Direct rendering

I’m a newbie in OpenGL and I’m asking to me if it is possible to display an image coming from a frame grabber directly to the video card. Without use local memory…
If it’s possible, how to do that?
I suppose I must send ONLY a client DC (device context) to OpenGL.
I think this technicque is call “Direct rendering” but I’m not sur.
Thanks in advance for your help.