[mythtv] Proof of concept: Chromakey OSD

Brad Templeton brad+mydev at templetons.com
Thu Mar 24 19:50:17 UTC 2005


On Thu, Mar 24, 2005 at 08:45:26AM -0500, Andy Poling wrote:
> 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.  :-)

And while I find PiP to be generally a useless feature on a PVR, for those
who are keen on it, doing it with a window in the chromakey makes great
sense, if that's not in fact how it is already done.


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