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

Mårten Bohlin mabo at mochc.net
Fri Feb 22 14:24:15 UTC 2008

On Fri, Feb 22, 2008 at 2:53 PM, Petr Stehlik <pstehlik at sophics.cz> wrote:
> Mårten Bohlin wrote:
>  >>  This is very cool. Though the zoom modes changed a bit in 0.21 but that
>  >>  will make it even easier probably. Great would be to extend this to
>  >>  detect also black bars on left and right sides for automatic half and
>  >>  full zoom on 16:9 displays :-)
>  >
> > I am not sure what you mean. My code solves the problem for people
>  > that have 16:9 displays and watch movies that has the 16:9 aspect
>  > ratio, but are broadcasted in 4:3. So I guess this is what you want to
>  > do?
>  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.

>  Actually it should be detected by checking the source aspect ratio, not
>  by checking the black bars, sorry (as the black bars are not really
>  there in the source material). I tried to add such code there but for
>  some reason it works for live TV only, not for recordings..

My patch works both for recordings and live TV.

>  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.

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