SlowmoVideo is a free open source program to create slow motion video from your video footage. It was released for Linux last year and was very well received but now there is a Windows version too
The developer wrote slowmoVideo as his bachelor thesis (hope he got an A!) and it doesn’t just make videos play at 0.1x speed – you can smoothly slow down and speed up your footage, optionally with motion blur or render video clips backwards too.
How Does SlowmoVideo Work? According to the developer it “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”.
I don’t claim to understand all the technical details – if you want the full explanation his original thesis is available as a PDF file from the program website here. The main features include:
- 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 – this allows arbitrary time acceleration or deceleration or reversal of the video footage.
- Motion blur can be added, as much as you want.
Further info and guides are available from the website here but I found that they assumed a bit much. A good Youtube tutorial is available here – note this is for the Linux version but the program usage and techniques are very similar for the Windows version – launching the actual program starts about 9.00 minutes in.
Perhaps the best way of showcasing slowmoVideo is to look at an example video of its use:
There are some more video examples here.
Download slowmoVideo for Windows here – follow the tips carefully and note that you do need ffmpeg in the same directory as the main slowmoUI program.
If you need to download ffmpeg it’s in 7z format – extract it with an archive manager e.g. 7-zip or Peazip.
slowmoVideo enjoys something of a cult following on Linux so the release of a new Windows version is a long awaited bonus.
The program installation process and documentation are a little rough around the edges but more experienced Windows users and those used to video rendering should pick it up fairly quickly by following the guides.
Quite how good the end result is depends on how you use it – this is not a program to just automatically slow down video footage by a set amount throughout (although you can easily make it do that).
You get to choose the levels you wish to speed footage (up, down or reverse) and that level of granularity is the whole point – some experimentation may be required to get the best results and, as with any video rendering, a quick PC will be of benefit.
In my own quick tests I achieved very reasonable results for a rank amateur – enough to give a glimpse of just what slowmoVideo is capable of in the right hands.