None of these symbols should be accessed directly, so declare them as
hidden.
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit d36beb3f69)
Based on code by DivX, Inc., heavily changed by Björn Axelsson [gecko acc.umu.se] and me.
Originally committed as revision 19222 to svn://svn.ffmpeg.org/ffmpeg/trunk
