[mythtv] Proof of concept: Chromakey OSD

[Andy Poling]

On Wed, 23 Mar 2005, Brad Templeton wrote:
> You note the ability to display OSD in the pillarboxes and letterboxes.
> That would be very cool, in fact it seems right to me to deliberately
> do this to avoid stomping on the actual video.   Of course, if the
> pillars or letterbox bars are in the actual video signal you would
> have to figure that out which is a whole other ballgame.

Actually, that's a pleasant side effect of the fact that the code only needs
to care about the size of the chromakey background window.  The video stream's
size, aspect ratio and composition are immaterial, which significantly
simplifies life.  No funky scaling and guessing about what size the video
stream is.  Just use the plain old-fashioned X window that's providing the
chromakey.  Aside from any xrandr activity, the OSD need not worry about
size changes.

Once I got to thinking about it and realized how many variables it removes
from the equation, it was quite an ah-hah.  :-)

-Andy