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I recorded a "slow-motion" video with my Android phone and transferred it to my Windows computer. Now I have an MP4 file with a frame-rate of 240 fps. But when I play the video, it plays at normal speed. I want to create a video that I can upload to YouTube or Facebook that plays at 1/8 speed (30 fps).

I thought I could do that with the free Movie Maker that comes with Windows. But when I select 1/8 speed it comes out chunky. It looks like the software converted the video to 30 fps when it loaded, and is now playing back that 30 fps video at 1/8 speed. I'm guessing that Movie Maker can't do what I want.

How do I create a video so that when someone plays that video they see it in slow-motion?

  • If your Movie Maker software converted the 240fps video to 30fps when it loads it into a project, then you have exactly what you want. You then only need render it out at 30 fps and you have a slow-motion video. Of course the ffmpeg answer is also valid, but you may wish to make other adjustments, some of which are easy to do with ffmpeg (cropping, scaling, etc), others which benefit from having an interactive GUI (color correcting, etc). – Michael Tiemann Sep 5 '16 at 11:40
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    Sorry, Michael, I wasn't clear. When I say Movie Maker converted the video to 30 fps, I mean that it threw away the other 210 frames, resulting in a real-time 30 fps video. – David Dubois Sep 5 '16 at 12:26
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You can use ffmpeg, a free command-line tool, to do this:

ffmpeg -i input.mp4 -vf setpts=8*PTS -r 30 -crf 18 output.mp4

This slows down the video 8 times and output is 30 FPS.

  • I am using a gopro 5 video that in file properties indicates:<br/> duration 3 minutes<br/> framerate 120 fps<br/> <br/> I run the command <br/> 'ffmpeg -i input.mp4 -vf setpts=4*PTS -r 30 -crf 18 output.mp4'<br/> <br/> and the new file properties indicates:<br/> duration 12 minutes<br/> framerate 30 fps<br/> <br/> The problem was that I imported the new video in a Kdenlive new proyect, and skiping frame by frame with the arrow I see 3 continuous identical frame then change the image that repeats again and change every 3 or 4 frames. – AutoCiudad Apr 23 at 0:13
  • Upload the readout of ffprobe goprofile to pastebin or similar and share a link. – Gyan Apr 23 at 4:41

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