Before this commit, the OSD was drawn using libass, but the resulting
bitmaps were converted to the internal mplayer OSD format. We want to
get rid of the old OSD format, because it's monochrome, and can't even
be rendered directly using modern video output methods (like with
OpenGL/Direct3D/VDPAU).
Change it so that VOs can get the ASS images directly, without
additional conversions. (This also has the consequence that the OSD can
render colors now.) Currently, this is vo_gl3 only. The other VOs still
use the old method. Also, the old OSD format is still used for all VOs
with DVD subtitles (spudec).
Rewrite sub.c. Remove all the awkward flags and bounding boxes and
change detection things. It turns out that much of that isn't needed.
Move code related to converting subtitle images to img_convert.c. (It
has to be noted that all of these conversions were already done before
in some places, and that the new code actually makes less use of them.)
Teletext requires special OSD support. Because I can't even test
teletext, I can't restore support for it. Since teletext can be
considered ancient and obscure, and since it doesn't make sense to keep
the remaining teletext code without being able to use it, I'm removing
it.
The previous commit made libass the default OSD renderer. This commit
removes the disabled freetype renderer completely. The commits were
done separately to make rolling back easier, because using libass for
OSD rendering is a risky choice.
Also remove freetype/fontconfig/fribidi code. This is all done by
libass now.
If mplayer is compiled without libass, no OSD is displayed.
