SMHD en NMHD boxes finished

MP4/box_nmhd.cpp

@@ -0,0 +1,18 @@
+#include "box_nmhd.h"
+
+Box_nmhd::Box_nmhd( ) {
+  Container = new Box( 0x6E6D6864 );
+  SetReserved();
+}
+
+Box_nmhd::~Box_nmhd() {
+  delete Container;
+}
+
+Box * Box_nmhd::GetBox() {
+  return Container;
+}
+
+void Box_nmhd::SetReserved( ) {
+  Container->SetPayload((uint32_t)4,Box::uint32_to_uint8(0));
+}