—> No, this command can be used normally. Please try the following command again:
/ # export XDG_RUNTIME_DIR=/run/user/root
/ # gst-launch-1.0 -e qtiqmmfsrc camera=0 name=qmmf ! video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! waylandsink x=0 y=0 width=640 height=480
