Add symbol versioning for shared libraries

Based on patch by Reinhard Tartler <siretart tauware de>

Originally committed as revision 21236 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 3 insertions, 0 deletions

diff --git a/libavformat/libavformat.v b/libavformat/libavformat.v
new file mode 100644
index 0000000000..da2311eb36
--- /dev/null
+++ b/libavformat/libavformat.v
@@ -0,0 +1,3 @@
+LIBAVFORMAT_$MAJOR {
+        global: *;
+};