framecap - Capture camera input with Allegro, C++

Requires OpenCV, Allegro, and pthreads. Captures frames from a webcam. Usage:

CAPTURE *cap = create_capture();
BITMAP *bmp = capture_frame(cap);

Use capture_frame_nb to capture a frame in nonblocking mode (a NULL pointer is returned if no frame is available). Should work on Mac OS X, Linux, Windows; only tested on Windows.

(Source)