The software has no way of setting the white and black levels of the projector, those can only be controlled by the video card and the projector itself. The software always displays a digitally black image, but how that converts to signal is outside the control of the software.
Your YouTube video is private, so I can’t look at it, but generally speaking, people have had trouble with the black levels being sent insufficiently black by certain video cards. Intel video seems to consistently work fine, but some nVidia and ATI cards especially have been problematic.
A workaround is to adjust the black level (a.k.a brightness) on the projector itself, but that also affects the white level (although you can try to compensate by turning the contrast up). This, however, will alter your exposure times such that others’ provided settings may no longer match what your system generates.
