doxy header for udp protocol

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@12861 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/udp.c

@@ -18,6 +18,12 @@
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
+
+/**
+ * @file udp.c
+ * UDP protocol
+ */
+
 #include "avformat.h"
 #include <unistd.h>
 #include "network.h"