[mythtv-users] Calculating aspect ratios for DVDs

[Yan Seiner]

This is slightly OT, but I'm hoping someone can enlighten me.  I'm trying
to work out a script that automatically detects the aspect ratio of a
cropped DVD.

It seems that DVDs report either 1.33:1 aspect or 1.78:1 aspect.  If the
movie is 2.33:1, black bars are added top and bottom.  (leaving aside the
odd-ball ones for the moment.)

So to get the proper aspect, one would have to:

Take the DVD size, either 720x480 or 720x576, and figure out the crop box.

Take the reported DVD aspect ratio, divide by 1.33, multiply the width of
the crop box and divide the result by the height of the crop box.

This seems weirdly byzantine and possibly inaccurate.  Is there some
simple way to use mplayer, lsdvd, or dvdscan to get this information?

--Yan

-- 
If you have eight hours to chop down a tree
spend six sharpening your axe.
--Abraham Lincoln