Problem : When qemu is launched from the command line the GUI of the virtual machine does not launch but only a message
VNC server started at 127.0.0.1:5869
appears on the terminal.
Solution : The problem most probably is because the sdl libraries have not been installed.
Hence install the same using the package manager of your respective distro.
For eg if you are running debian(ubuntu) based systems then run the following commands in the terminal
sudo apt-get install libsdl1.2-dev
Now try running the qemu and GUI should appear.