The only time it was flashing in my case, was because I had injected two input messages (by accidentally pressing the inject button twice). Then two streams are started and the images are mixed displayed. But I assume that won't be your case ...
Just copied them somewhere from one or another tutorial. I haven't had time yet to look at the settings in more detail. So be my guest if you have some spare time, and please share your results here ...
I would advice not to push the images to the dashboard via the websocket channel, unless you wan't to run into problems. In the following link you can find some ways to do it.
