Software Utilities: Framecap
Framecap is a freeware video-frame-capture program for Windows.
It runs as a separate program, so your own code can be in any language. Communication with framecap is via Windows Event objects and shared memory. You don't have to worry about that unless you want to. The download package includes a dll that you can use to capture and access individual video frames.
License and Download
Copyright © 2003-2004 by Robin Hewitt.
Framecap is available as freeware under the BSD license. This is a less restrictive license than GNU. It's also much shorter.
1. Read the license.
2. Download FrameCap.
3. Follow the set up and usage instructions.