Working with 25fps timeline and adding videos to timeline with mixed frame rates and dimensions

In the same lockdown 🙂

All very good advice from everyone. Here's my take.

On a broadcast production using multiple frame framerates we would convert any non-25fps material to 25fps.

On a non-broadcast job (if the final program is not too long) I'd leave all material 'as is' and drop everything into your 25fps timeline.

Most of the time 60 & 30 fps material will look OK at 25fps. The worst is dropping 24fps into a 25 sequence. That, to me, always looks the worst.

Preview render your finished edit before export and watch for any 'judder'. If you are working with 'talking head' footage you are unlikely to see much wrong. Anything with camera movement might look bad. On any problem shots, right click the clip in your sequence, select 'speed/duration' and then from the 'time interpolation' drop down menu choose 'optical flow'. Preview render again and see if it looks better.

Good luck.

I mix frames rates all the time using Premiere Pro with no issues. I think all NLEs will do that and have done it for over 10 years.  

Hey there. Premiere is pretty good at interpolating different framerates so you can definitely mix them. I would set your sequence to be the framerate of your primary media or to your required delivery specs, which it sounds like you've done. Other framerates added directly to the sequence will not be sped up or slowed down, only that they would have frames added (duplicated) or removed depending on the framerate of the clips compared to the sequence, for example:

If you add a 60fps clip to a 30 fps sequence it will simply remove every other frame from the 60 fps media. Inversely, if you add a 30fps clip to a 60 fps sequence it will duplicate every single frame. So your sequence would be playing at 60fps but the media would still look 30fps.

Now, just because the clips get interpolated doesn't necessarily mean they will all look great. There are certain conversions that can be choppier than others, like a 24fps clip in a 30fps sequence will have 1 frame duplicated every 6 frames, which can add a little bit of a jitter. In some of those cases you can try changing the Frame Interpolation to something else, like Optical Flow, to see if it looks any better (or just cope with it).

Edit: I wanted to add that working with phone media can be a challenge for different reasons than just mixing framerates. You may be getting media that's in an HEVC codec, which can be difficult to work with, and the media will also likely be Variable Framerate, which can cause a lot of issues (audio going out of sync, render errors, playback issues). To learn more about VFR you can read some of this, which includes some transcoding solutions: https://www.reddit.com/r/VideoEditing/wiki/faq/vfr

Ideally you will be able to advise the various people shooting this stuff to shoot in a specific framerate (though the VFR notes will still apply. Nothing you can do about that.) But also it's best to have the phones set to Compatibility mode and not High Efficiency, and where possible to turn off HDR settings. At least on the Apple side those things are just going to give you headaches.