--sub-scale-by-window=no attempts to keep subs always at the same pixel
size.
The implementation is a bit all over the place, because it compensates
already done scaling by an inverse scale factor, but it will probably do
its job.
Fixes#1424. (The semantics and name of --sub-scale-with-window are
kept, and this adds a new option - the name is confusingly similar, but
it's actually analogue to --osd-scale-by-window.)
wm4
067bb9605c