* Outputs ASS lines with basic coloring and font scaling for each
given region.
* Sets the default style to the resolution of the subtitle plane
(for example, 960x540 / 36pt font for profile A).
* Has options to:
* Disable ruby text (which is coded as regions which have
half-height text in libaribb24).
Enabled by default as without positioning ruby text only
confuses as it is usually coded in the beginning of the decoded
subtitle line.
* Set the working directory, in which libaribb24 will read
configuration as well as into which it may save broadcast extra
symbols as PNG.
Unset by default.
The unconventional library check can be explained by the library's
current master branch being licensed as LGPLv3, but at the time of
writing the latest official release is still licensed under GPLv3.
Thus, one either has to wait for the following release, or enable
GPLv3.
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk