Comment 41 for bug 141372

Michael, you're right. Video overlays don't work with that setting.
I found another one with which the overlays do work: "4,1,1,1,0,1,2,1"
However, this setting has a different problem: When the X server
starts, the monitor goes into power save mode. To get picture, I have
to switch to a different virtual console, and then back again. But after
that everything works (including video overlay and GL).

Isn't there some documentation somewhere what the numbers mean?
Just guessing randomly doesn't seem like the best way to arrive at
a combination where everything works...