[mythtv] Automatic zoom to remove black borders for dvb

[Torbjörn Jansson]

> I use dvb in australia on a 4:3 tv, and the display usually
> has black borders at the top and the bottom of the screen,
> but sometimes also on the left and right, depending on
> whether the content is broadcast in widescreen or not. It
> would be nice to have a feature which automatically selects
> zoom mode to at least get rid of the left and right black borders.
> 

DScaler used to have a function where it could detect black border above and
below the picture and remove them.
It's been a long time since i used dscaler but if you plan on implementing
something like this, maybe it coud be of some help?

Anyway, haven't used dscaler for a long time and even longer since did some
coding on it.

> Am I right in assuming that implementing this feature would
> involve some image processing to decide whether a black
> border is present or not?

Probably yes.

> Or is there meta data in the
> broadcast signal which provides the necessary information?
> 

WSS or whatever it's called tells what aspect it is in, but i asume that WSS
is not accurate and/or not being transmitted otherwise there wouldn't be a
problem