chroma following YUY specifications more or less.
Can´t say anything about VHS/DVD etc though, as i don´t have anything like that in NTSC.


Also, about the PAL chroma shifting. It seems that there isn´t exactly any given rule about it.
The idea from it was that the line that was out of place, would be blurred by the Human Eye as a CRT simply scans and scans all the time, and the human eye will simply try to make a picture out of it. And if something it out of place, it will try to "discard" it to make the picture whole.

That however breaks when you get to still images and non-crt. So the solution there is different depending on the manufacturer or something i guess. But the end result is that they will simply discard/blur it as the human eye won´t do it anymore.
So it´s quite a delicate way they made it.

However when capturing, there are some cards that doesn´t do anything with the lines, making everything intact. And that makes it look very bad, there is Green/Orange lines all over the place on saturated areas.
Though of course that is easily solved by doing what should be done, blur them out.

[real.finder]

so if the original was film then the 23.976 has changed in the audio pitch?

and if the original was film and we have TeleCine 29.970 then it done by 24 to 23.976 with change in the audio pitch then TeleCine to 29.970?

[foxyshadis]

Yup. The post-production studio will slow both down (usually using the original, uncompressed audio, not the AC3/DTS/SDDS) by 0.1% and encode it. I don't know of any that would try to pitch-correct it and drop frames, it's such a tiny deviation.