4K video problem

[potwnc]

Although I am rendering to 60p, I'm getting 59.94 fps. Is there no way to get 60.00 fps? 60p typically means 60.00, doesn't it?

[Lin Evans]

It's a long story, but 59.94 is double the 29.97 fps commonly called 30 fps. Most digital cameras actually use 29.97 fps even though they call it 30 fps often in the manuals. It's a hold over from  early TV days where a combination of the frequency of the electrical supply (60Hz) and the amount of broadcast “bandwidth” that was available to the first color analog TV signals worked out to 29.97.  Likewise the 60 fps from most digital cameras is actually 59.94 fps. 

It could be actually changed, but keeping the frame rates the same is easier than the math it would take to make them actually 30 and 60 fps. At least that the way I understand it.

Best regards,

Lin

[jt49]

All in all, I am not very happy with the present situation. The said problem is not a 4K problem, and I would not regard it as solved. It seems to be true that 60 often means 59.94, but not in all cases. I often receive videos that run at 30.00, and I would like PTE to offer video export at 30.00 and 60.00, as well (like other AV programs). Like many others, PTE uses x264, and this encoder supports 30.00 and 60.00 (and many others). So it should not be a big affair for PTE to offer additional frame rates.

[Igor]

Yes, technically it's possible.

But do other professional video editors offer both options - 60p / 59.94 and 30p / 29.97, or not?

I didn't find true 30p option in Adobe Premier. Only 29.97. See the screenshot.

It seems that most video footage is being recorded in 59.94 and 29.97.

If we add both options, don't you think that it may confuse users which option is more correct?

Proshow also records in 29.97 / 59.94

[Lin Evans]

If there is some advantage to 30fps and 60fps I'm not aware of it myself. Anyone who has information why it would be advantageous to have also 30fps and 60fps please let me know. 

Best regards,

Lin

[davegee]

Could it be that in the case of the other Poster regarding Time Lapse he thinks there is some advantage in having 30fps so that he can input 30 images for every second of Video.

Maybe it does not work that way - but perhaps that is the way he is thinking?

DG

[jt49]

Photoshop offers 29.97, 30.00, 59.94, and 60.00, and so does Wings Platinum! Most of my club members use WP, so I often receive Videos at 30.00.

[Lin Evans]

But, is there some advantage of 30fps and 60fps over 29.97 and 59.94?  If so, what is it?  Photoshop, though having video capabilities, is not a dedicated video editor nor is Wings Platinum.  Photoshop also offers 23.976 fps as well as 24fps but really, is there any advantage or is it just numbers?  I can not visually see any differences between 59.94 fps and 60 fps myself and I seriously doubt if anyone can. Does a video rendered at 30 fps and played back at 29.97 fps look any different in reality?   Are we just playing with numbers because there are so very many different frame rates out there, where does one stop?  Does it make any serious difference whether we have a true 30 and 60 fps rate when the vast majority of videos are rendered at 29.97 and 59.94? Does having 30 and 60 fps for Photoshop somehow make Photoshop more useful for video than Adobe's flagship dedicated video program Premier? 

Convince me! 

Best regards,

Lin

[jt49]

I don't have Premiere on my computer, but I am pretty sure that Premiere will be in the position to render at 30.00 and 60.00 (the same will hold for Final Cut). Igor's screen shot from a tutorial on Premiere does not show the drop-down menu for possible frame rates, but a menu for often used presets. If you look at this list, you will not find 30.00, but you will see 23.976, a frame rate that seems to be recommended for Instagram. Unfortunately, PTE does not offer 23.976. Why not? X264 is able to render at 23.976. I also looked at videos at YouTube. Most YouTube videos seem to be rendered at 25.00 or 29.97, but I also found examples at 30.00 and 60.00.

So again, my question is: Why doesn't PTE offer the frame rates that the underlying encoder (x264) is capable of?

[David Porter]

Not that I know much about video but reading this thread I guess the reason PTE does not offer it is that there is no advantage in it. If you think there is please say what it is.

Mickp.

[Igor]

Let me think more on this question (30p, 60p). I have nothing against more frame rate options. Just I want to make the choice more simple, because two similar options may confuse many users.

Regarding 23.976. In all versions of PTE, if you choose 24p, PTE will render 23.976 video. This can be checked in MPC-HC player (technical info about a video file).

[jt49]

7 hours ago, Igor Kokarev said:

Let me think more on this question (30p, 60p). I have nothing against more frame rate options. Just I want to make the choice more simple, because two similar options may confuse many users ...

This is what I said here, it might cause problems for some users. But I think that this problem could be solved by offering appropriate presets, and showing all kinds of frame rates only in the custom mode.

I know several people who tend to produce their AVs now using video editors. On the other hand, some AV competitors advertise with video editing. Some time ago I thought about a discussion on "video editing with PTE" in my user group. But I changed my mind because of missing features.

[Barry Beckham]

I think it worth keeping an eye on the average user who just wants to drop a video into their presentation and have it work. I am suggesting that the vast majority of users want the process to be this easy and if it’s  not. Rightly or wrongly they will blame PTE

I can’t help but think of KFSD here, let’s not make adding video any more complicated than it already is.

 

[Tonton Bruno]

Please, Keep It Short and Simple.
My suggestion is to limit the choice only to the following items:
24
25
30
50
60
Add a note to precise it is only Progressive and the exact values are 23.976, 29.97, etc.
Add a second note stating that advanced users who want to use other parameters have to first generate the project and then convert the frame rate to any other value using ffmpeg, and give them a link to a help file countaining several examples of command lines.

[jt49]

9 hours ago, Tonton Bruno said:

....
Add a second note stating that advanced users who want to use other parameters have to first generate the project and then convert the frame rate to any other value using ffmpeg, and give them a link to a help file countaining several examples of command lines.

Can you explain this in more detail ?

[Tonton Bruno]

Yes I can !

 

Assume you generate à video at 29.97 fps with a duration of 10 minutes (600s).

This represents 29;97*600=17982 frames

You ask ffmpeg to transform this video to a video at 30fps without changing the frames.

The new duration is 1782/30=599.4s. You lost 0.6 seconds on 10 minutes, that is to say nothing.

The audio file will be automaticaly modified and reduced of 0.6s without chaging any sound.

Doing that, you will obtain a video at 60fps, and if you need absolutely a duration of 600 seconds, you will have to add 18 blank frames at the begining or at the and of your clip.

I presume you can perform this transformation under Premiere or Davinci Resolve, if you prefer.

[Barry Beckham]

I am not knowledgeable about video so I don’t really understanding why I need to know this? Are there some quality or performance issue that goes along with this and if there are, can anyone explain them. 

 

[jt49]

2 hours ago, Tonton Bruno said:

Yes I can ! ...

Thanks. I have thought that you were thinking of re-encoding, but I wanted to be sure about it. So let us look at an example. Think of a project including a few videos, all at 30.00 fps. The output should be a video again. Any program that wants to be regarded as a serious tool for video editing would now offer me the same frame rate as the input videos. Rendering the new video at 29.97 fps, and re-encoding it afterwords to 30.00 fps can not be accepted as a professional workflow.

It is not a new observation: There a people who make their suggestions for new versions. But in cases of suggestions from others (which may not match their interest) they discredit them, pretending to care for the average user or the KISS principle. If we would restrict PTE to what the average user needs, we had to cancel many of PTE's existing features. In this case, I had to look for something else. But I'm sure that this will not happen.

 

[Tonton Bruno]

3 hours ago, jt49 said:

Any program that wants to be regarded as a serious tool for video editing would now offer me the same frame rate as the input videos. Rendering the new video at 29.97 fps, and re-encoding it afterwords to 30.00 fps can not be accepted as a professional workflow.

I use Davinci Resolve 15.
It is one of the best professional tool for vidéos and movies.
Davinci Resolve works as I described.
You include in your media pool all the necessary clips, created with different frame rates and when you include one of these clips in the timeline, it is adjusted to the output settings of your project.
When there is a slight difference in frame rate, like 29.97 instead of 30, there is no frame calculation, just a change of the duration of each frame, as I suggested you to do for PTE.
If you sart from 24fps to go to 30 fps, some extra frames are added by duplication each 5 or 6 frames randomly, and in some cases, it is visible.
Transforming 24 to 30 fps is not a good solution from a professionnal point of view, but transforming 29.97 to 30 fps has no impact, even on a professionnal point of view.

 

 

[jt49]

You did not understand my argument. I'm not interested in Davinci Resolve. I only ask for additional frame rate parameters for PTE, a feature request that could be easily fulfilled, as the underlying encoder offers the appropriate functionality 

[Barry Beckham]

It's a little disappointing not to receive any answer my question above, but perhaps the perception is it's not a genuine question. Well, I can assure you it is and I am willing to be educated by those who know video. My guess is others may also like some clarity too

If I have a 4k Video and the properties say its 24fps and assuming I just trim the video length a bit and then output that via Photoshop and retain 24fps

Does that video still play at 24fps within a video I have exported from  PTE at 60p?

Or are approx 2 frames created for every one originally there and the original video is now playing at 60p?

 

[Lin Evans]

Barry, 

It will play at 59.94 fps but will be no better in animation smoothness than it was at 24 fps as far as I know. There will simply be approximately two frames for each original frame but the motion is not any smoother because of a higher frame rate. The original capture rate determines the smoothness and making about two blurred frames for each original doesn't change the appearance. Igor can correct me if this is wrong.

Best regards,

Lin

[Barry Beckham]

Lin

Thanks for the response. I can understand the motion will not be smoother with the higher frame rate applied when outputting an Mp4 from PTE.  I can carefully view the results and I see no difference that I can identify. Where another question arises is this:

Tonton said that If you start from a 24fps video and go to 30fps, some extra frames are added by duplicating each 5 or 6 frames randomly. That in some cases, it is visible. If it's going to be visible from 24fps to 30fps, wouldn't it be worse at 60fps and why don't I see that? I am only viewing one 4K video where the movement within it is fairly smooth, its not fast action, so perhaps that may make a difference.

 

 

[Lin Evans]

Hi Barry,

Logic would say that it should be worse going from 24 to 60 (12 frames less difference than three times 24) than from 24 to 30 (six frames ) but unless there is sufficient animation probably it won't be noticeable. I don't have the diagnostic equipment to test it, but I recall Igor saying that he doesn't recommend using videos at significantly lower frame rate in a show output at 60 fps because of the possibility of "jerky' motion. Then there is the issue of whether the video was converted to AVI and how that might impact things. On my 32 Gig Win 8.1 i7 system things which are jerky on my Win XP with maxed out RAM (under 4 gig usable) are ultra smooth and they each have about the identical video card. I also notice that even in an exe file where I have some motion such as elliptical motion of the moon in orbit around a masked video of a rotating Earth, there is a point in that sequence where the moon animation "jerks" a bit. It's completely repeatable but on my Win 8.1 high end system it's as smooth as silk. I can run the animation as a single slide on the XP and it's also as smooth as silk but when that identical slide is copied and pasted in a show with other significant animation, it's jerky at exactly the same point every time. When I run the same exe on the Win 8.1 system it's again as smooth as silk. So what I gather is that perhaps the additional RAM and superior OS is buffering more and the XP is RAM challenged perhaps because the cache isn't dumped and renewed.  This may also account for differences in what some see versus what others see with video when a slower frame rate is played inside a 60fps video. What I'm getting at is that it may be that differential resources might account for what some see as jerky video while other see ultra smooth video. I've also found that some players handle 60 fps very well while others apparently struggle.

It's not a simple thing but hopefully when version 10 is released many of these issues and problems will be solved if only by virtue of better use of resources and more dependency on hardware rendering for video. One can only hope...

Best resgrds,

Lin

[Tonton Bruno]

1 hour ago, Barry Beckham said:

Tonton said that If you start from a 24fps video and go to 30fps, some extra frames are added by duplicating each 5 or 6 frames randomly. That in some cases, it is visible. If it's going to be visible from 24fps to 30fps, wouldn't it be worse at 60fps and why don't I see that?

If you film a cartwheel at 24 fps with the shutter at 1/48s or 1/50s everithing will be OK if you visualise the video at 24 fps.
If you use a shutter speed of 1/125s or 1/250s the weel rotation may be jerky, accordind to the rotation speed of the wheel.

Now if you film a cartwheel at 24 fps with the shutter at 1/48s or 1/50s, then convert it to 30 fps, the rotation of the wheel will look correct but slightly less fluid.

Il you convert 24 fps to 60 fps, you will obtain the same fluidity than for 30 fps, or may be it will be more fluid depending of the conversion algorithms.

But if you use a shutter speed of 1/250s, the conversion to 30 or 60 fps may create something realy jerky. This is that I call a visible drawback.

To sumarise, if you follow the 180° rule (shutter speed must be half the frame rate), that is to say 1/50s for 24 fps, 1/60s for 30 fps, 1/125s for 60 fps, you will not have problems after conversion, even if you film a cartwheel or a drummer in a concert.