linuxqtembeddedvnc

Mouse cursor in VNC jumps

Started an X11VNC server on my embedded linux device and connect with a VNC client (TigerVNC or Guacamole). The VNC server streams directly the framebuffer to port 5901. The cursor jumps badly when moved over the GUI (see video).

enter image description here

x11vnc -rfbport 5901 -no6 -rawfb /dev/fb0 -scale 640x480x16x1280 -verbose -cursor none -nodragging -pipeinput UINPUT:direct_abs=/dev/uinput

tried lots of additional parameters without success: -pointer_mode n -extra_fbur n -visual TrueColor:32 -noshm

Solution

  • I suspect the problem was in the default acceleration.

    see documentation

    Note: the default acceleration is 2.0 since it seems both X and qt-embedded often (but not always) use this value.

    so the edited x11vnc command includes accel=1.0:

    x11vnc -rfbport 5901 -no6 -rawfb /dev/fb0 -verbose -cursor none -nodragging -pipeinput UINPUT:direct_abs=/dev/uinput,accel=1.0 -forever