What is the best way to speed up GH4 footage shot in a variable frame rate (36fps) to real time 24fps?

[Dan Powers]

After Effects is your best bet to restore it to it’s proper speed. The good news is that you have more frames than you need. The opposite is much worse.
1 in 3 frames is going to be kicked out so I would play with the various frame interpolation modes. Blend, Mix, Pixel motion etc.
Play with nesting the clip and time stretching, then adjust your quality.
If you have a short clip that I could download I could test some settings for you.

[Alicia Agramonte]

Would really appreciate that. Here’s a link to a small file! https://www.dropbox.com/s/5ng9f9qhnhdqg5v/P1080822.MOV?dl=0

I will say I did try speed duration to 150% (1.5x) and after rendering it doesn’t look bad but I want to make sure that doesn’t kill me later when exporting. Would hate for this to come out choppy.

[Andreas Kiel]

If you do 1.5 time scale you will get a slomo.
The other way would be merging frames like said above. Merge 2 with 3, 5 with 6 etc.
I personally wouldn’t drop frames – like every third one.

– Andreas

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[Dan Powers]

Your clip has subjects mostly walking toward camera, so there isnt much information lost in the kicked out frames. If you have action crossing fully across frame, you will notice it more.

I tried two different processes, both in After Effects, but same can be done in Premiere.
One, 23.976 Timeline, footage interpreted to 36fps.
Other was 23.976 timeline with footage interpreted to 23.976 and time stretched by 66.734% and tried the different interpolation methods. Again on this clip, there wasnt much difference.
But 1.5X (75% time stretch equivalent) speed is a no go. That is not an accurate speed correction. You are going to have to do a 66.734

Good luck.

[Alicia Agramonte]

Thank you!!! I ended up doing 67% over the weekend and after a bit of a trial and error, the sound just started linking with all videos easily (though manually. Shooting in VFR is a nightmare if you have to match up external sound). Not quite sure what the difference is between VFR and just shooting up to a different frame rate but I guess thats a question for another thread. Thanks guys!