Canon EOS-1D X Instruction Manual page 31

Select [Transfer with SET].
4
Select [Enable].
Select the image.
5
Press the <x> button on the
camera.
Select the image to transfer, and then
press <0> to transfer the image.
Movies cannot be transferred with
this function. If you select a movie
and press <0>, the movie
playback panel will be displayed.
Transferring Images Individually
31