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
(no i would not have tried to implement this had i known what mess it is)
fixes at least:
CAMACI3_Sony_C
Originally committed as revision 14687 to svn://svn.ffmpeg.org/ffmpeg/trunk
