How can I convert a video to 60fps without changing speed?

[fighuass]

I tried various things like FFmpeg, Premiere Pro, After Effects, and some sites, but they all sped up the video. MeGUI just doesn't work for me, and never has.

Basically, I want something like SVP. Bonus points if the program/method can output webm, but it's not necessary.

[smrpix]

I tried various things like FFmpeg, Premiere Pro, After Effects, and some sites, but they all sped up the video.

In Premiere or After Effects just set up a 60fps sequence. As long as you have interpreted your source material correctly it will play at the proper speed. From there you have a number of interpolation options from simple duplicated frames to sophisticated optical flow.

[fighuass]

just set up a 60fps sequence.

Hmm, how do I do this? In Premiere Pro I get this screen, and I'm not sure what to do.. http://puu.sh/noybO/8d0eaa2b11.png

From there you have a number of interpolation options from simple duplicated frames to sophisticated optical flow.

Also, I'm not sure where these options are supposed to be.

[smrpix]

Easy enough to find out:
https://helpx.adobe.com/premiere-pro/how-to/slow-motion.html
https://helpx.adobe.com/premiere-pro/using/duration-speed.html

[fighuass]

But that still changes the length/speed/duration of the video.

I'll try MeGUI again.

[smrpix]

But that still changes the length/speed/duration of the video.

I'll try MeGUI again.

Not quite. You are changing the length/speed of your video so the duration remains constant while playing at 60fps.

[Evil_Burrito]

If you know about SVP and MeGUI already, you should also know about avisynth. You can use the InterFrame (motion interpolation) script for extra smooth results or simply change the frame rate.

If you don't know what I am talking about, check out the InterFrame thread http://forum.doom9.org/showthread.php?p=1486831

[fighuass]

@Evil_Burrito: I just get this when opening the .avs: http://puu.sh/noEl2/4405b0e7af.png
And this when saving it: http://puu.sh/noEog/68c51494db.png

[Evil_Burrito]

I am not trying to be rude, but those errors have nothing to do with converting frame rates. You must learn how to use avisynth.

You probably didn't install all the required plugins (check the manual or comments in the script). Also, I recommend using the latest avisynth+.

[pandy]

Generally you search for Motion Frame Interpolation - this is very complex and non solvable problem with classical math approach (perhaps well trained neural network will provide good results).
https://en.wikipedia.org/wiki/Motion_interpolation