[mythtv] automatic 14:9 or 4:3 zoom based on black bars detection?

[Petr Stehlik]

Hi,

I got a widescreen TV but most TV material here comes in 4:3 format.
Such is best viewed with a 14:9 Zoom (I have patched MythTV to offer the
14:9 Zoom) to limit the wide black bars at left and right side by such
partial zooming (14:9 zoom is right between no zoom and 4:3 zoom).

Some movies even come in 4:3 format but with black bars on top and
bottom - such material is best viewed in 4:3 Zoom mode on widescreen TV.

Now I'd like to automate the switching between the zoom modes. First, if
the source is in 4:3 format then I'd like to enable the 14:9 Zoom by
default. Could someone please suggest a place in the source code to
check for the input format and to enable/disable the zoom?

Then, I think it would be cool if it was possible to detect on-the-fly
if there are black bars on top&bottom and if there are then enable the
4:3 Zoom automagically. Is it possible (and cheap) to detect the black
bars? Is there a code for it yet? Any idea what to modify and where,
please?

Thanks

Petr