[mythtv] Patch to autodetect 4:3 Zoom aspect ratio

[Petr Stehlik]

Mårten Bohlin wrote:
>>  I have a 16:9 display but most movies are broadcasted in 4:3 (with
>>  correct aspect ratio, I never seen a movie with incorrect aspect ratio)
>>  so they are pillarboxed. A good compromise for pillarbox on 16:9 display
>>  is "half zoom" AKA 14:9 zoom that maintains the aspect ratio and removes
>>  part of the black bars. The 14:9 zoom could be enabled automagically if
>>  the left&right side black bars were detected...
> 
> Do you always want to switch to "half zoom" when you have a 16:9
> screen? I usually want to look at content that was produced in 4:3
> with the pillarbox. But I use "half zoom" sometimes but I think I want
> to switch to that mode manually.

it's matter of personal preference. I got used to 14:9 zoom because I 
hate the wide black bars so I switch everything to 14:9 unless there are 
subtitles that could get below the bottom of screen.

In other words the automatic zoom for pillarbox would have to be 
configurable in myth...

>>  But sometimes 16:9 movie is broadcasted in 4:3 (still with correct
>>  aspect ratio) by adding top&bottom black bars (letterbox) so on 16:9
>>  display it is then windowboxed. The code for detecting black bars could
>>  see this and enable full zoom to get rid of the black bars entirely.
> 
> This is what my patch is doing today.

Great, then the only missing thing is to adapt it to 0.21 zoom modes :-)

Petr