Chroma Key Live
Free Real-time HD Green-Screen Software
Chroma Key Live “keys out” selected areas of your camera feed, allowing your background image to show through. It supports HD resolutions and offers full GPU acceleration.
I didn’t need the advanced features of expensive chromakey (“greenscreen”) software like Veescope, Wirecast, BoinxTV, VirtualEyez, or Visual Communicator so I made my own solution. Chroma Key Live gives you control over key tolerance and edge fade, and offers features like full-screen mode, image-flip (so your actors don’t see themselves backwards), and a useful “transport” so you can control the playback of your background videos. SD and HD formats are supported and there are keyboard shortcuts for all important functions.
In the days of analog video…
the camera’s live signal was routed through a keyer in the control room and delivered back to an on-set monitor. This way, the production team could see exactly how the actor looked when composited over the background image. Of course, you needed an expensive studio or at least a video mixer.
Then came the DV era…
and editing software brought chroma keying to the masses… sort of. How do you shoot a complex green-screen scene when all you see is an actor against a big green wall?
Now it’s simple again…
Run the firewire output from your camera into a laptop running Chroma Key Live. Click on your background and it will disappear, revealing the movie or still image of your choice. Switch to full-screen and call “action!”
OK. But what about HD?
This is where things get weird. Perhaps you’ve noticed that newer HD video cameras record onto memory cards instead of tapes. Very few cameras still have Firewire ports, and there is no standardized interface for live “streaming” of video frames over USB. Most cameras have HDMI outputs, but laptops can’t capture the signal without expensive hardware. So the future of Chroma Key Live is uncertain. Panasonic DVCProHD cameras stream via firewire in certain modes, or you can use an HDMI capture card in a full-size computer. See the Chroma Key Live Guide for complete info.
Download Current Version
2011-11-08 (Mac Intel/PPC)
Nov 8, 2011, 19MB with source “patches” for MAX/MSP/Jitter 5. (Tested with Mac OS 10.5 Leopard.)
Please read the Chroma Key Live Guide for instructions and a detailed Changelog.
For Snow Leopard compatibility you must install Quicktime 7.
There is no Windows version. If you are a MAX/MSP user and want to compile your own, my download link points to a Mac disk image which you can open with HFSExplorer on Windows. Inside you will find the cross-platform source patches.
Caveats
- It cannot record. It strictly displays on the computer screen for on-set preview. You can do much better chroma keys in post-production software!
- It cannot chroma-key your camera signal while sending it to other applications.
Try CamTwist or VirtualEyez for that.
Changes in this version:
- The live camera image can now be scaled and positioned. (Example 1: You compose your shot so an actor fills the frame. In Chroma Key Live you shrink the actor and position him to fit into a small doorway in your background elements. Your camera footage is full-frame so you can change your mind in post. Example 2: You are shooting with a Canon 5DmkII, feeding the HDMI signal into Chroma Key Live via a capture card. The 5D image doesn’t fill the entire frame but now you can scale it up using Chroma Key Live, to match 1080 background elements.)
Old Versions:
(See the Chroma Key Live Guide for changelog.)
2010-12-03 (Mac Intel/PPC) Dec 03, 2010, 19MB with source “patches” for MAX/MSP/Jitter 5. (Tested with Mac OS 10.5 Leopard.)
2009-11-03 (Mac Intel/PPC) Nov 03, 2009, 16MB with source “patches” for MAX/MSP/Jitter 5. (Tested with Mac OS 10.5 Leopard.)
2008-12-16 (Mac Intel/PPC) Dec 16, 2008, 16MB with source “patches” for MAX/MSP/Jitter 5. (Tested with Mac OS 10.5 Leopard.) This version used the CPU instead of the GPU, so it will work on an old PPC Mac Mini with Intel GMA graphics.