120 fps MOV files only plays in SlowMotion. How to get it to normal speed?

[MrSLML]

Hi

I received video files from a Nikon DSLM camera. H264 in the MOV container. Filmed at 120 fps. The problem now is that the clips are played as slow motion in all the programs I have tried (QT Player, VLC, FCP, Davinci etc.). Even worse is that the first few seconds run normally and the video then slows down to speed up again at the last second. QT only recognizes the videos as such with 30 fps. In the camera itself, however, the clips are played back at normal speed.

How do I get the clips to run completely at normal speed? The plan for this project was to work in Davinci, but I could also switch to FCP if necessary.

Thanks for any help!

 

[lin2log]

QT only recognizes the videos as such with 30 fps

Then your clips clearly weren't exported in their original 120fps. Plain and simple. QT Player doesn't lie.

the first few seconds run normally and the video then slows down to speed up again at the last second

Let me guess… the clips went through an iPhone or maybe Photos? Well, then whoever exported them didn't know what they were doing since you have to export them unaltered. Otherwise, you'll get exactly what you're seeing! The speed ramps (which you can remove btw!) are baked in at a standard 30fps.

 

[sevoneone]

Then your clips clearly weren't exported in their original 120fps. Plain and simple. QT Player doesn't lie.

Not necessarily. Many mirrorless cameras that are not specifically a "cinema" camera will record 120fps, but encode the resulting video to playback at 25 or 30 fps. I'm not familiar with Nikon's, but I know the Canon R5, R7 and R8 do this. You have to jump up to the R5C, C70 or C80 to get 120fps encoded footage.

You are still recording 120fps. 1/4 speed video playing at 30fps is still 120 frames captured per second. The playback frame rate is essentially just metadata telling the player how fast to advance frames. All the frames are there. you just need to conform the clip in your editor. If you have the footage in a 120fps timeline in Final Cut, open the Retime menu and choose Automatic, that will make it so one frame of the clip is equal to one frame on the timeline playing in "realtime". In resolve, you'll manually have to enter the adjustment for the clip to play at 400% speed.

 

[arw]

While there are likely more elegant ways, the few times I need to achieve what you seek, I do the following:
The whole process is lossless (only remuxing in different containers) and therefore very fast.
- Open the video file in MKVToolNix , select the video stream, set "FPS" to "120fps" and click "Start multiplexing" (see screenshot).
This will create an mkv file which now has the correct speed information (120 fps).
If you want the file to be in an mp4 container (for compatibility reasons), proceed:
- Open the resulting mkv video file in Subler , then click File > Save > MPEG-4 movie > Save
This will create an mp4 file which still has correct speed information (120 fps).

I am not familiar with iMovie, Final Cut or Avidemux which can possibly do the same in one step.