Multi-Point Keystone Video Player

A simple (free) “projection mapping” tool for distorting video during playback. Stretch your image to fit into corners, ceilings, or other complex shapes.

The simple “keystone” adjustment on video projectors can fix vertical alignment problems, but sometimes I project video in odd places that require horizontal keystoning, diagonal keystoning, or even multi-point distortion (especially for corner projection).

Multi-Point Keystone Video Player is a tool I made for these special situations. It combines a movie player and an “extreme keystoning” engine. QuickTime movies play in a continuous loop and you “pin” each corner to an arbitrary location via the mouse. You can add more than 2 “pins” in each axis (as shown in the screenshot) to project into corners or multi-faceted objects.

 

How it works:

1. Focus your projector on the surface you want to project onto.
2. Launch the software and open a QuickTime movie. (It should start playing in the preview window.)
3. Choose the number of keystone corners you want (default is 2 x 2). A green circle marks the currently selected corner.
4. Press “Esc” to enter full-screen mode.  Drag the corner until it aligns with your projection surface.
5. Press the left or right arrow keys “< >” to select other corners for editing. Align them all.
6. Press “m” to hide the mouse and the overlay graphics. You’re done!

• All settings are saved and restored automatically.
• There is an option to start up in full-screen mode (after a short delay), so you can launch the app via Applescript with no user interaction.

“Real” projection-mapping tools support multiple sources and complex geometry, but they can be hard to use. (see: mapamok, VPT, madmapper, Millumin, LPMT, etc) Multi-Point Keystone Video Player is designed for gallery installations where simple setup and unattended operation are paramount. It just plays a movie in a continuous loop. It doesn’t keystone your whole computer desktop. It doesn’t project multiple videos or accept input from other apps.

This software is adapted from Joshua Goldberg’s code found in this forum thread.

Open source software released under the GPL license (details in download).