60fps video mixed with 24fps video - help!

Report · Dec 30, 2016

Hi all,

I know that this has been asked possibly many times before, but I simply cannot find a solution to this. I'm getting jerky-looking (or incorrectly playing) 60fps video on my project timeline...

I have a timeline with a mixture of 24fps clips and 60fps clips. Now, the 60fps clips are definitely recognised as being 60fps by Premiere (so it tells me in the clip properties) but when I go to "sequence" and click on "sequence settings" it's telling me the timebase is 24fps.

As a test I created a new project and just pulled in one of my 60fps files and I checked the "sequence settings" and it said the timebase was 60fps. It played perfectly and smoothly.

So something is not right in my project and I don't know what it is...the 60fps video are a bit jerky on the timeline so I don't know what is going on.

There must be a way to seemlessly use both 60fps and other frame rates in one project, but obviously I am doing something wrong.

Thank you in advance.

Al.

Report · Dec 30, 2016

There must be a way to seemlessly use both 60fps and other frame rates in one project

There is. The 24 fps material will play back in real time, the 60 fps material needs to be Modified to play back at 24 fps so it's in slow motion.

Right click the 60 fps clips in the bin and select Modify>Interpret Footage... and set the frame rate to match the other footage.

Report · Dec 30, 2016

Hi Jim,

Thank you for your reply.

The 60fps footage is already in slow motion. It's as it should be. The video file is literally ready to go without any modification needed to make it look "right".

I assumed, perhaps incorrectly, that Premiere would read its frame rate and simply adopt whatever settings it had.

As I said above, if I create a new project and drag on a 60fps video on to the timeline, it plays as it should. But within my project, which has a mix of 60fps video and 25fps video it is causing the 60fps footage to look ever-so-slightly jerky (I can only compare the way it plays the 60fps footage as if the computer is processing a task and it's slowing down the video, but this is not the case).

There is something that I've missed somewhere....a setting or an option. Either that or Adobe Premiere Pro is actually quite useless and can't handle different frame rates on the same timeline (which I'm beginning to think is the case!!!)

Report · Dec 30, 2016

if I create a new project and drag on a 60fps video on to the timeline, it plays as it should.

Define "as it should". Does that mean at 24 fps in slow motion, or at 60 fps in real time?

One thing to note is that you should not mix ATSC and PAL. The math just doesn't work out. So are the other clips shot at 24 fps (ATSC) or 25 fps (PAL)?

Report · Dec 30, 2016

In your first post, you said you were working on a 24 fps sequence, in your last post you said 25 fps. Which is it?

Please post a screen shot of your sequence settings.

alistairc23206244 wrote:
The 60fps footage is already in slow motion. It's as it should be.

I am not clear what this means. Did you shoot at a higher frame rate, that the camera then outputs as a 60fps slow motion clip? What camera shot this footage?

If you are dropping a 60 fps clip into a 24 fps timeline, Premiere either needs to slow the 60 fps source clip down to 24 fps (slow the motion of the clip) which will play back all of the original 60 fps frames - OR drop (not display) frames so that only 24 of the 60 original frames are shown per second. If you choose the latter, the missing frames may make the clip appear less smooth when compared to the same clip displaying all 60 fps.

MtD

Report · Dec 30, 2016

The frame rate is actually 25fps. (apologies, I was only using 24fps as a standard example initially)

So, to give this project a proper explanation...

I am mixing timelapse footage created from LRTimelapse with video footage edited in DaVinci Resolve (more on that below)

The final videos from LRTimelapse are MP4 files at 25fps. All I need do is drop them in to my project and sort out transitions, etc (they do not need any frame rate tweaking).

The other lot of clips (the 60fps clips) were edited in DaVinci Resolve, and they are .MOV files. They too are "ready to go" and do not need any frame rate tweaking). They look slow-mo and need to stay that way.

So because these clips are done, all I want to do is put them on a timeline and transition them with dissolves and text.

DaVinci Resolve is technically a colour grading software and produces final video clips for use in any editing software you so desire (in my case, Premiere). The same with LRTimelapse: It's timelapse software that outputs a final video file for you to use wherever you so wish).

So my intention with Premiere Pro is to combine both sets of videos in my Premiere timeline to produce my little project.

Report · Dec 30, 2016

When you set the frame rate of the sequence, that becomes the frame rate of your edited work.

Is your final output NTSC or PAL?

Did you intend to be working with a PAL frame rate (25 fps) and an NTSC frame rate (60 fps)?

What is going to be done with the final output of your sequence (web, blu ray, broadcast, etc.)?

There is no editing software that will allow you to have a sequence that in some sections is one frame rate, and a different frame rate in another. Is that what you are trying to do?

If you are not happy with the way the 60 fps files look on the 25 fps timeline, then try the opposite - make a sequence at 60 fps an drop the 25 fps footage on to it.

MtD

Report · Dec 30, 2016

You're mixing ATSC and PAL here. That could very easily be the source of your difficulty.

You can mix 24, 30 & 60, or 25 and 50. You can't mix 25 and 60, so sort that out.

Report · Dec 30, 2016

Jim_Simon wrote:
You can mix 24, 30 & 60, or 25 and 50. You can't mix 25 and 60, so sort that out.

This is exactly right, the reason I suggested dropping the 25 fps on the 60 fps timeline was because the OP said the 25 fps footage was time lapse material, so the odd cadence that will result from doing so will (hopefully) be less noticeable.

MtD

Report · Dec 30, 2016

Thank you for all of your replies. As I am new to 60fps filming (I recently bought a Blackmagic Cinema Camera) then this is a huge learning curve. It's not something I have had any previous experience with.

I have done what Meg The Dog has suggested - I have made the sequence 60fps in "sequence settings" and have told Premiere to keep the 25fps footage as 25fps....it works a treat! The 25fps timelapse footage doesn't seem to be affected, but the 60fps footage plays as it should. For this particular project this will be a fine solution.

Question: Why is 25fps footage not compatible with 60fps footage?

Report · Dec 31, 2016

The math just doesn't work.

Report · Dec 31, 2016

When you are mixing frame rates - without either conforming or adjusting playback speed - you are either repeating frames (25fps to 60 fps) or deleting frames (60 fps to 25 fps). The cadence at which these repetitions or deletions occur is critical to the apparent smoothness of motion of the result. Smoother cadence is possible when the two frame rate ratios have a usable common denominator and not when they don't.

If you had been using a regular video clip instead of a time-lapse clip, this would likely have been more obvious.

MtD

Report · Dec 31, 2016

Very helpful, thank you very much!

So, if I've got this right: Do you think it's best, in future, if I export at 24fps when the intention is to use this 24fps footage along with 60fps footage?

Another option, which I would need to experiment with, is to export the final slow-motion video as 60fps normal speed in DaVinci Resolve (i.e, so that it looks fast-speed), and then reduce the frame rate in Premiere to 24 so that it would result in a slow-motion video on the 24fps timeline. Would that work?

Under what circumstances would anyone shoot 30fps? I'm not sure I really understand the 30fps thing.

Apologies for the questions and thank you for your patience. I have found it difficult (other than this forum) to find a coherent explanation for frame rates (plus, it's always better to chat to people who know their stuff!).

Report · Dec 31, 2016

alistairc23206244 wrote:
So, if I've got this right: Do you think it's best, in future, if I export at 24fps when the intention is to use this 24fps footage along with 60fps footage?

If you intend to use it on a on a 60 fps timeline, then export it from your time-lapse creation software at 60 fps. If you intend to use it on a 24 fps timeline, export it at 24 fps.

alistairc23206244 wrote:
Another option, which I would need to experiment with, is to export the final slow-motion video as 60fps normal speed in DaVinci Resolve (i.e, so that it looks fast-speed), and then reduce the frame rate in Premiere to 24 so that it would result in a slow-motion video on the 24fps timeline. Would that work?

If the original source footage is 60 fps, and you do your color correction in Resolve and export the file from Resolve at 60 fps, then import that file into Premiere to use on a 24 fps timeline - if you Modify the clip in Premiere so that the footage is interpreted to fun at 24 fps, then placing that clip on a 24 fps timeline it will result in smooth motion of the clip with the apparent speed of the action in the clip running at 40% the speed of real time.

alistairc23206244 wrote:
Under what circumstances would anyone shoot 30fps? I'm not sure I really understand the 30fps thing.

When you are delivering the project for broadcast or when you make the aesthetic choice to work at 30 fps.

MtD

Report · Jan 01, 2017

Thank you very much for your help.