Flash Video in Linux and Webcam

You also experienced problems when trying to use a webcam from a flash application in your Firefox browser?
It claimed about not being able to detect the cam, whereas VLC finds and uses it perfectly.

Well, there's a known compatibility limitation between the underlying video-for-linux (v4l) layer.
Modern Linux systems use version 2, whereas the Flash applets seem to be comfortable only with version 1.

There's a possibility to force Firefox to use the version 1 of v4l, by launching it this way:
LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so firefox &

Now the Flash applet should be able to detect and use your webcam.

More details can be found in this article I found.