fixed multicast connect

Originally committed as revision 1221 to svn://svn.ffmpeg.org/ffmpeg/trunk

libav/udp.c

@@ -141,13 +141,13 @@ static int udp_open(URLContext *h, const char *uri, int flags)
     if (udp_fd < 0)
         goto fail;
 
+    my_addr.sin_family = AF_INET;
+    my_addr.sin_addr.s_addr = htonl (INADDR_ANY);
     if (s->is_multicast && !(h->flags & URL_WRONLY)) {
-        /* special case: the bind must be done on the multicast address */
-        my_addr = s->dest_addr;
+        /* special case: the bind must be done on the multicast address port */
+        my_addr.sin_port = s->dest_addr.sin_port;
     } else {
-        my_addr.sin_family = AF_INET;
         my_addr.sin_port = htons(s->local_port);
-        my_addr.sin_addr.s_addr = htonl (INADDR_ANY);
     }
 
     /* the bind is needed to give a port to the socket now */