[MPlayer-dev-eng] preserving aspect with crop&expand filters

[D Richard Felker III]

Is there any simple way to make the crop and expand filters adjust the
display width and height that pass through them, so as to preserve
aspect? This only matters on vo's with hardware scaling or -zoom I
guess, but it's a bit of a pain having to specify -x and -y to fix
broken aspect after expanding (to make room for subs) or cropping (to
eliminate letterbox space, for example).

Rich