diff --git a/MP4/Makefile b/MP4/Makefile
index 2691494a..b8ed4103 100644
--- a/MP4/Makefile
+++ b/MP4/Makefile
@@ -1,4 +1,4 @@
-SRC = box_avcC.cpp box.cpp box_dinf.cpp box_dref.cpp box_esds.cpp box_ftyp.cpp box_hdlr.cpp box_hmhd.cpp box_mdhd.cpp box_mdia.cpp box_minf.cpp box_moov.cpp box_mvhd.cpp box_nmhd.cpp box_smhd.cpp box_stbl.cpp box_stco.cpp box_stsc.cpp box_stsd.cpp box_stts.cpp box_tkhd.cpp box_trak.cpp box_url.cpp box_vmhd.cpp main.cpp interface.cpp
+SRC = box_avcC.cpp box.cpp box_dinf.cpp box_dref.cpp box_esds.cpp box_ftyp.cpp box_hdlr.cpp box_hmhd.cpp box_mdhd.cpp box_mdia.cpp box_minf.cpp box_moov.cpp box_mvhd.cpp box_nmhd.cpp box_smhd.cpp box_stbl.cpp box_stco.cpp box_stsc.cpp box_stsd.cpp box_stts.cpp box_tkhd.cpp box_trak.cpp box_url.cpp box_vmhd.cpp main.cpp interface.cpp box_mdat.cpp
 OBJ = $(SRC:.cpp=.o)
 OUT = Boxtest
 INCLUDES = 
diff --git a/MP4/box_includes.h b/MP4/box_includes.h
index c83d6e0f..6b28de8c 100644
--- a/MP4/box_includes.h
+++ b/MP4/box_includes.h
@@ -21,3 +21,4 @@
 #include "box_trak.h"
 #include "box_url.h"
 #include "box_vmhd.h"
+#include "box_mdat.h"
diff --git a/MP4/box_mdat.cpp b/MP4/box_mdat.cpp
new file mode 100644
index 00000000..2a060568
--- /dev/null
+++ b/MP4/box_mdat.cpp
@@ -0,0 +1,17 @@
+#include "box_mdat.h"
+
+Box_mdat::Box_mdat( ) {
+  Container = new Box( 0x6D646174 );
+}
+
+Box_mdat::~Box_mdat() {
+  delete Container;
+}
+
+Box * Box_mdat::GetBox() {
+  return Container;
+}
+
+void Box_mdat::SetContent( uint8_t * NewData, uint32_t DataLength , uint32_t Offset ) {
+  Container->SetPayload(DataLength,NewData,Offset);
+}
diff --git a/MP4/box_mdat.h b/MP4/box_mdat.h
new file mode 100644
index 00000000..c44f605a
--- /dev/null
+++ b/MP4/box_mdat.h
@@ -0,0 +1,14 @@
+#include "box.h"
+#include <vector>
+#include <string>
+
+class Box_mdat {
+  public:
+    Box_mdat();
+    ~Box_mdat();
+    Box * GetBox();
+    void SetContent( uint8_t * NewData, uint32_t DataLength , uint32_t offset = 0 );
+  private:
+    Box * Container;
+};//Box_ftyp Class
+
diff --git a/MP4/interface.cpp b/MP4/interface.cpp
index f0a7f18c..1d8fdd58 100644
--- a/MP4/interface.cpp
+++ b/MP4/interface.cpp
@@ -4,8 +4,6 @@ Interface::Interface() {
   //Initializing local data
   Width = 0;
   Height = 0;
-  Duration = 0;
-  UnitsPerSecond = 0;
   //Creating the boxes
   ftyp = new Box_ftyp();
   moov = new Box_moov();
@@ -138,13 +136,20 @@ uint8_t * Interface::GetContents( ) {
 void Interface::UpdateContents( ) {
   if( !Width ) { fprintf(stderr,"WARNING: Width not set!\n"); }
   if( !Height ) { fprintf(stderr,"WARNING: Height not set!\n"); }
-  if( !Duration ) { fprintf(stderr,"WARNING: Duration not set!\n"); }
-  if( !UnitsPerSecond ) { fprintf(stderr,"WARNING: Timescale not set!\n"); }
-  if( stts.size() == 0 ) {
-    fprintf(stderr,"WARNING: No stts available!\n");
-  } else {
-    WriteSTTS();
-  }
+  if( !Duration.size() ) { fprintf(stderr,"WARNING: Duration not set!\n"); }
+  if( !UnitsPerSecond.size() ) { fprintf(stderr,"WARNING: Timescale not set!\n"); }
+  if( sttsvide.size() == 0 ) {
+    fprintf(stderr,"WARNING: No video stts available!\n");
+  } else { WriteSTTS( 1 ); }
+  if( sttssoun.size() == 0 ) {
+    fprintf(stderr,"WARNING: No sound stts available!\n");
+  } else { WriteSTTS( 2 ); }
+  if( stscvide.size() == 0 ) {
+    fprintf(stderr,"WARNING: No video stsc available!\n");
+  } else { WriteSTSC( 1 ); }
+  if( stscsoun.size() == 0 ) {
+    fprintf(stderr,"WARNING: No sound stsc available!\n");
+  } else { WriteSTSC( 2 ); }
   stsd_vide->WriteContent( );
   stco_vide->WriteContent( );
   stsc_vide->WriteContent( );
@@ -356,7 +361,7 @@ void Interface::SetOffsets( std::vector<uint32_t> NewOffsets, uint32_t Track ) {
     case 2:
       stco_soun->SetOffsets( NewOffsets );
       break;
-    default;
+    default:
       fprintf( stderr, "WARNING: Track %d does not exist, Offsets not written\n", Track );
       break;
   }