diff --git a/configure.ac b/configure.ac
index 65e6d4f..3bff474 100644
--- a/configure.ac
+++ b/configure.ac
@@ -225,6 +225,33 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([ ], [ ])], [
 ], [
   AC_MSG_RESULT([no])
 ])
+CFLAGS="$save_CFLAGS"
+
+AC_DEFUN([AC_CHECK_FORTIFY_SOURCE], [
+  AC_MSG_CHECKING([for _FORTIFY_SOURCE value with -O2])
+  old_CFLAGS="$CFLAGS"
+  CFLAGS="$CFLAGS -O2"
+  AC_RUN_IFELSE(
+    [AC_LANG_SOURCE([[
+      #include <stdio.h>
+      #ifndef _FORTIFY_SOURCE
+      #error
+      #endif
+      int main() { printf("%d\n", _FORTIFY_SOURCE); return 0; }
+    ]])],
+    [
+      fortify_source_value=`./conftest$EXEEXT`
+    ],
+    [
+      AC_MSG_RESULT([no])
+      fortify_source_value=0
+    ]
+  )
+  CFLAGS="$old_CFLAGS"
+  AC_SUBST([fortify_source_value])
+])
+AC_CHECK_FORTIFY_SOURCE
+AM_CONDITIONAL([NO_FORTIFY_SOURCE], [test "x$fortify_source_value" = "x0"])
 
 dnl set the plugindir where plugins should be installed (for src/Makefile.am)
 if test "x${prefix}" = "x$HOME"; then
diff --git a/src/Makefile.am b/src/Makefile.am
index 9ee9e90..8dfd846 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -87,7 +87,7 @@ libgsticamerasrc_la_CPPFLAGS += -DCHROME_SLIM_CAMHAL
 endif
 
 # for hardening-check
-libgsticamerasrc_la_CPPFLAGS+= -fstack-protector -fPIE -fPIC -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security
+libgsticamerasrc_la_CPPFLAGS+= -fstack-protector -fPIE -fPIC -Wformat -Wformat-security
 
 libgsticamerasrc_la_LIBADD = $(GST_LIBS) \
     -lgstallocators-$(GST_API_VERSION) \
@@ -101,7 +101,13 @@ libgsticamerasrc_la_LIBADD = $(GST_LIBS) \
 
 libgsticamerasrc_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 # for hardening-check
-libgsticamerasrc_la_LDFLAGS += -fPIE -fPIC -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Wl,-z,relro -Wl,-z,now
+libgsticamerasrc_la_LDFLAGS += -fPIE -fPIC -Wformat -Wformat-security -Wl,-z,relro -Wl,-z,now
+
+# test default fortify level
+if NO_FORTIFY_SOURCE
+libgsticamerasrc_la_CPPFLAGS+= -D_FORTIFY_SOURCE=2
+libgsticamerasrc_la_LDFLAGS+= -D_FORTIFY_SOURCE=2
+endif
 
 # headers we need but don't want installed
 noinst_HEADERS = gstcamerasrc.h \
diff --git a/src/gstcameraformat.cpp b/src/gstcameraformat.cpp
index 374ee9c..891d9c5 100644
--- a/src/gstcameraformat.cpp
+++ b/src/gstcameraformat.cpp
@@ -385,15 +385,14 @@ GstCaps *gst_camerasrc_get_all_caps ()
   vector <cameraSrc_Main_Res_Range> main_res_range;
 
   static GstCaps *caps = NULL;
-  if (caps != NULL) {
-    return gst_caps_simplify(caps);
+  if (caps != NULL && GST_IS_CAPS(caps)) {
+    return caps;
   }
-  caps = gst_caps_new_empty();
 #if GST_VERSION_MINOR == 22 && GST_VERSION_MICRO == 6 || GST_VERSION_MINOR >= 23
   GstVaDisplay *display_drm = NULL;
   display_drm = gst_va_display_drm_new_from_path("/dev/dri/renderD128");
   if (NULL == display_drm) {
-    GST_ERROR("Couldn't create a VA DRM display");
+    g_printerr("Couldn't create a VA DRM display");
     return NULL;
   }
 #endif
@@ -406,8 +405,7 @@ GstCaps *gst_camerasrc_get_all_caps ()
     //get configuration of camera
     int ret = get_camera_info(i, info);
     if (ret != 0) {
-      GST_ERROR("failed to get camera info from libcamhal");
-      gst_caps_unref(caps);
+      g_printerr("failed to get camera info from libcamhal");
 #if GST_VERSION_MINOR == 22 && GST_VERSION_MICRO == 6 || GST_VERSION_MINOR >= 23
       if (display_drm) {
         gst_object_unref(display_drm);
@@ -420,8 +418,7 @@ GstCaps *gst_camerasrc_get_all_caps ()
 
     ret = register_format_and_resolution(configs, fmt_res, main_res_range);
     if (ret != 0) {
-        GST_ERROR("failed to get format info from libcamhal");
-        gst_caps_unref(caps);
+        g_printerr("failed to get format info from libcamhal");
 #if GST_VERSION_MINOR == 22 && GST_VERSION_MICRO == 6 || GST_VERSION_MINOR >= 23
         if (display_drm) {
           gst_object_unref(display_drm);
@@ -432,11 +429,13 @@ GstCaps *gst_camerasrc_get_all_caps ()
     }
   }
 
+  caps = gst_caps_new_empty();
 #if GST_VERSION_MINOR == 22 && GST_VERSION_MICRO == 6 || GST_VERSION_MINOR >= 23
   set_structure_to_caps(main_res_range, &caps, display_drm);
 #else
   set_structure_to_caps(main_res_range, &caps);
 #endif
+  caps = gst_caps_simplify(caps);
   main_res_range.clear();
 #if GST_VERSION_MINOR == 22 && GST_VERSION_MICRO == 6 || GST_VERSION_MINOR >= 23
   if (display_drm) {
@@ -445,5 +444,5 @@ GstCaps *gst_camerasrc_get_all_caps ()
   }
 #endif
 
-  return gst_caps_simplify(caps);
+  return caps;
 }
diff --git a/src/gstcameraformat.h b/src/gstcameraformat.h
index ed55bf3..949af15 100644
--- a/src/gstcameraformat.h
+++ b/src/gstcameraformat.h
@@ -44,9 +44,6 @@
 #ifndef __GST_CAMERAFORMAT_H__
 #define __GST_CAMERAFORMAT_H__
 
-GST_DEBUG_CATEGORY_EXTERN(gst_camerasrc_debug);
-#define GST_CAT_DEFAULT gst_camerasrc_debug
-
 GstCaps *gst_camerasrc_get_all_caps ();
 
 #endif /* __GST_CAMERAFORMAT_H__ */
diff --git a/src/gstcamerasrc.cpp b/src/gstcamerasrc.cpp
index e068bcd..e46379b 100644
--- a/src/gstcamerasrc.cpp
+++ b/src/gstcamerasrc.cpp
@@ -177,7 +177,7 @@ G_DEFINE_TYPE_WITH_CODE (Gstcamerasrc, gst_camerasrc, GST_TYPE_CAM_PUSH_SRC,
 G_DEFINE_TYPE_WITH_CODE (Gstcamerasrc, gst_camerasrc, GST_TYPE_CAM_PUSH_SRC,
         G_IMPLEMENT_INTERFACE(GST_TYPE_CAMERASRC_3A_IF, gst_camerasrc_3a_interface_init);
         G_IMPLEMENT_INTERFACE(GST_TYPE_CAMERASRC_ISP_IF, gst_camerasrc_isp_interface_init);
-        G_IMPLEMENT_INTERFACE(GST_TYPE_CAMERASRC_DEWARPING_IF, gst_camerasrc_dewarping_interface_init) );
+        G_IMPLEMENT_INTERFACE(GST_TYPE_CAMERASRC_DEWARPING_IF, gst_camerasrc_dewarping_interface_init));
 #endif
 
 static void gst_camerasrc_set_property (GObject * object, guint prop_id,
@@ -922,13 +922,13 @@ static GstStaticPadTemplate video_pad_template = GST_STATIC_PAD_TEMPLATE(
   GST_CAM_BASE_VIDEO_PAD_NAMES,
   GST_PAD_SRC,
   GST_PAD_REQUEST,
-  gst_camerasrc_get_all_caps());
+  {gst_camerasrc_get_all_caps()});
 
 static GstStaticPadTemplate still_pad_template = GST_STATIC_PAD_TEMPLATE(
   GST_CAM_BASE_STILL_PAD_NAMES,
   GST_PAD_SRC,
   GST_PAD_REQUEST,
-  gst_camerasrc_get_all_caps());
+  {gst_camerasrc_get_all_caps()});
 
 static void
 gst_camerasrc_class_init (GstcamerasrcClass * klass)
@@ -953,6 +953,8 @@ gst_camerasrc_class_init (GstcamerasrcClass * klass)
   gstelement_class->request_new_pad = GST_DEBUG_FUNCPTR(gst_camerasrc_request_new_pad);
   gstelement_class->release_pad = GST_DEBUG_FUNCPTR(gst_camerasrc_release_pad);
 
+  GST_DEBUG_CATEGORY_INIT(gst_camerasrc_debug, "icamerasrc", 0, "camerasrc source element");
+
   g_object_class_install_property(gobject_class,PROP_BUFFERCOUNT,
       g_param_spec_int("buffer-count","buffer count","The number of buffer to allocate when do the streaming",
         MIN_PROP_BUFFERCOUNT,MAX_PROP_BUFFERCOUNT,DEFAULT_PROP_BUFFERCOUNT,
@@ -1227,8 +1229,6 @@ gst_camerasrc_class_init (GstcamerasrcClass * klass)
   basesrc_class->negotiate = GST_DEBUG_FUNCPTR(gst_camerasrc_negotiate);
   basesrc_class->decide_allocation = GST_DEBUG_FUNCPTR(gst_camerasrc_decide_allocation);
   pushsrc_class->fill = GST_DEBUG_FUNCPTR(gst_camerasrc_fill);
-
-  GST_DEBUG_CATEGORY_INIT (gst_camerasrc_debug, "icamerasrc", 0, "camerasrc source element");
 }
 
 static void
diff --git a/src/gstcamerasrcbufferpool.cpp b/src/gstcamerasrcbufferpool.cpp
index 8fa999a..2d253c9 100644
--- a/src/gstcamerasrcbufferpool.cpp
+++ b/src/gstcamerasrcbufferpool.cpp
@@ -89,6 +89,19 @@ gst_camerasrc_meta_api_get_type (void)
   return type;
 }
 
+static gboolean
+gst_camerasrc_meta_init (GstMeta * meta, gpointer params, GstBuffer * buffer)
+{
+  GstCamerasrcMeta *emeta = (GstCamerasrcMeta *) meta;
+
+  emeta->index = 0;
+  emeta->mem = NULL;
+  emeta->buffer = NULL;
+
+  return TRUE;
+}
+
+
 const GstMetaInfo *
 gst_camerasrc_meta_get_info (void)
 {
@@ -98,7 +111,7 @@ gst_camerasrc_meta_get_info (void)
   if (g_once_init_enter (&meta_info)) {
     const GstMetaInfo *meta =
         gst_meta_register (gst_camerasrc_meta_api_get_type (), "GstCamerasrcMeta",
-        sizeof (GstCamerasrcMeta), (GstMetaInitFunction) NULL,
+        sizeof (GstCamerasrcMeta), gst_camerasrc_meta_init,
         (GstMetaFreeFunction) NULL, (GstMetaTransformFunction) NULL);
     g_once_init_leave (&meta_info, meta);
   }
diff --git a/src/interfaces/Makefile.am b/src/interfaces/Makefile.am
index afdcc25..4d9d77e 100644
--- a/src/interfaces/Makefile.am
+++ b/src/interfaces/Makefile.am
@@ -59,12 +59,18 @@ libgsticamerainterface_@GST_API_VERSION@_la_CPPFLAGS += -DCHROME_SLIM_CAMHAL
 endif
 
 # for hardening-check
-libgsticamerainterface_@GST_API_VERSION@_la_CPPFLAGS += -fstack-protector-all -fPIE -fPIC -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security
+libgsticamerainterface_@GST_API_VERSION@_la_CPPFLAGS += -fstack-protector-all -fPIE -fPIC -Wformat -Wformat-security
 
 libgsticamerainterface_@GST_API_VERSION@_la_LIBADD = $(GST_LIBS) $(CAMHAL_LIBS)
 
 # for hardening-check
-libgsticamerainterface_@GST_API_VERSION@_la_LDFLAGS = -fPIE -fPIC -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Wl,-z,relro -Wl,-z,now -version-info $(LT_VERSION_INFO)
+libgsticamerainterface_@GST_API_VERSION@_la_LDFLAGS = -fPIE -fPIC -Wformat -Wformat-security -Wl,-z,relro -Wl,-z,now -version-info $(LT_VERSION_INFO)
+
+# test default fortify level
+if NO_FORTIFY_SOURCE
+libgsticamerainterface_@GST_API_VERSION@_la_CPPFLAGS+= -D_FORTIFY_SOURCE=2
+libgsticamerainterface_@GST_API_VERSION@_la_LDFLAGS+= -D_FORTIFY_SOURCE=2
+endif
 
 libgsticamerainterfaceincludedir = $(includedir)/gstreamer-@GST_API_VERSION@/gst/icamera