Bitplanes in GPU framestore over PCI express using GPU direct

Is it possible to do the following. Assuming a standard PC with a GPUdirect enabled GPU card installed.

If I create a new PCI express card with a processor on board. Could I use this processor to read the GPU Framestore memory over the PCI express bus using GPUdirect and dump the contents of the GPU framestore into a piece of memory.

I would like to extract the bitplanes of a video frame produced by the GPU and then pull them out the framestore and put them someplace else.

Would the host computer processor be involved much or can the ‘card’ processor sort out the transfer using GPU direct.