added doc

diff --git a/src/pdf2swf.c b/src/pdf2swf.c
index 6e1c096..4526019 100644 (file)
--- a/src/pdf2swf.c
+++ b/src/pdf2swf.c
@@ -414,6 +414,7 @@ void args_callback_usage(char*name)
           "                           graphic errors)\n");
     printf("-s filloverlap             Make intersecting shapes overlap, instead of canceling each\n"
           "                           other out. (Needed for some Powerpoint PDFs)\n");
+    printf("-s transparent             Make the SWF transparent\n");
     //deliberately undocumented (for now)
     //printf("-2                         Put 2 pages into each frame.\n");
     //printf("-4                         Put 4 pages into each frame.\n");