David Haberthür edited this page Aug 23, 2017 · 4 revisions
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slowmoVideo is an OpenSource program that creates slow-motion videos from your footage.

But it does not simply make your videos play at 0.01× speed. You can smoothly slow down and speed up your footage, optionally with motion blur.

How does slow motion work? slowmoVideo tries to find out where pixels move in the video (this information is called Optical Flow), and then uses this information to calculate the additional frames between the ones recorded by your camera.


  • Videos in any format supported by ffmpeg can be loaded. Image sequences can also be loaded, so, if you did a timelapse with too few frames, slowmoVideo may help as well.
  • slowmoVideo does not work with a constant slowdown factor but with curves that allow arbitrary time accelereation/deceleration/reversal.
  • Motion blur can be added, as much as you want.

The most recent changes to slowmoVideo can be read in the changelog.


These parts are used by slowmoVideo:

  • Qt4/Qt5 as C++ programming framework
  • GPU-KLT+FLOW and OpenCV for calculating the optical flow
  • ffmpeg for reading and writing video files


slowmoVideo was originally written by Granjow as bachelor thesis at ETH Zürich. The thesis can be read here (PDF, 2 MB).