diff --git a/bindings/py3devil1.py b/bindings/py3devil1.py
index 2e2aa92..ddccd4c 100755
--- a/bindings/py3devil1.py
+++ b/bindings/py3devil1.py
@@ -65,6 +65,10 @@ class Devil1TEX_FN(ctypes.Structure):
         ("printbatchdesc",  ctypes.CFUNCTYPE(
                                  None,
                                  ctypes.POINTER(TextureBatchDescriptor))),
+        ("getheader",     ctypes.CFUNCTYPE(
+                                 ctypes.c_bool, 
+                                 ctypes.POINTER(ctypes.POINTER(TexturePack)),
+                                 ctypes.c_char_p)),
         ("getbatchdesc",    ctypes.CFUNCTYPE(
                                  ctypes.c_bool,
                                  ctypes.POINTER(TextureBatchDescriptor),
@@ -179,6 +183,10 @@ class Devil1GEO_FN(ctypes.Structure):
         ("printcoordinate", ctypes.CFUNCTYPE(
                                      None,
                                      ctypes.POINTER(Coordinate))),
+        ("getheader",       ctypes.CFUNCTYPE(
+                                     None,
+                                     ctypes.POINTER(ctypes.POINTER(Header)),
+                                     ctypes.c_char_p)),
         ("getmeshheader",   ctypes.CFUNCTYPE(
                                      ctypes.c_bool,
                                      ctypes.POINTER(MeshHeader),
diff --git a/demo/extractmesh.c b/demo/extractmesh.c
index 71dbe23..d15dde7 100644
--- a/demo/extractmesh.c
+++ b/demo/extractmesh.c
@@ -59,10 +59,10 @@ void writemesh(const struct MeshHeader *mh,
 void extractmeshes(const char *filedata,
                    const char *filename,
                    unsigned int filesize) {
-    if (filedata == NULL || filesize <= 0) {
+    struct Header *h = NULL;
+    if (!(DEVIL1GEO.getheader(&h, filedata))|| filesize <= 0) {
         return;
     }
-    struct Header *h = (struct Header*)filedata;
     struct MeshHeader *mh = NULL;
     struct Mesh m;
     m.b = NULL;
diff --git a/demo/extracttexture.c b/demo/extracttexture.c
index f686ff7..8a187c3 100644
--- a/demo/extracttexture.c
+++ b/demo/extracttexture.c
@@ -8,10 +8,9 @@ void extracttextures(const char *filedata,
     struct Texture *t     = NULL;
     struct TextureBatchDescriptor *d = NULL;
     char * fmt            = NULL;
-    if (filedata == NULL || filesize == 0) {
+    if (!(DEVIL1TEX.getheader(&p, filedata)) || filesize == 0) {
         return;
     }
-    p = (struct TexturePack*)filedata;
     fmt = (char*)malloc(strlen(filename) + 3 + 4);
     unsigned int i;
     unsigned int j;
diff --git a/include/devil1geo.h b/include/devil1geo.h
index 7b6b3d2..7293041 100644
--- a/include/devil1geo.h
+++ b/include/devil1geo.h
@@ -85,6 +85,9 @@ typedef struct {
 // input: pointer to struct
     void (* const printcoordinate)(struct Coordinate*, unsigned int);
 
+// input: pointer to struct, file data
+    bool (* const getheader)      (struct Header**, const char*);
+
 // input: pointer of pointer to struct, order, file data
 // ** = 'pass by reference' of a pointer to struct
     bool (* const getmeshheader)  (struct MeshHeader**, 
@@ -96,11 +99,11 @@ typedef struct {
                                    unsigned int offset, 
                                    const char * const);
 
-// input: pointer to struct, order, file data
+// input: pointer to struct, order, file data, file size
     bool (* const getmesh)        (struct Mesh*, 
                                    unsigned int i, 
                                    const char*,
-                                   unsigned int filesize);
+                                   unsigned int);
 } fn_devil1geo;
 extern fn_devil1geo const DEVIL1GEO;
 
diff --git a/include/devil1tex.h b/include/devil1tex.h
index 9013b2b..f45be35 100644
--- a/include/devil1tex.h
+++ b/include/devil1tex.h
@@ -45,6 +45,9 @@ typedef struct {
 // input: pointer to struct
     void (* const printbatchdesc)(struct TextureBatchDescriptor*);
 
+// input: pointer to struct, file data
+    bool (* const getheader)     (struct TexturePack**, const char*);
+
 // input: pointer of pointer to struct, order, file data, file size
 // ** = 'pass by reference' of a pointer to struct
     bool (* const getbatchdesc)  (struct TextureBatchDescriptor**,
diff --git a/src/devil1geo.c b/src/devil1geo.c
index b329072..72357af 100644
--- a/src/devil1geo.c
+++ b/src/devil1geo.c
@@ -9,6 +9,7 @@ static void printmeshbatch(struct Batch*);
 
 static void printcoordinate(struct Coordinate*, unsigned int);
 
+static bool getgheader(struct Header**, const char*);
 
 static bool getmeshheader(struct MeshHeader**, unsigned int i, const char * const);
 
@@ -20,6 +21,7 @@ fn_devil1geo const DEVIL1GEO = {printgheader,
                                 printmeshheader,
                                 printmeshbatch,
                                 printcoordinate,
+                                getgheader,
                                 getmeshheader,
                                 getmeshbatch,
                                 getmesh};
@@ -74,14 +76,22 @@ static void printcoordinate(struct Coordinate *p, unsigned int count) {
     }
 }
 
+static bool getgheader(struct Header** h, const char* filedata) {
+    if (filedata == NULL) {
+        return false;
+    }
+    (*h) = (struct Header*)filedata;
+    return true;
+}
+
 static bool getmeshheader(struct MeshHeader **hs,
                    unsigned int i,
                    const char * const filedata) {
-    bool done = false;
-    if (hs == NULL || filedata == NULL) {
+    bool done        = false;
+    struct Header *h = NULL;
+    if (hs == NULL || !(getgheader(&h, filedata))) {
         return done;
     }
-    struct Header *h = (struct Header*)filedata;
     if (h -> numMesh < i) {
         return done;
     }
diff --git a/src/devil1tex.c b/src/devil1tex.c
index 5b4d8dd..f284cd8 100644
--- a/src/devil1tex.c
+++ b/src/devil1tex.c
@@ -8,8 +8,10 @@ static void printtph(struct TexturePack*);
 // Print Texture Batch Descriptor.
 static void printtbd(struct TextureBatchDescriptor*);
 
-// Get Texture Batch Descriptor.
+// Get Texture Pack Header
+static inline bool getpackheader(struct TexturePack**, const char*);
 
+// Get Texture Batch Descriptor.
 static bool gettexdescriptor(struct TextureBatchDescriptor**,
                       unsigned int,
                       const char *,
@@ -30,6 +32,7 @@ static bool unpacktexbatch(struct Texture*,
 
 fn_devil1tex const DEVIL1TEX = {printtph,
                                 printtbd,
+                                getpackheader,
                                 gettexdescriptor,
                                 gettexbatch,
                                 unpacktexbatch};
@@ -55,6 +58,14 @@ static void printtbd(struct TextureBatchDescriptor *bd) {
     }
 }
 
+inline static bool getpackheader(struct TexturePack** p, const char *filedata) {
+    if (filedata == NULL) {
+        return false;
+    }
+    (*p) = (struct TexturePack*)filedata;
+    return true;
+}
+
 static bool gettexdescriptor(struct TextureBatchDescriptor **descriptor,
                       unsigned int i,
                       const char *filedata,
@@ -75,10 +86,9 @@ static bool gettexbatch(struct TextureBatch **batch,
                  const char *filedata,
                  unsigned int filesize) {
     struct TexturePack *p = NULL;
-    if (filedata == NULL) {      // no data to get batch from.
+    if (!(getpackheader(&p, filedata))) {
         return false;
     }
-    p = (struct TexturePack*)filedata;
     if (i > p -> batchNumber) {  // no such batch in texture pack
         return false;
     }