All: Use new GObject type macros

Bump ABI version since I canont guarantee ABI compatibility

33 files changed, 632 insertions, 823 deletions

diff --git a/configure.ac b/configure.ac
index 7a61616..91c8a76 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,7 @@ AX_CHECK_ENABLE_DEBUG([yes])
 
 dnl library versioning
 dnl Increase when changing the API
-GUPNP_DLNA_CURRENT=3
+GUPNP_DLNA_CURRENT=4
 
 dnl Update when changing implementation of current API,
 dnl reset to 0 when changing CURRENT.  This is the revision of
diff --git a/libgupnp-dlna/gupnp-dlna-audio-information.c b/libgupnp-dlna/gupnp-dlna-audio-information.c
index 1e646fa..9b0426e 100644
--- a/libgupnp-dlna/gupnp-dlna-audio-information.c
+++ b/libgupnp-dlna/gupnp-dlna-audio-information.c
@@ -50,6 +50,8 @@
 struct _GUPnPDLNAAudioInformationPrivate {
         gpointer placeholder;
 };
+typedef struct _GUPnPDLNAAudioInformationPrivate
+        GUPnPDLNAAudioInformationPrivate;
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAAudioInformation,
                         gupnp_dlna_audio_information,
@@ -76,10 +78,6 @@ gupnp_dlna_audio_information_class_init
 static void
 gupnp_dlna_audio_information_init (GUPnPDLNAAudioInformation *info)
 {
-        GUPnPDLNAAudioInformationPrivate *priv =
-            gupnp_dlna_audio_information_get_instance_private (info);
-
-        info->priv = priv;
 }
 
 /**
@@ -93,13 +91,13 @@ gupnp_dlna_audio_information_get_bitrate (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_bitrate != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -118,13 +116,13 @@ gupnp_dlna_audio_information_get_channels (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_channels != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -143,13 +141,13 @@ gupnp_dlna_audio_information_get_depth (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_depth != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -168,13 +166,13 @@ gupnp_dlna_audio_information_get_layer (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_layer != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -193,13 +191,13 @@ gupnp_dlna_audio_information_get_level (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_level != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -219,13 +217,13 @@ gupnp_dlna_audio_information_get_mpeg_audio_version
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mpeg_audio_version != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -244,13 +242,13 @@ gupnp_dlna_audio_information_get_mpeg_version (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mpeg_version != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -269,13 +267,13 @@ gupnp_dlna_audio_information_get_profile (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_profile != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -294,13 +292,13 @@ gupnp_dlna_audio_information_get_rate (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_rate != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -319,13 +317,13 @@ gupnp_dlna_audio_information_get_stream_format (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_stream_format != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -344,13 +342,13 @@ gupnp_dlna_audio_information_get_wma_version (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_wma_version != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -369,13 +367,13 @@ gupnp_dlna_audio_information_get_mime (GUPnPDLNAAudioInformation *info)
 {
         GUPnPDLNAAudioInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_AUDIO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_AUDIO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mime != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
diff --git a/libgupnp-dlna/gupnp-dlna-audio-information.h b/libgupnp-dlna/gupnp-dlna-audio-information.h
index 7662249..624c33e 100644
--- a/libgupnp-dlna/gupnp-dlna-audio-information.h
+++ b/libgupnp-dlna/gupnp-dlna-audio-information.h
@@ -27,40 +27,24 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_AUDIO_INFORMATION \
-        (gupnp_dlna_audio_information_get_type())
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAAudioInformation,
+                          gupnp_dlna_audio_information,
+                          GUPNP_DLNA,
+                          AUDIO_INFORMATION,
+                          GObject)
 
-#define GUPNP_DLNA_AUDIO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_AUDIO_INFORMATION, \
-                                     GUPnPDLNAAudioInformation))
+#define GUPNP_TYPE_DLNA_AUDIO_INFORMATION                                      \
+        (gupnp_dlna_audio_information_get_type ())
 
-#define GUPNP_DLNA_AUDIO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_AUDIO_INFORMATION, \
-                                  GUPnPDLNAAudioInformationClass))
-
-#define GUPNP_IS_DLNA_AUDIO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_AUDIO_INFORMATION))
-
-#define GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_AUDIO_INFORMATION))
-
-#define GUPNP_DLNA_AUDIO_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_AUDIO_INFORMATION, \
-                                    GUPnPDLNAAudioInformationClass))
-
-typedef struct _GUPnPDLNAAudioInformationPrivate
-                GUPnPDLNAAudioInformationPrivate;
-
-typedef struct {
-        GObject parent;
-
-        GUPnPDLNAAudioInformationPrivate *priv;
-} GUPnPDLNAAudioInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_AUDIO_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_AUDIO_INFORMATION GUPNP_DLNA_IS_AUDIO_INFORMATION
+/**
+ * GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_AUDIO_INFORMATION_CLASS GUPNP_DLNA_IS_AUDIO_INFORMATION_CLASS
 
 /**
  * GUPnPDLNAAudioInformationClass:
@@ -91,7 +75,7 @@ typedef struct {
  * type.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAAudioInformationClass {
         GObjectClass parent_class;
 
         GUPnPDLNAIntValue
@@ -131,10 +115,7 @@ typedef struct {
         (* get_mime) (GUPnPDLNAAudioInformation *info);
 
         gpointer _reserved[12];
-} GUPnPDLNAAudioInformationClass;
-
-GType
-gupnp_dlna_audio_information_get_type (void);
+};
 
 GUPnPDLNAIntValue
 gupnp_dlna_audio_information_get_bitrate (GUPnPDLNAAudioInformation *info);
diff --git a/libgupnp-dlna/gupnp-dlna-container-information.c b/libgupnp-dlna/gupnp-dlna-container-information.c
index 26aaa85..742449e 100644
--- a/libgupnp-dlna/gupnp-dlna-container-information.c
+++ b/libgupnp-dlna/gupnp-dlna-container-information.c
@@ -51,6 +51,8 @@
 struct _GUPnPDLNAContainerInformationPrivate {
         gpointer placeholder;
 };
+typedef struct _GUPnPDLNAContainerInformationPrivate
+        GUPnPDLNAContainerInformationPrivate;
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAContainerInformation,
                                      gupnp_dlna_container_information,
@@ -71,10 +73,6 @@ gupnp_dlna_container_information_class_init
 static void
 gupnp_dlna_container_information_init (GUPnPDLNAContainerInformation *info)
 {
-        GUPnPDLNAContainerInformationPrivate *priv = 
-            gupnp_dlna_container_information_get_instance_private (info);
-
-        info->priv = priv;
 }
 
 /**
@@ -89,13 +87,13 @@ gupnp_dlna_container_information_get_mpeg_version
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mpeg_version != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -115,13 +113,13 @@ gupnp_dlna_container_information_get_packet_size
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_packet_size != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -141,13 +139,13 @@ gupnp_dlna_container_information_get_profile
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_profile != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -167,13 +165,13 @@ gupnp_dlna_container_information_is_system_stream
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_BOOL_VALUE_UNSET);
         g_return_val_if_fail (info_class->is_system_stream != NULL,
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
@@ -193,13 +191,13 @@ gupnp_dlna_container_information_get_variant
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_variant != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -218,13 +216,13 @@ gupnp_dlna_container_information_get_mime (GUPnPDLNAContainerInformation *info)
 {
         GUPnPDLNAContainerInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_CONTAINER_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_CONTAINER_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                        (GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS (info_class),
+                        (GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS (info_class),
                          GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mime != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
diff --git a/libgupnp-dlna/gupnp-dlna-container-information.h b/libgupnp-dlna/gupnp-dlna-container-information.h
index 156bfd9..8ada6f1 100644
--- a/libgupnp-dlna/gupnp-dlna-container-information.h
+++ b/libgupnp-dlna/gupnp-dlna-container-information.h
@@ -27,40 +27,24 @@
 
 G_BEGIN_DECLS
 
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAContainerInformation,
+                          gupnp_dlna_container_information,
+                          GUPNP_DLNA,
+                          CONTAINER_INFORMATION,
+                          GObject)
+
 #define GUPNP_TYPE_DLNA_CONTAINER_INFORMATION \
         (gupnp_dlna_container_information_get_type())
 
-#define GUPNP_DLNA_CONTAINER_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_CONTAINER_INFORMATION, \
-                                     GUPnPDLNAContainerInformation))
-
-#define GUPNP_DLNA_CONTAINER_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_CONTAINER_INFORMATION, \
-                                  GUPnPDLNAContainerInformationClass))
-
-#define GUPNP_IS_DLNA_CONTAINER_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_CONTAINER_INFORMATION))
-
-#define GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_CONTAINER_INFORMATION))
-
-#define GUPNP_DLNA_CONTAINER_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_CONTAINER_INFORMATION, \
-                                    GUPnPDLNAContainerInformationClass))
-
-typedef struct _GUPnPDLNAContainerInformationPrivate
-                GUPnPDLNAContainerInformationPrivate;
-
-typedef struct {
-        GObject parent;
-
-        GUPnPDLNAContainerInformationPrivate *priv;
-} GUPnPDLNAContainerInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_CONTAINER_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_CONTAINER_INFORMATION GUPNP_DLNA_IS_CONTAINER_INFORMATION
+/**
+ * GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_CONTAINER_INFORMATION_CLASS GUPNP_DLNA_IS_CONTAINER_INFORMATION_CLASS
 
 /**
  * GUPnPDLNAContainerInformationClass:
@@ -79,7 +63,7 @@ typedef struct {
  * type.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAContainerInformationClass {
         GObjectClass parent_class;
 
         GUPnPDLNAIntValue
@@ -101,10 +85,7 @@ typedef struct {
         (* get_mime) (GUPnPDLNAContainerInformation *info);
 
         gpointer _reserved[12];
-} GUPnPDLNAContainerInformationClass;
-
-GType
-gupnp_dlna_container_information_get_type (void);
+};
 
 GUPnPDLNAIntValue
 gupnp_dlna_container_information_get_mpeg_version
diff --git a/libgupnp-dlna/gupnp-dlna-image-information.c b/libgupnp-dlna/gupnp-dlna-image-information.c
index aa36e14..999db40 100644
--- a/libgupnp-dlna/gupnp-dlna-image-information.c
+++ b/libgupnp-dlna/gupnp-dlna-image-information.c
@@ -50,6 +50,8 @@
 struct _GUPnPDLNAImageInformationPrivate {
         gpointer placeholder;
 };
+typedef struct _GUPnPDLNAImageInformationPrivate
+        GUPnPDLNAImageInformationPrivate;
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAImageInformation,
                                      gupnp_dlna_image_information,
@@ -68,10 +70,6 @@ gupnp_dlna_image_information_class_init
 static void
 gupnp_dlna_image_information_init (GUPnPDLNAImageInformation *info)
 {
-        GUPnPDLNAImageInformationPrivate *priv =
-            gupnp_dlna_image_information_get_instance_private (info);
-
-        info->priv = priv;
 }
 
 /**
@@ -85,13 +83,13 @@ gupnp_dlna_image_information_get_depth (GUPnPDLNAImageInformation *info)
 {
         GUPnPDLNAImageInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_IMAGE_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_IMAGE_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_IMAGE_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_depth != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -110,13 +108,13 @@ gupnp_dlna_image_information_get_height (GUPnPDLNAImageInformation *info)
 {
         GUPnPDLNAImageInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_IMAGE_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_IMAGE_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_IMAGE_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_height != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -135,13 +133,13 @@ gupnp_dlna_image_information_get_width (GUPnPDLNAImageInformation *info)
 {
         GUPnPDLNAImageInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_IMAGE_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_IMAGE_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_IMAGE_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_width != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -160,13 +158,13 @@ gupnp_dlna_image_information_get_mime (GUPnPDLNAImageInformation *info)
 {
         GUPnPDLNAImageInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_IMAGE_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_IMAGE_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_IMAGE_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mime != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
diff --git a/libgupnp-dlna/gupnp-dlna-image-information.h b/libgupnp-dlna/gupnp-dlna-image-information.h
index 56b39c3..4608dc8 100644
--- a/libgupnp-dlna/gupnp-dlna-image-information.h
+++ b/libgupnp-dlna/gupnp-dlna-image-information.h
@@ -27,40 +27,25 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_IMAGE_INFORMATION \
-        (gupnp_dlna_image_information_get_type())
-
-#define GUPNP_DLNA_IMAGE_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_IMAGE_INFORMATION, \
-                                     GUPnPDLNAImageInformation))
-
-#define GUPNP_DLNA_IMAGE_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_IMAGE_INFORMATION, \
-                                  GUPnPDLNAImageInformationClass))
-
-#define GUPNP_IS_DLNA_IMAGE_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_IMAGE_INFORMATION))
-
-#define GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_IMAGE_INFORMATION))
-
-#define GUPNP_DLNA_IMAGE_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_IMAGE_INFORMATION, \
-                                    GUPnPDLNAImageInformationClass))
+G_DECLARE_DERIVABLE_TYPE(GUPnPDLNAImageInformation,
+                          gupnp_dlna_image_information,
+                          GUPNP_DLNA,
+                          IMAGE_INFORMATION,
+                          GObject)
 
-typedef struct _GUPnPDLNAImageInformationPrivate
-                GUPnPDLNAImageInformationPrivate;
 
-typedef struct {
-        GObject parent;
+#define GUPNP_TYPE_DLNA_IMAGE_INFORMATION \
+        (gupnp_dlna_image_information_get_type())
 
-        GUPnPDLNAImageInformationPrivate *priv;
-} GUPnPDLNAImageInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_IMAGE_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_IMAGE_INFORMATION GUPNP_DLNA_IS_IMAGE_INFORMATION
+/**
+ * GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_IMAGE_INFORMATION_CLASS GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS
 
 /**
  * GUPnPDLNAImageInformationClass:
@@ -75,7 +60,7 @@ typedef struct {
  * type.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAImageInformationClass {
         GObjectClass parent_class;
 
         GUPnPDLNAIntValue
@@ -91,10 +76,7 @@ typedef struct {
         (* get_mime) (GUPnPDLNAImageInformation *info);
 
         gpointer _reserved[12];
-} GUPnPDLNAImageInformationClass;
-
-GType
-gupnp_dlna_image_information_get_type (void);
+};
 
 GUPnPDLNAIntValue
 gupnp_dlna_image_information_get_depth (GUPnPDLNAImageInformation *info);
diff --git a/libgupnp-dlna/gupnp-dlna-info-value.c b/libgupnp-dlna/gupnp-dlna-info-value.c
index 10cc487..25e50a1 100644
--- a/libgupnp-dlna/gupnp-dlna-info-value.c
+++ b/libgupnp-dlna/gupnp-dlna-info-value.c
@@ -51,10 +51,9 @@ value_new (GUPnPDLNAValueType *type,
 static GUPnPDLNAInfoValue *
 value_unsupported (GUPnPDLNAValueType *type)
 {
-        GUPnPDLNAInfoValue *info_value = g_slice_new (GUPnPDLNAInfoValue);
+        GUPnPDLNAInfoValue *info_value = g_slice_new0 (GUPnPDLNAInfoValue);
 
         info_value->type = type;
-        memset (&info_value->value, 0, sizeof (GUPnPDLNAValueUnion));
         info_value->unsupported = TRUE;
 
         return info_value;
diff --git a/libgupnp-dlna/gupnp-dlna-information.c b/libgupnp-dlna/gupnp-dlna-information.c
index 0334464..dfe613c 100644
--- a/libgupnp-dlna/gupnp-dlna-information.c
+++ b/libgupnp-dlna/gupnp-dlna-information.c
@@ -45,6 +45,7 @@ struct _GUPnPDLNAInformationPrivate {
         GUPnPDLNAImageInformation *image_info;
         GUPnPDLNAVideoInformation *video_info;
 };
+typedef struct _GUPnPDLNAInformationPrivate GUPnPDLNAInformationPrivate;
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAInformation,
                                      gupnp_dlna_information,
@@ -70,7 +71,8 @@ static void
 gupnp_dlna_information_dispose (GObject *object)
 {
         GUPnPDLNAInformation *info = GUPNP_DLNA_INFORMATION (object);
-        GUPnPDLNAInformationPrivate *priv = info->priv;
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
         g_clear_object (&priv->audio_info);
         g_clear_object (&priv->container_info);
@@ -83,8 +85,10 @@ static void
 gupnp_dlna_information_finalize (GObject *object)
 {
         GUPnPDLNAInformation *info = GUPNP_DLNA_INFORMATION (object);
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        g_free (info->priv->uri);
+        g_free (priv->uri);
         G_OBJECT_CLASS (gupnp_dlna_information_parent_class)->finalize (object);
 }
 
@@ -95,7 +99,8 @@ gupnp_dlna_information_set_property (GObject      *object,
                                      GParamSpec   *pspec)
 {
         GUPnPDLNAInformation *info = GUPNP_DLNA_INFORMATION (object);
-        GUPnPDLNAInformationPrivate *priv = info->priv;
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_URI:
@@ -116,7 +121,8 @@ gupnp_dlna_information_get_property (GObject    *object,
                                      GParamSpec *pspec)
 {
         GUPnPDLNAInformation *info = GUPNP_DLNA_INFORMATION (object);
-        GUPnPDLNAInformationPrivate *priv = info->priv;
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_URI:
@@ -238,19 +244,6 @@ gupnp_dlna_information_class_init (GUPnPDLNAInformationClass *info_class)
 static void
 gupnp_dlna_information_init (GUPnPDLNAInformation *info)
 {
-        GUPnPDLNAInformationPrivate *priv =
-            gupnp_dlna_information_get_instance_private (info);
-
-        priv->uri = NULL;
-        priv->got_audio_info = FALSE;
-        priv->got_container_info = FALSE;
-        priv->got_image_info = FALSE;
-        priv->got_video_info = FALSE;
-        priv->audio_info = NULL;
-        priv->container_info = NULL;
-        priv->image_info = NULL;
-        priv->video_info = NULL;
-        info->priv = priv;
 }
 
 /**
@@ -265,18 +258,17 @@ gupnp_dlna_information_init (GUPnPDLNAInformation *info)
 GUPnPDLNAAudioInformation *
 gupnp_dlna_information_get_audio_information (GUPnPDLNAInformation *info)
 {
-        GUPnPDLNAInformationPrivate *priv;
-
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        priv = info->priv;
         if (!priv->got_audio_info) {
                 GUPnPDLNAInformationClass *info_class;
 
                 info_class = GUPNP_DLNA_INFORMATION_GET_CLASS (info);
 
                 g_return_val_if_fail
-                                  (GUPNP_IS_DLNA_INFORMATION_CLASS (info_class),
+                                  (GUPNP_DLNA_IS_INFORMATION_CLASS (info_class),
                                    NULL);
                 g_return_val_if_fail (info_class->get_audio_information != NULL,
                                       NULL);
@@ -300,18 +292,17 @@ gupnp_dlna_information_get_audio_information (GUPnPDLNAInformation *info)
 GUPnPDLNAContainerInformation *
 gupnp_dlna_information_get_container_information (GUPnPDLNAInformation *info)
 {
-        GUPnPDLNAInformationPrivate *priv;
-
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        priv = info->priv;
         if (!priv->got_container_info) {
                 GUPnPDLNAInformationClass *info_class;
 
                 info_class = GUPNP_DLNA_INFORMATION_GET_CLASS (info);
 
                 g_return_val_if_fail
-                                  (GUPNP_IS_DLNA_INFORMATION_CLASS (info_class),
+                                  (GUPNP_DLNA_IS_INFORMATION_CLASS (info_class),
                                    NULL);
                 g_return_val_if_fail
                                  (info_class->get_container_information != NULL,
@@ -337,18 +328,18 @@ gupnp_dlna_information_get_container_information (GUPnPDLNAInformation *info)
 GUPnPDLNAImageInformation *
 gupnp_dlna_information_get_image_information (GUPnPDLNAInformation *info)
 {
-        GUPnPDLNAInformationPrivate *priv;
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        priv = info->priv;
         if (!priv->got_image_info) {
                 GUPnPDLNAInformationClass *info_class;
 
                 info_class = GUPNP_DLNA_INFORMATION_GET_CLASS (info);
 
                 g_return_val_if_fail
-                                  (GUPNP_IS_DLNA_INFORMATION_CLASS (info_class),
+                                  (GUPNP_DLNA_IS_INFORMATION_CLASS (info_class),
                                    NULL);
                 g_return_val_if_fail (info_class->get_image_information != NULL,
                                       NULL);
@@ -372,18 +363,18 @@ gupnp_dlna_information_get_image_information (GUPnPDLNAInformation *info)
 GUPnPDLNAVideoInformation *
 gupnp_dlna_information_get_video_information (GUPnPDLNAInformation *info)
 {
-        GUPnPDLNAInformationPrivate *priv;
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        priv = info->priv;
         if (!priv->got_video_info) {
                 GUPnPDLNAInformationClass *info_class;
 
                 info_class = GUPNP_DLNA_INFORMATION_GET_CLASS (info);
 
                 g_return_val_if_fail
-                                  (GUPNP_IS_DLNA_INFORMATION_CLASS (info_class),
+                                  (GUPNP_DLNA_IS_INFORMATION_CLASS (info_class),
                                    NULL);
                 g_return_val_if_fail (info_class->get_video_information != NULL,
                                       NULL);
@@ -404,7 +395,7 @@ gupnp_dlna_information_get_video_information (GUPnPDLNAInformation *info)
 const gchar *
 gupnp_dlna_information_get_profile_name (GUPnPDLNAInformation *info)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
 
         return GUPNP_DLNA_INFORMATION_GET_CLASS (info)->get_profile_name (info);
 }
@@ -419,7 +410,10 @@ gupnp_dlna_information_get_profile_name (GUPnPDLNAInformation *info)
 const gchar *
 gupnp_dlna_information_get_uri (GUPnPDLNAInformation *info)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
+
+        GUPnPDLNAInformationPrivate *priv =
+                gupnp_dlna_information_get_instance_private (info);
 
-        return info->priv->uri;
+        return priv->uri;
 }
diff --git a/libgupnp-dlna/gupnp-dlna-information.h b/libgupnp-dlna/gupnp-dlna-information.h
index e9c6bf3..335c1cd 100644
--- a/libgupnp-dlna/gupnp-dlna-information.h
+++ b/libgupnp-dlna/gupnp-dlna-information.h
@@ -30,38 +30,23 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_INFORMATION (gupnp_dlna_information_get_type())
-
-#define GUPNP_DLNA_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_INFORMATION, \
-                                     GUPnPDLNAInformation))
-
-#define GUPNP_DLNA_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_INFORMATION, \
-                                  GUPnPDLNAInformationClass))
-
-#define GUPNP_IS_DLNA_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_INFORMATION))
-
-#define GUPNP_IS_DLNA_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_INFORMATION))
-
-#define GUPNP_DLNA_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_INFORMATION, \
-                                    GUPnPDLNAInformationClass))
-
-typedef struct _GUPnPDLNAInformationPrivate GUPnPDLNAInformationPrivate;
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAInformation,
+                          gupnp_dlna_information,
+                          GUPNP_DLNA,
+                          INFORMATION,
+                          GObject)
 
-typedef struct {
-        GObject parent;
+#define GUPNP_TYPE_DLNA_INFORMATION (gupnp_dlna_information_get_type())
 
-        GUPnPDLNAInformationPrivate *priv;
-} GUPnPDLNAInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_INFORMATION GUPNP_DLNA_IS_INFORMATION
+/**
+ * GUPNP_IS_DLNA_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_INFORMATION_CLASS GUPNP_DLNA_IS_INFORMATION_CLASS
 
 /**
  * GUPnPDLNAInformationClass:
@@ -78,7 +63,7 @@ typedef struct {
  * get the name of the DLNA profile assigned with this information.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAInformationClass{
         GObjectClass parent_class;
 
         GUPnPDLNAAudioInformation *
@@ -97,10 +82,7 @@ typedef struct {
         (* get_profile_name) (GUPnPDLNAInformation *info);
 
         gpointer _reserved[11];
-} GUPnPDLNAInformationClass;
-
-GType
-gupnp_dlna_information_get_type (void);
+};
 
 GUPnPDLNAAudioInformation*
 gupnp_dlna_information_get_audio_information (GUPnPDLNAInformation *info);
diff --git a/libgupnp-dlna/gupnp-dlna-profile-guesser.c b/libgupnp-dlna/gupnp-dlna-profile-guesser.c
index 757802b..c9d815a 100644
--- a/libgupnp-dlna/gupnp-dlna-profile-guesser.c
+++ b/libgupnp-dlna/gupnp-dlna-profile-guesser.c
@@ -47,6 +47,7 @@ struct _GUPnPDLNAProfileGuesserPrivate {
         gboolean relaxed_mode;
         gboolean extended_mode;
 };
+typedef struct _GUPnPDLNAProfileGuesserPrivate GUPnPDLNAProfileGuesserPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAProfileGuesser,
                             gupnp_dlna_profile_guesser,
@@ -67,7 +68,8 @@ gupnp_dlna_profile_guesser_set_property (GObject      *object,
                                          GParamSpec   *pspec)
 {
         GUPnPDLNAProfileGuesser *self = GUPNP_DLNA_PROFILE_GUESSER (object);
-        GUPnPDLNAProfileGuesserPrivate *priv = self->priv;
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (self);
 
         switch (property_id) {
         case PROP_DLNA_RELAXED_MODE:
@@ -93,7 +95,8 @@ gupnp_dlna_profile_guesser_get_property (GObject    *object,
                                          GParamSpec *pspec)
 {
         GUPnPDLNAProfileGuesser *self = GUPNP_DLNA_PROFILE_GUESSER (object);
-        GUPnPDLNAProfileGuesserPrivate *priv = self->priv;
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (self);
 
         switch (property_id) {
         case PROP_DLNA_RELAXED_MODE:
@@ -202,12 +205,6 @@ gupnp_dlna_profile_guesser_class_init
 static void
 gupnp_dlna_profile_guesser_init (GUPnPDLNAProfileGuesser *self)
 {
-        GUPnPDLNAProfileGuesserPrivate *priv =
-            gupnp_dlna_profile_guesser_get_instance_private (self);
-
-        priv->relaxed_mode = FALSE;
-        priv->extended_mode = FALSE;
-        self->priv = priv;
 }
 
 /**
@@ -285,7 +282,7 @@ gupnp_dlna_profile_guesser_guess_profile_async
         GError *extractor_error;
         guint id;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), FALSE);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), FALSE);
         g_return_val_if_fail (uri != NULL, FALSE);
         g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 
@@ -338,7 +335,7 @@ gupnp_dlna_profile_guesser_guess_profile_sync
         GUPnPDLNAInformation *info;
         GUPnPDLNAProfile *profile;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), NULL);
         g_return_val_if_fail (uri != NULL, NULL);
         g_return_val_if_fail (dlna_info == NULL || *dlna_info == NULL, NULL);
         g_return_val_if_fail (error == NULL || *error == NULL, NULL);
@@ -402,8 +399,8 @@ gupnp_dlna_profile_guesser_guess_profile_from_info
         GUPnPDLNAProfile *profile;
         const gchar *profile_name;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), NULL);
-        g_return_val_if_fail (GUPNP_IS_DLNA_INFORMATION (info), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_INFORMATION (info), NULL);
 
         profiles = gupnp_dlna_profile_guesser_list_profiles (guesser);
         video_info = gupnp_dlna_information_get_video_information (info);
@@ -457,12 +454,12 @@ gupnp_dlna_profile_guesser_get_profile (GUPnPDLNAProfileGuesser *guesser,
 {
         // TODO: use a GHashTable for this.
         GList *iter;
-        GUPnPDLNAProfileGuesserPrivate *priv;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), NULL);
         g_return_val_if_fail (name != NULL, NULL);
 
-        priv = guesser->priv;
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (guesser);
 
         for (iter = profiles_list[priv->relaxed_mode][priv->extended_mode];
              iter;
@@ -489,11 +486,10 @@ gupnp_dlna_profile_guesser_get_profile (GUPnPDLNAProfileGuesser *guesser,
 GList *
 gupnp_dlna_profile_guesser_list_profiles (GUPnPDLNAProfileGuesser *guesser)
 {
-        GUPnPDLNAProfileGuesserPrivate *priv;
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), NULL);
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), NULL);
-
-        priv = guesser->priv;
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (guesser);
 
         return profiles_list[priv->relaxed_mode][priv->extended_mode];
 }
@@ -507,9 +503,11 @@ gupnp_dlna_profile_guesser_list_profiles (GUPnPDLNAProfileGuesser *guesser)
 gboolean
 gupnp_dlna_profile_guesser_get_relaxed_mode (GUPnPDLNAProfileGuesser *guesser)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), FALSE);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), FALSE);
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (guesser);
 
-        return guesser->priv->relaxed_mode;
+        return priv->relaxed_mode;
 }
 
 /**
@@ -521,9 +519,11 @@ gupnp_dlna_profile_guesser_get_relaxed_mode (GUPnPDLNAProfileGuesser *guesser)
 gboolean
 gupnp_dlna_profile_guesser_get_extended_mode (GUPnPDLNAProfileGuesser *guesser)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_GUESSER (guesser), FALSE);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_GUESSER (guesser), FALSE);
+        GUPnPDLNAProfileGuesserPrivate *priv =
+                gupnp_dlna_profile_guesser_get_instance_private (guesser);
 
-        return guesser->priv->extended_mode;
+        return priv->extended_mode;
 }
 
 /**
diff --git a/libgupnp-dlna/gupnp-dlna-profile-guesser.h b/libgupnp-dlna/gupnp-dlna-profile-guesser.h
index a9a4907..d6ee189 100644
--- a/libgupnp-dlna/gupnp-dlna-profile-guesser.h
+++ b/libgupnp-dlna/gupnp-dlna-profile-guesser.h
@@ -32,52 +32,29 @@ G_BEGIN_DECLS
 
 #define GUPNP_TYPE_DLNA_PROFILE_GUESSER (gupnp_dlna_profile_guesser_get_type())
 
-#define GUPNP_DLNA_PROFILE_GUESSER(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE_GUESSER, \
-                                     GUPnPDLNAProfileGuesser))
-
-#define GUPNP_DLNA_PROFILE_GUESSER_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE_GUESSER, \
-                                  GUPnPDLNAProfileGuesserClass))
-
-#define GUPNP_IS_DLNA_PROFILE_GUESSER(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE_GUESSER))
-
-#define GUPNP_IS_DLNA_PROFILE_GUESSER_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE_GUESSER))
-
-#define GUPNP_DLNA_PROFILE_GUESSER_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_PROFILE_GUESSER, \
-                                    GUPnPDLNAProfileGuesserClass))
-
-typedef struct _GUPnPDLNAProfileGuesserPrivate GUPnPDLNAProfileGuesserPrivate;
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAProfileGuesser,
+                          gupnp_dlna_profile_guesser,
+                          GUPNP_DLNA,
+                          PROFILE_GUESSER,
+                          GObject)
 
+// Backwards-compatible defines
 /**
- * GUPnPDLNAProfileGuesser:
- *
- * The top-level object used to for DLNA profile guessing.
+ * GUPNP_IS_DLNA_PROFILE_GUESSER: (skip)
  */
-typedef struct {
-        GObject parent;
-
-        GUPnPDLNAProfileGuesserPrivate *priv;
-} GUPnPDLNAProfileGuesser;
+#define GUPNP_IS_DLNA_PROFILE_GUESSER GUPNP_DLNA_IS_PROFILE_GUESSER
+/**
+ * GUPNP_IS_DLNA_PROFILE_GUESSER_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_PROFILE_GUESSER_CLASS GUPNP_DLNA_IS_PROFILE_GUESSER_CLASS
 
 /**
  * GUPnPDLNAProfileGuesserClass:
  * @parent_class: A #GObjectClass - parent of this class.
  */
-typedef struct {
+struct _GUPnPDLNAProfileGuesserClass {
         GObjectClass parent_class;
-} GUPnPDLNAProfileGuesserClass;
-
-GType
-gupnp_dlna_profile_guesser_get_type (void) G_GNUC_CONST;
+};
 
 GUPnPDLNAProfileGuesser *
 gupnp_dlna_profile_guesser_new (gboolean relaxed_mode,
diff --git a/libgupnp-dlna/gupnp-dlna-profile-loader.c b/libgupnp-dlna/gupnp-dlna-profile-loader.c
index f4d7a0f..fae7c09 100644
--- a/libgupnp-dlna/gupnp-dlna-profile-loader.c
+++ b/libgupnp-dlna/gupnp-dlna-profile-loader.c
@@ -48,6 +48,7 @@ struct _GUPnPDLNAProfileLoaderPrivate {
         GList      *restriction_data_stack;
         char       *dlna_profile_dir;
 };
+typedef struct _GUPnPDLNAProfileLoaderPrivate GUPnPDLNAProfileLoaderPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAProfileLoader,
                             gupnp_dlna_profile_loader,
@@ -220,7 +221,9 @@ static void
 push_tag (GUPnPDLNAProfileLoader *loader,
           GUPnPDLNAParsedElement  element)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+            gupnp_dlna_profile_loader_get_instance_private (loader);
+
         gint raw_element = (gint) element;
 
         priv->tags_stack = g_list_prepend (priv->tags_stack,
@@ -230,7 +233,8 @@ push_tag (GUPnPDLNAProfileLoader *loader,
 static void
 pop_tag (GUPnPDLNAProfileLoader *loader)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         priv->tags_stack = g_list_delete_link (priv->tags_stack,
                                                priv->tags_stack);
@@ -239,7 +243,8 @@ pop_tag (GUPnPDLNAProfileLoader *loader)
 static GUPnPDLNAParsedElement
 top_tag (GUPnPDLNAProfileLoader *loader)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         if (priv->tags_stack != NULL) {
                 gint top_raw = GPOINTER_TO_INT (priv->tags_stack->data);
@@ -314,7 +319,6 @@ post_field (GUPnPDLNAProfileLoader *loader,
             const gchar            *type,
             GList                  *values)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv;
         GUPnPDLNARestrictionData *restriction_data;
         GUPnPDLNANameValueListPair *pair;
         GUPnPDLNAValueList *value_list;
@@ -331,7 +335,8 @@ post_field (GUPnPDLNAProfileLoader *loader,
         if (value_type == NULL)
                 return;
 
-        priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         restriction_data =
                 (GUPnPDLNARestrictionData *) priv->restriction_data_stack->data;
         value_list = gupnp_dlna_value_list_new (value_type);
@@ -353,7 +358,8 @@ static void
 merge_restrictions (GUPnPDLNAProfileLoader *loader,
                     GUPnPDLNADescription   *description)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNAProfileData* data =
                    (GUPnPDLNAProfileData *) priv->dlna_profile_data_stack->data;
         GList **target_list;
@@ -402,7 +408,8 @@ static void
 collect_parents (GUPnPDLNAProfileLoader *loader,
                  GUPnPDLNADescription   *description)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNARestrictionData *data =
                 (GUPnPDLNARestrictionData *) priv->restriction_data_stack->data;
 
@@ -436,7 +443,8 @@ static void
 post_parent (GUPnPDLNAProfileLoader *loader,
              const gchar            *parent)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         pop_tag (loader);
 
@@ -453,7 +461,8 @@ post_parent (GUPnPDLNAProfileLoader *loader,
 static void
 pre_restriction (GUPnPDLNAProfileLoader *loader)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNARestrictionData *data = gupnp_dlna_restriction_data_new ();
 
         push_tag (loader, GUPNP_DLNA_PARSED_ELEMENT_RESTRICTION);
@@ -484,7 +493,8 @@ post_restriction (GUPnPDLNAProfileLoader *loader,
                   const gchar            *id,
                   const gchar            *name)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNARestrictionData *data =
                 (GUPnPDLNARestrictionData *) priv->restriction_data_stack->data;
         GUPnPDLNARestriction *restriction;
@@ -563,7 +573,8 @@ post_restrictions (GUPnPDLNAProfileLoader *loader)
 static void
 pre_dlna_profile (GUPnPDLNAProfileLoader *loader)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNAProfileData* data = gupnp_dlna_profile_data_new ();
 
         push_tag (loader, GUPNP_DLNA_PARSED_ELEMENT_DLNA_PROFILE);
@@ -650,7 +661,8 @@ create_profile (GUPnPDLNAProfileLoader *loader,
                 const gchar            *mime,
                 gboolean                extended)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNAProfileData *data =
                    (GUPnPDLNAProfileData *) priv->dlna_profile_data_stack->data;
         GList *audio_restrictions = NULL;
@@ -692,7 +704,8 @@ create_profile (GUPnPDLNAProfileLoader *loader,
 static void
 post_dlna_profile (GUPnPDLNAProfileLoader *loader)
 {
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
         GUPnPDLNAProfileData *data =
                    (GUPnPDLNAProfileData *) priv->dlna_profile_data_stack->data;
 
@@ -764,7 +777,8 @@ gupnp_dlna_profile_loader_get_property (GObject    *object,
                                         GParamSpec *pspec)
 {
         GUPnPDLNAProfileLoader *loader = GUPNP_DLNA_PROFILE_LOADER (object);
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         switch (prop_id) {
         case PROP_RELAXED_MODE:
@@ -787,7 +801,8 @@ gupnp_dlna_profile_loader_set_property (GObject      *object,
                                         GParamSpec   *pspec)
 {
         GUPnPDLNAProfileLoader *loader = GUPNP_DLNA_PROFILE_LOADER (object);
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         switch (prop_id) {
         case PROP_RELAXED_MODE:
@@ -807,7 +822,8 @@ static void
 gupnp_dlna_profile_loader_dispose (GObject *object)
 {
         GUPnPDLNAProfileLoader *loader = GUPNP_DLNA_PROFILE_LOADER (object);
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         g_clear_pointer (&priv->restrictions, g_hash_table_unref);
         g_clear_pointer (&priv->profile_ids, g_hash_table_unref);
@@ -884,11 +900,6 @@ gupnp_dlna_profile_loader_init (GUPnPDLNAProfileLoader *self)
                                   g_str_equal,
                                   g_free,
                                   (GDestroyNotify) gupnp_dlna_description_free);
-        priv->tags_stack = NULL;
-        priv->dlna_profile_data_stack = NULL;
-        priv->restriction_data_stack = NULL;
-
-        self->priv = priv;
 }
 
 static GUPnPDLNAFieldValue *
@@ -981,7 +992,8 @@ process_field (GUPnPDLNAProfileLoader *loader,
         gboolean done = FALSE;
         gboolean skip = FALSE;
         GUPnPDLNAFieldValue *value = NULL;
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         pre_field (loader);
 
@@ -1066,7 +1078,8 @@ process_parent (GUPnPDLNAProfileLoader *loader,
 {
         xmlChar *parent = NULL;
         xmlChar *used = NULL;
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         pre_parent (loader);
 
@@ -1112,7 +1125,8 @@ process_restriction (GUPnPDLNAProfileLoader *loader,
         xmlChar *id = NULL;
         xmlChar *type = NULL;
         gchar *name = NULL;
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         pre_restriction (loader);
         /*
@@ -1258,7 +1272,8 @@ process_dlna_profile (GUPnPDLNAProfileLoader  *loader,
         xmlChar *extended;
         gboolean done = FALSE;
         gboolean is_extended = FALSE;
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
         pre_dlna_profile (loader);
 
@@ -1368,9 +1383,10 @@ process_include (GUPnPDLNAProfileLoader  *loader,
                 xmlFree (path);
 
         if (!g_path_is_absolute (g_path)) {
-                gchar *tmp = g_build_filename (loader->priv->dlna_profile_dir,
-                                               g_path,
-                                               NULL);
+                GUPnPDLNAProfileLoaderPrivate *priv =
+                        gupnp_dlna_profile_loader_get_instance_private (loader);
+                gchar *tmp =
+                        g_build_filename (priv->dlna_profile_dir, g_path, NULL);
                 g_free (g_path);
                 g_path = tmp;
         }
@@ -1431,7 +1447,9 @@ gupnp_dlna_profile_loader_get_from_file (GUPnPDLNAProfileLoader  *loader,
         xmlTextReaderPtr reader = NULL;
         xmlRelaxNGParserCtxtPtr rngp = NULL;
         xmlRelaxNGPtr rngs = NULL;
-        GUPnPDLNAProfileLoaderPrivate *priv = loader->priv;
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
+
         char *rng_path = NULL;
 
         if (g_hash_table_contains (priv->files_hash, path))
@@ -1444,7 +1462,7 @@ gupnp_dlna_profile_loader_get_from_file (GUPnPDLNAProfileLoader  *loader,
                 goto out;
 
         /* Load the schema for validation */
-        rng_path = g_build_filename (loader->priv->dlna_profile_dir,
+        rng_path = g_build_filename (priv->dlna_profile_dir,
                                      "dlna-profiles.rng",
                                      NULL);
         rngp = xmlRelaxNGNewParserCtxt (rng_path);
@@ -1552,27 +1570,29 @@ gupnp_dlna_profile_loader_get_from_disk (GUPnPDLNAProfileLoader *loader)
 {
         GList *profiles;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE_LOADER (loader), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE_LOADER (loader), NULL);
+        GUPnPDLNAProfileLoaderPrivate *priv =
+                gupnp_dlna_profile_loader_get_instance_private (loader);
 
-        if (loader->priv->dlna_profile_dir == NULL) {
+        if (priv->dlna_profile_dir == NULL) {
                 char **env = NULL;
                 const char *profile_dir = NULL;
 
                 env = g_get_environ ();
                 profile_dir = g_environ_getenv (env, "GUPNP_DLNA_PROFILE_DIR");
                 if (profile_dir != NULL && g_path_is_absolute (profile_dir)) {
-                        loader->priv->dlna_profile_dir = g_strdup (profile_dir);
+                        priv->dlna_profile_dir = g_strdup (profile_dir);
                 } else {
-                        loader->priv->dlna_profile_dir = g_strdup (DLNA_DATA_DIR);
+                        priv->dlna_profile_dir = g_strdup (DLNA_DATA_DIR);
                 }
 
 
                 g_strfreev (env);
         }
 
-        profiles = gupnp_dlna_profile_loader_get_from_dir
-                                        (loader,
-                                         loader->priv->dlna_profile_dir);
+        profiles =
+                gupnp_dlna_profile_loader_get_from_dir (loader,
+                                                        priv->dlna_profile_dir);
 
         profiles = g_list_reverse (profiles);
 
diff --git a/libgupnp-dlna/gupnp-dlna-profile-loader.h b/libgupnp-dlna/gupnp-dlna-profile-loader.h
index 68e72d1..635e6d3 100644
--- a/libgupnp-dlna/gupnp-dlna-profile-loader.h
+++ b/libgupnp-dlna/gupnp-dlna-profile-loader.h
@@ -31,45 +31,29 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_PROFILE_LOADER (gupnp_dlna_profile_loader_get_type ())
-
-#define GUPNP_DLNA_PROFILE_LOADER(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE_LOADER, \
-                                     GUPnPDLNAProfileLoader))
-
-#define GUPNP_DLNA_PROFILE_LOADER_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE_LOADER, \
-                                  GUPnPDLNAProfileLoaderClass))
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAProfileLoader,
+                          gupnp_dlna_profile_loader,
+                          GUPNP_DLNA,
+                          PROFILE_LOADER,
+                          GObject)
 
-#define GUPNP_IS_DLNA_PROFILE_LOADER(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE_LOADER))
 
-#define GUPNP_IS_DLNA_PROFILE_LOADER_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE_LOADER))
-
-#define GUPNP_DLNA_PROFILE_LOADER_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_PROFILE_LOADER, \
-                                    GUPnPDLNAProfileLoaderClass))
+#define GUPNP_TYPE_DLNA_PROFILE_LOADER (gupnp_dlna_profile_loader_get_type ())
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_PROFILE_LOADER: (skip)
+ */
+#define GUPNP_IS_DLNA_PROFILE_LOADER GUPNP_DLNA_IS_PROFILE_LOADER
+/**
+ * GUPNP_IS_DLNA_PROFILE_LOADER_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_PROFILE_LOADER_CLASS GUPNP_DLNA_IS_PROFILE_LOADER_CLASS
 
 typedef struct _GUPnPDLNAProfileLoaderPrivate GUPnPDLNAProfileLoaderPrivate;
 
-typedef struct {
-        GObject parent;
-
-        GUPnPDLNAProfileLoaderPrivate *priv;
-} GUPnPDLNAProfileLoader;
-
-typedef struct {
+struct _GUPnPDLNAProfileLoaderClass {
         GObjectClass parent_class;
-} GUPnPDLNAProfileLoaderClass;
-
-GType
-gupnp_dlna_profile_loader_get_type (void);
+};
 
 GUPnPDLNAProfileLoader *
 gupnp_dlna_profile_loader_new (gboolean relaxed_mode,
diff --git a/libgupnp-dlna/gupnp-dlna-profile.c b/libgupnp-dlna/gupnp-dlna-profile.c
index eb190a9..8f215a7 100644
--- a/libgupnp-dlna/gupnp-dlna-profile.c
+++ b/libgupnp-dlna/gupnp-dlna-profile.c
@@ -37,6 +37,13 @@
  * restrictions specified for that DLNA profile is to be added.
  */
 
+/**
+ * GUPnPDLNAProfile:
+ *
+ * The top-level object used for the in-memory representation of the
+ * DLNA Profiles.
+ */
+
 struct _GUPnPDLNAProfilePrivate {
         gchar    *name;
         gchar    *mime;
@@ -46,6 +53,7 @@ struct _GUPnPDLNAProfilePrivate {
         GList    *image_restrictions;
         GList    *video_restrictions;
 };
+typedef struct _GUPnPDLNAProfilePrivate GUPnPDLNAProfilePrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAProfile, gupnp_dlna_profile, G_TYPE_OBJECT)
 
@@ -67,7 +75,8 @@ gupnp_dlna_profile_get_property (GObject    *object,
                                  GParamSpec *pspec)
 {
         GUPnPDLNAProfile *profile = GUPNP_DLNA_PROFILE (object);
-        GUPnPDLNAProfilePrivate *priv = profile->priv;
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
         switch (property_id) {
         case PROP_DLNA_NAME:
@@ -122,7 +131,8 @@ gupnp_dlna_profile_set_property (GObject      *object,
                                  GParamSpec   *pspec)
 {
         GUPnPDLNAProfile *profile = GUPNP_DLNA_PROFILE (object);
-        GUPnPDLNAProfilePrivate *priv = profile->priv;
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
         switch (property_id) {
         case PROP_DLNA_NAME:
@@ -170,7 +180,8 @@ static void
 gupnp_dlna_profile_finalize (GObject *object)
 {
         GUPnPDLNAProfile *profile = GUPNP_DLNA_PROFILE (object);
-        GUPnPDLNAProfilePrivate *priv = profile->priv;
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
         g_free (priv->name);
         g_free (priv->mime);
@@ -271,17 +282,6 @@ gupnp_dlna_profile_class_init (GUPnPDLNAProfileClass *klass)
 static void
 gupnp_dlna_profile_init (GUPnPDLNAProfile *profile)
 {
-        GUPnPDLNAProfilePrivate *priv =
-            gupnp_dlna_profile_get_instance_private (profile);
-
-        priv->name = NULL;
-        priv->mime = NULL;
-        priv->extended = FALSE;
-        priv->audio_restrictions = NULL;
-        priv->container_restrictions = NULL;
-        priv->image_restrictions = NULL;
-        priv->video_restrictions = NULL;
-        profile->priv = priv;
 }
 
 /**
@@ -293,9 +293,11 @@ gupnp_dlna_profile_init (GUPnPDLNAProfile *profile)
 const gchar *
 gupnp_dlna_profile_get_name (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->name;
+        return priv->name;
 }
 
 /**
@@ -307,9 +309,11 @@ gupnp_dlna_profile_get_name (GUPnPDLNAProfile *profile)
 const gchar *
 gupnp_dlna_profile_get_mime (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->mime;
+        return priv->mime;
 }
 
 /**
@@ -321,9 +325,11 @@ gupnp_dlna_profile_get_mime (GUPnPDLNAProfile *profile)
 gboolean
 gupnp_dlna_profile_get_extended (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), FALSE);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), FALSE);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->extended;
+        return priv->extended;
 }
 
 /**
@@ -338,9 +344,11 @@ gupnp_dlna_profile_get_extended (GUPnPDLNAProfile *profile)
 GList *
 gupnp_dlna_profile_get_audio_restrictions (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->audio_restrictions;
+        return priv->audio_restrictions;
 }
 
 /**
@@ -355,9 +363,11 @@ gupnp_dlna_profile_get_audio_restrictions (GUPnPDLNAProfile *profile)
 GList *
 gupnp_dlna_profile_get_container_restrictions (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->container_restrictions;
+        return priv->container_restrictions;
 }
 
 /**
@@ -372,9 +382,11 @@ gupnp_dlna_profile_get_container_restrictions (GUPnPDLNAProfile *profile)
 GList *
 gupnp_dlna_profile_get_image_restrictions (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->image_restrictions;
+        return priv->image_restrictions;
 }
 
 /**
@@ -389,9 +401,11 @@ gupnp_dlna_profile_get_image_restrictions (GUPnPDLNAProfile *profile)
 GList *
 gupnp_dlna_profile_get_video_restrictions (GUPnPDLNAProfile *profile)
 {
-        g_return_val_if_fail (GUPNP_IS_DLNA_PROFILE (profile), NULL);
+        g_return_val_if_fail (GUPNP_DLNA_IS_PROFILE (profile), NULL);
+        GUPnPDLNAProfilePrivate *priv =
+                gupnp_dlna_profile_get_instance_private (profile);
 
-        return profile->priv->video_restrictions;
+        return priv->video_restrictions;
 }
 
 GUPnPDLNAProfile *
diff --git a/libgupnp-dlna/gupnp-dlna-profile.h b/libgupnp-dlna/gupnp-dlna-profile.h
index 7f400ed..5a649cf 100644
--- a/libgupnp-dlna/gupnp-dlna-profile.h
+++ b/libgupnp-dlna/gupnp-dlna-profile.h
@@ -29,55 +29,31 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_PROFILE gupnp_dlna_profile_get_type()
-
-#define GUPNP_DLNA_PROFILE(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE, \
-                                     GUPnPDLNAProfile))
-
-#define GUPNP_DLNA_PROFILE_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE, \
-                                  GUPnPDLNAProfileClass))
-
-#define GUPNP_IS_DLNA_PROFILE(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_PROFILE))
-
-#define GUPNP_IS_DLNA_PROFILE_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_PROFILE))
-
-#define GUPNP_DLNA_PROFILE_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_PROFILE, \
-                                    GUPnPDLNAProfileClass))
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAProfile,
+                          gupnp_dlna_profile,
+                          GUPNP_DLNA,
+                          PROFILE,
+                          GObject)
 
-typedef struct _GUPnPDLNAProfilePrivate GUPnPDLNAProfilePrivate;
+#define GUPNP_TYPE_DLNA_PROFILE gupnp_dlna_profile_get_type()
 
+// Backwards-compatible defines
 /**
- * GUPnPDLNAProfile:
- *
- * The top-level object used for the in-memory representation of the
- * DLNA Profiles.
+ * GUPNP_IS_DLNA_PROFILE: (skip)
  */
-typedef struct {
-        GObject parent;
-
-        GUPnPDLNAProfilePrivate *priv;
-} GUPnPDLNAProfile;
+#define GUPNP_IS_DLNA_PROFILE GUPNP_DLNA_IS_PROFILE
+/**
+ * GUPNP_IS_DLNA_PROFILE_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_PROFILE_CLASS GUPNP_DLNA_IS_PROFILE_CLASS
 
 /**
  * GUPnPDLNAProfileClass:
  * @parent_class: A #GObjectClass - parent of this class.
  */
-typedef struct {
+struct _GUPnPDLNAProfileClass {
         GObjectClass parent_class;
-} GUPnPDLNAProfileClass;
-
-GType
-gupnp_dlna_profile_get_type (void);
+};
 
 const gchar *
 gupnp_dlna_profile_get_name (GUPnPDLNAProfile *profile);
diff --git a/libgupnp-dlna/gupnp-dlna-video-information.c b/libgupnp-dlna/gupnp-dlna-video-information.c
index 6a0df92..08a4373 100644
--- a/libgupnp-dlna/gupnp-dlna-video-information.c
+++ b/libgupnp-dlna/gupnp-dlna-video-information.c
@@ -52,6 +52,9 @@ struct _GUPnPDLNAVideoInformationPrivate {
         gpointer placeholder;
 };
 
+typedef struct _GUPnPDLNAVideoInformationPrivate
+        GUPnPDLNAVideoInformationPrivate;
+
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAVideoInformation,
                                      gupnp_dlna_video_information,
                                      G_TYPE_OBJECT)
@@ -76,10 +79,6 @@ gupnp_dlna_video_information_class_init
 static void
 gupnp_dlna_video_information_init (GUPnPDLNAVideoInformation *info)
 {
-        GUPnPDLNAVideoInformationPrivate *priv =
-            gupnp_dlna_video_information_get_instance_private (info);
-
-        info->priv = priv;
 }
 
 /**
@@ -93,13 +92,13 @@ gupnp_dlna_video_information_get_bitrate (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_bitrate != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -118,13 +117,13 @@ gupnp_dlna_video_information_get_framerate (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_FRACTION_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_FRACTION_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_framerate != NULL,
                               GUPNP_DLNA_FRACTION_VALUE_UNSET);
@@ -143,13 +142,13 @@ gupnp_dlna_video_information_get_height (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_height != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -168,13 +167,13 @@ gupnp_dlna_video_information_is_interlaced (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_BOOL_VALUE_UNSET);
         g_return_val_if_fail (info_class->is_interlaced != NULL,
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
@@ -193,13 +192,13 @@ gupnp_dlna_video_information_get_level (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_level != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -218,13 +217,13 @@ gupnp_dlna_video_information_get_mpeg_version (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mpeg_version != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -244,13 +243,13 @@ gupnp_dlna_video_information_get_pixel_aspect_ratio
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_FRACTION_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_FRACTION_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_pixel_aspect_ratio != NULL,
                               GUPNP_DLNA_FRACTION_VALUE_UNSET);
@@ -269,13 +268,13 @@ gupnp_dlna_video_information_get_profile (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_profile != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
@@ -294,13 +293,13 @@ gupnp_dlna_video_information_is_system_stream (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_BOOL_VALUE_UNSET);
         g_return_val_if_fail (info_class->is_system_stream != NULL,
                               GUPNP_DLNA_BOOL_VALUE_UNSET);
@@ -319,13 +318,13 @@ gupnp_dlna_video_information_get_width (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_INT_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_INT_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_width != NULL,
                               GUPNP_DLNA_INT_VALUE_UNSET);
@@ -344,13 +343,13 @@ gupnp_dlna_video_information_get_mime (GUPnPDLNAVideoInformation *info)
 {
         GUPnPDLNAVideoInformationClass *info_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_VIDEO_INFORMATION (info),
+        g_return_val_if_fail (GUPNP_DLNA_IS_VIDEO_INFORMATION (info),
                               GUPNP_DLNA_STRING_VALUE_UNSET);
 
         info_class = GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS (info);
 
         g_return_val_if_fail
-                            (GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS (info_class),
+                            (GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS (info_class),
                              GUPNP_DLNA_STRING_VALUE_UNSET);
         g_return_val_if_fail (info_class->get_mime != NULL,
                               GUPNP_DLNA_STRING_VALUE_UNSET);
diff --git a/libgupnp-dlna/gupnp-dlna-video-information.h b/libgupnp-dlna/gupnp-dlna-video-information.h
index 778d631..c91d352 100644
--- a/libgupnp-dlna/gupnp-dlna-video-information.h
+++ b/libgupnp-dlna/gupnp-dlna-video-information.h
@@ -27,40 +27,25 @@
 
 G_BEGIN_DECLS
 
-#define GUPNP_TYPE_DLNA_VIDEO_INFORMATION \
-        (gupnp_dlna_video_information_get_type())
-
-#define GUPNP_DLNA_VIDEO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_VIDEO_INFORMATION, \
-                                     GUPnPDLNAVideoInformation))
-
-#define GUPNP_DLNA_VIDEO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_VIDEO_INFORMATION, \
-                                  GUPnPDLNAVideoInformationClass))
-
-#define GUPNP_IS_DLNA_VIDEO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_VIDEO_INFORMATION))
-
-#define GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_VIDEO_INFORMATION))
-
-#define GUPNP_DLNA_VIDEO_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_VIDEO_INFORMATION, \
-                                    GUPnPDLNAVideoInformationClass))
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAVideoInformation,
+                          gupnp_dlna_video_information,
+                          GUPNP_DLNA,
+                          VIDEO_INFORMATION,
+                          GObject)
 
-typedef struct _GUPnPDLNAVideoInformationPrivate
-                GUPnPDLNAVideoInformationPrivate;
 
-typedef struct {
-        GObject parent;
+#define GUPNP_TYPE_DLNA_VIDEO_INFORMATION \
+        (gupnp_dlna_video_information_get_type())
 
-        GUPnPDLNAVideoInformationPrivate *priv;
-} GUPnPDLNAVideoInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_VIDEO_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_VIDEO_INFORMATION GUPNP_DLNA_IS_VIDEO_INFORMATION
+/**
+ * GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS GUPNP_DLNA_IS_VIDEO_INFORMATION_CLASS
 
 /**
  * GUPnPDLNAVideoInformationClass:
@@ -89,7 +74,7 @@ typedef struct {
  * type.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAVideoInformationClass {
         GObjectClass parent_class;
 
         GUPnPDLNAIntValue
@@ -126,10 +111,7 @@ typedef struct {
         (* get_mime) (GUPnPDLNAVideoInformation *info);
 
         gpointer _reserved[12];
-} GUPnPDLNAVideoInformationClass;
-
-GType
-gupnp_dlna_video_information_get_type (void);
+};
 
 GUPnPDLNAIntValue
 gupnp_dlna_video_information_get_bitrate (GUPnPDLNAVideoInformation *info);
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.c
index 0f8a5a0..512d3e1 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.c
@@ -25,12 +25,19 @@
 #include "gupnp-dlna-gst-audio-information.h"
 #include "gupnp-dlna-gst-info-utils.h"
 
+
 struct _GUPnPDLNAGstAudioInformationPrivate {
         GstDiscovererInfo *info;
         GList *stream_list;
         GstDiscovererAudioInfo *audio_info;
         GstCaps *caps;
 };
+typedef struct _GUPnPDLNAGstAudioInformationPrivate
+        GUPnPDLNAGstAudioInformationPrivate;
+
+struct _GUPnPDLNAGstAudioInformation {
+        GObject parent;
+};
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstAudioInformation,
                             gupnp_dlna_gst_audio_information,
@@ -46,7 +53,9 @@ enum
 static GstDiscovererAudioInfo *
 get_audio_info (GUPnPDLNAGstAudioInformation *gst_info)
 {
-        GUPnPDLNAGstAudioInformationPrivate *priv = gst_info->priv;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (
+                        gst_info);
 
         if (!priv->audio_info) {
                 GList *iter;
@@ -103,8 +112,10 @@ get_audio_info (GUPnPDLNAGstAudioInformation *gst_info)
 static GstCaps *
 get_caps (GUPnPDLNAGstAudioInformation *gst_info)
 {
-        GUPnPDLNAGstAudioInformationPrivate *priv = gst_info->priv;
         GstDiscovererStreamInfo *info = GST_DISCOVERER_STREAM_INFO (get_audio_info (gst_info));
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (
+                        gst_info);
 
         if (!priv->caps)
                 priv->caps = gst_discoverer_stream_info_get_caps (info);
@@ -119,9 +130,11 @@ get_int_value (GUPnPDLNAGstAudioInformation *gst_info,
         GstCaps *caps = get_caps (gst_info);
         GstDiscovererStreamInfo *stream =
                          GST_DISCOVERER_STREAM_INFO (get_audio_info (gst_info));
-        GstDiscovererInfo *info = gst_info->priv->info;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (
+                        gst_info);
 
-        return gupnp_dlna_gst_get_int_value (caps, stream, info, name);
+        return gupnp_dlna_gst_get_int_value (caps, stream, priv->info, name);
 }
 
 static GUPnPDLNAStringValue
@@ -131,9 +144,11 @@ get_string_value (GUPnPDLNAGstAudioInformation *gst_info,
         GstCaps *caps = get_caps (gst_info);
         GstDiscovererStreamInfo *stream =
                          GST_DISCOVERER_STREAM_INFO (get_audio_info (gst_info));
-        GstDiscovererInfo *info = gst_info->priv->info;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (
+                        gst_info);
 
-        return gupnp_dlna_gst_get_string_value (caps, stream, info, name);
+        return gupnp_dlna_gst_get_string_value (caps, stream, priv->info, name);
 }
 
 static GUPnPDLNAIntValue
@@ -282,7 +297,8 @@ gupnp_dlna_gst_audio_information_dispose (GObject *object)
 {
         GUPnPDLNAGstAudioInformation *info =
                                       GUPNP_DLNA_GST_AUDIO_INFORMATION (object);
-        GUPnPDLNAGstAudioInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (info);
         GObjectClass *parent_class =
                  G_OBJECT_CLASS (gupnp_dlna_gst_audio_information_parent_class);
 
@@ -303,7 +319,8 @@ gupnp_dlna_gst_audio_information_set_property (GObject      *object,
 {
         GUPnPDLNAGstAudioInformation *info =
                                       GUPNP_DLNA_GST_AUDIO_INFORMATION (object);
-        GUPnPDLNAGstAudioInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -327,7 +344,8 @@ gupnp_dlna_gst_audio_information_get_property (GObject    *object,
 {
         GUPnPDLNAGstAudioInformation *info =
                                       GUPNP_DLNA_GST_AUDIO_INFORMATION (object);
-        GUPnPDLNAGstAudioInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstAudioInformationPrivate *priv =
+                gupnp_dlna_gst_audio_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -382,14 +400,6 @@ gupnp_dlna_gst_audio_information_class_init
 static void
 gupnp_dlna_gst_audio_information_init (GUPnPDLNAGstAudioInformation *self)
 {
-        GUPnPDLNAGstAudioInformationPrivate *priv =
-            gupnp_dlna_gst_audio_information_get_instance_private (self);
-
-        priv->info = NULL;
-        priv->stream_list = NULL;
-        priv->audio_info = NULL;
-        priv->caps = NULL;
-        self->priv = priv;
 }
 
 GUPnPDLNAGstAudioInformation *
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.h
index 4e8f8e1..d092314 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-audio-information.h
@@ -28,44 +28,29 @@
 
 G_BEGIN_DECLS
 
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstAudioInformation,
+                      gupnp_dlna_gst_audio_information,
+                      GUPNP_DLNA,
+                      GST_AUDIO_INFORMATION,
+                      GUPnPDLNAAudioInformation)
+
 #define GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION \
         (gupnp_dlna_gst_audio_information_get_type())
 
-#define GUPNP_DLNA_GST_AUDIO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION, \
-                                     GUPnPDLNAGstAudioInformation))
-
-#define GUPNP_DLNA_GST_AUDIO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION, \
-                                  GUPnPDLNAGstAudioInformationClass))
-
-#define GUPNP_IS_DLNA_GST_AUDIO_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION))
-
-#define GUPNP_IS_DLNA_GST_AUDIO_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION))
-
-#define GUPNP_DLNA_GST_AUDIO_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_AUDIO_INFORMATION, \
-                                    GUPnPDLNAGstAudioInformationClass))
-
-typedef struct _GUPnPDLNAGstAudioInformationPrivate
-                GUPnPDLNAGstAudioInformationPrivate;
-
-typedef struct {
-        GUPnPDLNAAudioInformation parent;
-
-        GUPnPDLNAGstAudioInformationPrivate *priv;
-} GUPnPDLNAGstAudioInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_GST_AUDIO_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_GST_AUDIO_INFORMATION GUPNP_DLNA_IS_GST_AUDIO_INFORMATION
+/**
+ * GUPNP_IS_DLNA_GST_AUDIO_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_GST_AUDIO_INFORMATION_CLASS                              \
+        GUPNP_DLNA_IS_GST_AUDIO_INFORMATION_CLASS
 
-typedef struct {
+struct _GUPnPDLNAGstAudioInformationClass {
         GUPnPDLNAAudioInformationClass parent_class;
-} GUPnPDLNAGstAudioInformationClass;
+};
 
 GType
 gupnp_dlna_gst_audio_information_get_type (void);
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.c
index 22faa26..f245836 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.c
@@ -30,6 +30,12 @@ struct _GUPnPDLNAGstContainerInformationPrivate {
         GstDiscovererStreamInfo *container_info;
         GstCaps *caps;
 };
+typedef struct _GUPnPDLNAGstContainerInformationPrivate
+        GUPnPDLNAGstContainerInformationPrivate;
+
+struct _GUPnPDLNAGstContainerInformation{
+        GUPnPDLNAContainerInformation parent;
+};
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstContainerInformation,
                             gupnp_dlna_gst_container_information,
@@ -45,7 +51,9 @@ enum
 static GstDiscovererStreamInfo *
 get_container_info (GUPnPDLNAGstContainerInformation *gst_info)
 {
-        GUPnPDLNAGstContainerInformationPrivate *priv = gst_info->priv;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        gst_info);
 
         if (!priv->container_info) {
                 priv->container_info =
@@ -58,7 +66,9 @@ get_container_info (GUPnPDLNAGstContainerInformation *gst_info)
 static GstCaps *
 get_caps (GUPnPDLNAGstContainerInformation *gst_info)
 {
-        GUPnPDLNAGstContainerInformationPrivate *priv = gst_info->priv;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        gst_info);
 
         if (!priv->caps) {
                 priv->caps = gst_discoverer_stream_info_get_caps
@@ -74,9 +84,11 @@ get_int_value (GUPnPDLNAGstContainerInformation *gst_info,
 {
         GstCaps *caps = get_caps (gst_info);
         GstDiscovererStreamInfo *stream = get_container_info (gst_info);
-        GstDiscovererInfo *info = gst_info->priv->info;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        gst_info);
 
-        return gupnp_dlna_gst_get_int_value (caps, stream, info, name);
+        return gupnp_dlna_gst_get_int_value (caps, stream, priv->info, name);
 }
 
 static GUPnPDLNAStringValue
@@ -85,9 +97,11 @@ get_string_value (GUPnPDLNAGstContainerInformation *gst_info,
 {
         GstCaps *caps = get_caps (gst_info);
         GstDiscovererStreamInfo *stream = get_container_info (gst_info);
-        GstDiscovererInfo *info = gst_info->priv->info;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        gst_info);
 
-        return gupnp_dlna_gst_get_string_value (caps, stream, info, name);
+        return gupnp_dlna_gst_get_string_value (caps, stream, priv->info, name);
 }
 
 static GUPnPDLNABoolValue
@@ -96,9 +110,11 @@ get_bool_value (GUPnPDLNAGstContainerInformation *gst_info,
 {
         GstCaps *caps = get_caps (gst_info);
         GstDiscovererStreamInfo *stream = get_container_info (gst_info);
-        GstDiscovererInfo *info = gst_info->priv->info;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        gst_info);
 
-        return gupnp_dlna_gst_get_bool_value (caps, stream, info, name);
+        return gupnp_dlna_gst_get_bool_value (caps, stream, priv->info, name);
 }
 
 static GUPnPDLNAIntValue
@@ -160,7 +176,9 @@ gupnp_dlna_gst_container_information_dispose (GObject *object)
 {
         GUPnPDLNAGstContainerInformation *info =
                                   GUPNP_DLNA_GST_CONTAINER_INFORMATION (object);
-        GUPnPDLNAGstContainerInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        info);
         GObjectClass *parent_class =
              G_OBJECT_CLASS (gupnp_dlna_gst_container_information_parent_class);
 
@@ -179,7 +197,9 @@ gupnp_dlna_gst_container_information_set_property (GObject      *object,
 {
         GUPnPDLNAGstContainerInformation *info =
                                   GUPNP_DLNA_GST_CONTAINER_INFORMATION (object);
-        GUPnPDLNAGstContainerInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -203,7 +223,9 @@ gupnp_dlna_gst_container_information_get_property (GObject    *object,
 {
         GUPnPDLNAGstContainerInformation *info =
                                   GUPNP_DLNA_GST_CONTAINER_INFORMATION (object);
-        GUPnPDLNAGstContainerInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstContainerInformationPrivate *priv =
+                gupnp_dlna_gst_container_information_get_instance_private (
+                        info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -253,8 +275,6 @@ static void
 gupnp_dlna_gst_container_information_init
                                         (GUPnPDLNAGstContainerInformation *self)
 {
-        self->priv = gupnp_dlna_gst_container_information_get_instance_private
-                                        (self);
 }
 
 GUPnPDLNAGstContainerInformation *
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.h
index c480ca6..2f827bb 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-container-information.h
@@ -28,45 +28,28 @@
 
 G_BEGIN_DECLS
 
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstContainerInformation,
+                      gupnp_dlna_gst_container_information,
+                      GUPNP_DLNA,
+                      GST_CONTAINER_INFORMATION,
+                      GUPnPDLNAContainerInformation)
+
 #define GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION \
         (gupnp_dlna_gst_container_information_get_type())
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_GST_DLNA_CONTAINER_INFORMATION: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_CONTAINER_INFORMATION GUPNP_DLNA_IS_GST_CONTAINER_INFORMATION
+/**
+ * GUPNP_IS_GST_DLNA_CONTAINER_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_CONTAINER_INFORMATION_CLASS                          \
+        GUPNP_DLNA_IS_GST_CONTAINER_INFORMATION_CLASS
 
-#define GUPNP_DLNA_GST_CONTAINER_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST \
-                                   ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION, \
-                                    GUPnPDLNAGstContainerInformation))
-
-#define GUPNP_DLNA_GST_CONTAINER_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION, \
-                                  GUPnPDLNAGstContainerInformationClass))
-
-#define GUPNP_IS_DLNA_GST_CONTAINER_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION))
-
-#define GUPNP_IS_DLNA_GST_CONTAINER_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION))
-
-#define GUPNP_DLNA_GST_CONTAINER_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_CONTAINER_INFORMATION, \
-                                    GUPnPDLNAGstContainerInformationClass))
-
-typedef struct _GUPnPDLNAGstContainerInformationPrivate
-                GUPnPDLNAGstContainerInformationPrivate;
-
-typedef struct {
-        GUPnPDLNAContainerInformation parent;
-
-        GUPnPDLNAGstContainerInformationPrivate *priv;
-} GUPnPDLNAGstContainerInformation;
-
-typedef struct {
+struct _GUPnPDLNAGstContainerInformationClass {
         GUPnPDLNAContainerInformationClass parent_class;
-} GUPnPDLNAGstContainerInformationClass;
+};
 
 GType
 gupnp_dlna_gst_container_information_get_type (void);
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.c
index e594fff..733e7c1 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.c
@@ -31,6 +31,12 @@ struct _GUPnPDLNAGstImageInformationPrivate {
         GstDiscovererVideoInfo *image_info;
         GstCaps *caps;
 };
+typedef struct _GUPnPDLNAGstImageInformationPrivate
+        GUPnPDLNAGstImageInformationPrivate;
+
+struct _GUPnPDLNAGstImageInformation {
+        GUPnPDLNAImageInformation parent;
+};
 
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstImageInformation,
                             gupnp_dlna_gst_image_information,
@@ -46,7 +52,9 @@ enum
 static GstDiscovererVideoInfo *
 get_image_info (GUPnPDLNAGstImageInformation *gst_info)
 {
-        GUPnPDLNAGstImageInformationPrivate *priv = gst_info->priv;
+        GUPnPDLNAGstImageInformationPrivate *priv =
+                gupnp_dlna_gst_image_information_get_instance_private (
+                        gst_info);
 
         if (!priv->image_info) {
                 GList *iter;
@@ -78,7 +86,9 @@ get_image_info (GUPnPDLNAGstImageInformation *gst_info)
 static GstCaps *
 get_caps (GUPnPDLNAGstImageInformation *gst_info)
 {
-        GUPnPDLNAGstImageInformationPrivate *priv = gst_info->priv;
+        GUPnPDLNAGstImageInformationPrivate *priv =
+                gupnp_dlna_gst_image_information_get_instance_private (
+                        gst_info);
 
         if (!priv->caps)
                 priv->caps = gst_discoverer_stream_info_get_caps
@@ -153,7 +163,8 @@ gupnp_dlna_gst_image_information_dispose (GObject *object)
 {
         GUPnPDLNAGstImageInformation *info =
                                       GUPNP_DLNA_GST_IMAGE_INFORMATION (object);
-        GUPnPDLNAGstImageInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstImageInformationPrivate *priv =
+                gupnp_dlna_gst_image_information_get_instance_private (info);
         GObjectClass *parent_class =
                  G_OBJECT_CLASS (gupnp_dlna_gst_image_information_parent_class);
         g_clear_pointer (&priv->info, gupnp_dlna_gst_discoverer_info_unref);
@@ -173,7 +184,8 @@ gupnp_dlna_gst_image_information_set_property (GObject      *object,
 {
         GUPnPDLNAGstImageInformation *info =
                                       GUPNP_DLNA_GST_IMAGE_INFORMATION (object);
-        GUPnPDLNAGstImageInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstImageInformationPrivate *priv =
+                gupnp_dlna_gst_image_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -197,7 +209,8 @@ gupnp_dlna_gst_image_information_get_property (GObject    *object,
 {
         GUPnPDLNAGstImageInformation *info =
                                       GUPNP_DLNA_GST_IMAGE_INFORMATION (object);
-        GUPnPDLNAGstImageInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstImageInformationPrivate *priv =
+                gupnp_dlna_gst_image_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -244,7 +257,6 @@ gupnp_dlna_gst_image_information_class_init
 static void
 gupnp_dlna_gst_image_information_init (GUPnPDLNAGstImageInformation *self)
 {
-        self->priv = gupnp_dlna_gst_image_information_get_instance_private (self);
 }
 
 GUPnPDLNAGstImageInformation *
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.h
index 457ea61..2d4caa9 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-image-information.h
@@ -31,44 +31,26 @@ G_BEGIN_DECLS
 #define GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION \
         (gupnp_dlna_gst_image_information_get_type())
 
-#define GUPNP_DLNA_GST_IMAGE_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION, \
-                                     GUPnPDLNAGstImageInformation))
-
-#define GUPNP_DLNA_GST_IMAGE_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION, \
-                                  GUPnPDLNAGstImageInformationClass))
-
-#define GUPNP_IS_DLNA_GST_IMAGE_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION))
-
-#define GUPNP_IS_DLNA_GST_IMAGE_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION))
-
-#define GUPNP_DLNA_GST_IMAGE_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_IMAGE_INFORMATION, \
-                                    GUPnPDLNAGstImageInformationClass))
-
-typedef struct _GUPnPDLNAGstImageInformationPrivate
-                GUPnPDLNAGstImageInformationPrivate;
-
-typedef struct {
-        GUPnPDLNAImageInformation parent;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_GST_DLNA_IMAGE_INFORMATION: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_IMAGE_INFORMATION GUPNP_DLNA_IS_IMAGE_INFORMATION
+/**
+ * GUPNP_IS_GST_DLNA_IMAGE_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_IMAGE_INFORMATION_CLASS                              \
+        GUPNP_DLNA_IS_IMAGE_INFORMATION_CLASS
 
-        GUPnPDLNAGstImageInformationPrivate *priv;
-} GUPnPDLNAGstImageInformation;
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstImageInformation,
+                      gupnp_dlna_gst_image_information,
+                      GUPNP_DLNA,
+                      GST_IMAGE_INFORMATION,
+                      GUPnPDLNAImageInformation)
 
-typedef struct {
+struct _GUPnPDLNAGstImageInformationClass {
         GUPnPDLNAImageInformationClass parent_class;
-} GUPnPDLNAGstImageInformationClass;
-
-GType
-gupnp_dlna_gst_image_information_get_type (void);
+};
 
 GUPnPDLNAGstImageInformation *
 gupnp_dlna_gst_image_information_new_from_discoverer_info
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.c
index 08f1efa..205f8d0 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.c
@@ -33,6 +33,12 @@ struct _GUPnPDLNAGstInformationPrivate {
         GstDiscovererInfo* info;
 };
 
+typedef struct _GUPnPDLNAGstInformationPrivate GUPnPDLNAGstInformationPrivate;
+
+struct _GUPnPDLNAGstInformation {
+        GUPnPDLNAInformation parent;
+};
+
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstInformation,
                             gupnp_dlna_gst_information,
                             GUPNP_TYPE_DLNA_INFORMATION)
@@ -47,7 +53,8 @@ static void
 gupnp_dlna_gst_information_dispose (GObject *object)
 {
         GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (object);
-        GUPnPDLNAGstInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
 
         g_clear_pointer (&priv->info, gupnp_dlna_gst_discoverer_info_unref);
         G_OBJECT_CLASS
@@ -61,7 +68,8 @@ gupnp_dlna_gst_information_set_property (GObject      *object,
                                          GParamSpec   *pspec)
 {
         GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (object);
-        GUPnPDLNAGstInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -86,7 +94,8 @@ gupnp_dlna_gst_information_get_property (GObject    *object,
                                          GParamSpec *pspec)
 {
         GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (object);
-        GUPnPDLNAGstInformationPrivate *priv = info->priv;
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
 
         switch (property_id) {
         case PROP_INFO:
@@ -104,47 +113,56 @@ gupnp_dlna_gst_information_get_property (GObject    *object,
 GUPnPDLNAAudioInformation *
 backend_get_audio_information (GUPnPDLNAInformation *self)
 {
-        GUPnPDLNAGstInformation *gst_info = GUPNP_DLNA_GST_INFORMATION (self);
-
-        if (gst_info == NULL)
+        if (!GUPNP_DLNA_IS_GST_INFORMATION (self))
                 return NULL;
 
-        return GUPNP_DLNA_AUDIO_INFORMATION
-                (gupnp_dlna_gst_audio_information_new_from_discoverer_info
-                                        (gst_info->priv->info));
+        GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (self);
+
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
+
+        return GUPNP_DLNA_AUDIO_INFORMATION (
+                gupnp_dlna_gst_audio_information_new_from_discoverer_info (
+                        priv->info));
 }
 
 GUPnPDLNAContainerInformation *
 backend_get_container_information (GUPnPDLNAInformation *self)
 {
-        GUPnPDLNAGstInformation *gst_info = GUPNP_DLNA_GST_INFORMATION (self);
-
-        if (gst_info == NULL)
+        if (!GUPNP_DLNA_IS_GST_INFORMATION (self))
                 return NULL;
 
+        GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (self);
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
+
         return GUPNP_DLNA_CONTAINER_INFORMATION
                 (gupnp_dlna_gst_container_information_new_from_discoverer_info
-                                        (gst_info->priv->info));
+                                        (priv->info));
 }
 
 GUPnPDLNAImageInformation *
 backend_get_image_information (GUPnPDLNAInformation *self)
 {
-        GUPnPDLNAGstInformation *gst_info = GUPNP_DLNA_GST_INFORMATION (self);
+        GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (self);
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
 
-        return GUPNP_DLNA_IMAGE_INFORMATION
-                (gupnp_dlna_gst_image_information_new_from_discoverer_info
-                                        (gst_info->priv->info));
+        return GUPNP_DLNA_IMAGE_INFORMATION (
+                gupnp_dlna_gst_image_information_new_from_discoverer_info (
+                        priv->info));
 }
 
 GUPnPDLNAVideoInformation *
 backend_get_video_information (GUPnPDLNAInformation *self)
 {
-        GUPnPDLNAGstInformation *gst_info = GUPNP_DLNA_GST_INFORMATION (self);
+        GUPnPDLNAGstInformation *info = GUPNP_DLNA_GST_INFORMATION (self);
+        GUPnPDLNAGstInformationPrivate *priv =
+                gupnp_dlna_gst_information_get_instance_private (info);
 
-        return GUPNP_DLNA_VIDEO_INFORMATION
-                (gupnp_dlna_gst_video_information_new_from_discoverer_info
-                                        (gst_info->priv->info));
+        return GUPNP_DLNA_VIDEO_INFORMATION (
+                gupnp_dlna_gst_video_information_new_from_discoverer_info (
+                        priv->info));
 }
 
 static void
@@ -179,7 +197,6 @@ gupnp_dlna_gst_information_class_init
 static void
 gupnp_dlna_gst_information_init (GUPnPDLNAGstInformation *self)
 {
-        self->priv = gupnp_dlna_gst_information_get_instance_private (self);
 }
 
 GUPnPDLNAGstInformation *
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.h
index fb17b44..c051257 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-information.h
@@ -30,45 +30,26 @@
 
 G_BEGIN_DECLS
 
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstInformation,
+                      gupnp_dlna_gst_information,
+                      GUPNP_DLNA,
+                      GST_INFORMATION,
+                      GUPnPDLNAInformation)
 #define GUPNP_TYPE_DLNA_GST_INFORMATION (gupnp_dlna_gst_information_get_type())
 
-#define GUPNP_DLNA_GST_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_INFORMATION, \
-                                     GUPnPDLNAGstInformation))
-
-#define GUPNP_DLNA_GST_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_INFORMATION, \
-                                  GUPnPDLNAGstInformationClass))
-
-#define GUPNP_IS_DLNA_GST_INFORMATION(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_INFORMATION))
-
-#define GUPNP_IS_DLNA_GST_INFORMATION_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_INFORMATION))
-
-#define GUPNP_DLNA_GST_INFORMATION_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_INFORMATION, \
-                                    GUPnPDLNAGstInformationClass))
-
-typedef struct _GUPnPDLNAGstInformationPrivate GUPnPDLNAGstInformationPrivate;
-
-typedef struct {
-        GUPnPDLNAInformation parent;
-
-        GUPnPDLNAGstInformationPrivate *priv;
-} GUPnPDLNAGstInformation;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_GST_DLNA_INFORMATION: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_INFORMATION GUPNP_DLNA_IS_GST_IMAGE_INFORMATION
+/**
+ * GUPNP_IS_GST_DLNA_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_INFORMATION_CLASS GUPNP_DLNA_IS_GST_IMAGE_INFORMATION_CLASS
 
-typedef struct {
+struct _GUPnPDLNAGstInformationClass {
         GUPnPDLNAInformationClass parent_class;
-} GUPnPDLNAGstInformationClass;
-
-GType
-gupnp_dlna_gst_information_get_type (void);
+};
 
 GUPnPDLNAGstInformation *
 gupnp_dlna_gst_information_new_from_discoverer_info (const gchar       *uri,
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.c
index 702d634..9c4d4f9 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.c
@@ -26,19 +26,37 @@
 #include "gupnp-dlna-gst-information.h"
 #include "gupnp-dlna-gst-utils.h"
 
-struct _GUPnPDLNAGstMetadataExtractorPrivate {
-        gpointer placeholder;
+typedef struct _GUPnPDLNAGstMetadataExtractorPrivate
+        GUPnPDLNAGstMetadataExtractorPrivate;
+
+/**
+ * GUPnPDLNAGstMetadataExtractor:
+ *
+ * The top-level object used to for metadata extraction.
+ */
+struct _GUPnPDLNAGstMetadataExtractor {
+        GUPnPDLNAMetadataExtractor parent;
+
+        GUPnPDLNAGstMetadataExtractorPrivate *priv;
 };
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_GST_METADATA_BACKEND: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_METADATA_BACKEND GUPNP_DLNA_IS_GST_METADATA_BACKEND
+/**
+ * GUPNP_IS_GST_DLNA_METADATA_BACKEND_CLASS: (skip)
+ */
+#define GUPNP_IS_GST_DLNA_METADATA_BACKEND_CLASS GUPNP_DLNA_IS_GST_METADATA_BACKEND_CLASS
 
-G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstMetadataExtractor,
-                            gupnp_dlna_gst_metadata_extractor,
-                            GUPNP_TYPE_DLNA_METADATA_EXTRACTOR)
+G_DEFINE_TYPE (GUPnPDLNAGstMetadataExtractor,
+               gupnp_dlna_gst_metadata_extractor,
+               GUPNP_TYPE_DLNA_METADATA_EXTRACTOR)
 
 static gboolean
 unref_discoverer_in_idle (GstDiscoverer *discoverer)
 {
-        if (discoverer)
-                g_object_unref (discoverer);
+        g_clear_object (&discoverer);
 
         return FALSE;
 }
@@ -142,7 +160,6 @@ gupnp_dlna_gst_metadata_extractor_class_init
 static void
 gupnp_dlna_gst_metadata_extractor_init (GUPnPDLNAGstMetadataExtractor *self)
 {
-        self->priv = gupnp_dlna_gst_metadata_extractor_get_instance_private (self);
 }
 
 GUPnPDLNAGstMetadataExtractor *
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.h
index f1bd6ca..dcef839 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-metadata-extractor.h
@@ -33,49 +33,16 @@ G_BEGIN_DECLS
 #define GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR \
         (gupnp_dlna_gst_metadata_extractor_get_type())
 
-#define GUPNP_DLNA_GST_METADATA_EXTRACTOR(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR, \
-                                     GUPnPDLNAGstMetadataExtractor))
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstMetadataExtractor,
+                      gupnp_dlna_gst_metadata_extractor,
+                      GUPNP_DLNA,
+                      GST_METADATA_EXTRACTOR,
+                      GUPnPDLNAMetadataExtractor)
 
-#define GUPNP_DLNA_GST_METADATA_EXTRACTOR_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR, \
-                                  GUPnPDLNAGstMetadataExtractorClass))
 
-#define GUPNP_IS_DLNA_GST_METADATA_EXTRACTOR(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR))
-
-#define GUPNP_IS_DLNA_GST_METADATA_EXTRACTOR_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR))
-
-#define GUPNP_DLNA_GST_METADATA_EXTRACTOR_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_GST_METADATA_EXTRACTOR, \
-                                    GUPnPDLNAGstMetadataExtractorClass))
-
-typedef struct _GUPnPDLNAGstMetadataExtractorPrivate
-                GUPnPDLNAGstMetadataExtractorPrivate;
-
-/**
- * GUPnPDLNAGstMetadataExtractor:
- *
- * The top-level object used to for metadata extraction.
- */
-typedef struct {
-        GUPnPDLNAMetadataExtractor parent;
-
-        GUPnPDLNAGstMetadataExtractorPrivate *priv;
-} GUPnPDLNAGstMetadataExtractor;
-
-typedef struct {
+struct _GUPnPDLNAGstMetadataExtractorClass {
         GUPnPDLNAMetadataExtractorClass parent_class;
-} GUPnPDLNAGstMetadataExtractorClass;
-
-GType
-gupnp_dlna_gst_metadata_extractor_get_type (void);
+};
 
 GUPnPDLNAGstMetadataExtractor *
 gupnp_dlna_gst_metadata_extractor_new (void);
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.c b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.c
index aee6a36..f35c1e1 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.c
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.c
@@ -32,6 +32,14 @@ struct _GUPnPDLNAGstVideoInformationPrivate {
         GstCaps *caps;
 };
 
+typedef struct _GUPnPDLNAGstVideoInformationPrivate GUPnPDLNAGstVideoInformationPrivate;
+
+struct _GUPnPDLNAGstVideoInformation {
+        GUPnPDLNAVideoInformation parent;
+
+        GUPnPDLNAGstVideoInformationPrivate *priv;
+};
+
 G_DEFINE_TYPE_WITH_PRIVATE (GUPnPDLNAGstVideoInformation,
                             gupnp_dlna_gst_video_information,
                             GUPNP_TYPE_DLNA_VIDEO_INFORMATION)
diff --git a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.h b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.h
index 93ebbce..ecb2b9b 100644
--- a/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.h
+++ b/libgupnp-dlna/metadata-backends/gstreamer/gupnp-dlna-gst-video-information.h
@@ -30,40 +30,25 @@ G_BEGIN_DECLS
 
 #define GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION gupnp_dlna_gst_video_information_get_type()
 
-#define GUPNP_DLNA_GST_VIDEO_INFORMATION(obj)                                     \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj),                             \
-                                     GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION,       \
-                                     GUPnPDLNAGstVideoInformation))
-
-#define GUPNP_DLNA_GST_VIDEO_INFORMATION_CLASS(klass)                             \
-        (G_TYPE_CHECK_CLASS_CAST ((klass),                              \
-                                  GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION,          \
-                                  GUPnPDLNAGstVideoInformationClass))
-
-#define GUPNP_IS_DLNA_GST_VIDEO_INFORMATION(obj)                                  \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION))
-
-#define GUPNP_IS_DLNA_GST_VIDEO_INFORMATION_CLASS(klass)                          \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION))
-
-#define GUPNP_DLNA_GST_VIDEO_INFORMATION_GET_CLASS(obj)                           \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj),                              \
-                                    GUPNP_TYPE_DLNA_GST_VIDEO_INFORMATION,        \
-                                    GUPnPDLNAGstVideoInformationClass))
-
-typedef struct _GUPnPDLNAGstVideoInformationPrivate GUPnPDLNAGstVideoInformationPrivate;
-
-typedef struct {
-        GUPnPDLNAVideoInformation parent;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_VIDEO_INFORMATION: (skip)
+ */
+#define GUPNP_IS_DLNA_GST_VIDEO_INFORMATION GUPNP_DLNA_IS_GST_VIDEO_INFORMATION
+/**
+ * GUPNP_IS_DLNA_VIDEO_INFORMATION_CLASS: (skip)
+ */
+#define GUPNP_IS_DLNA_GST_VIDEO_INFORMATION_CLASS GUPNP_DLNA_IS_GST_VIDEO_INFORMATION_CLASS
 
-        GUPnPDLNAGstVideoInformationPrivate *priv;
-} GUPnPDLNAGstVideoInformation;
+G_DECLARE_FINAL_TYPE (GUPnPDLNAGstVideoInformation,
+                      gupnp_dlna_gst_video_information,
+                      GUPNP_DLNA,
+                      GST_VIDEO_INFORMATION,
+                      GUPnPDLNAVideoInformation)
 
-typedef struct {
+struct _GUPnPDLNAGstVideoInformationClass {
         GUPnPDLNAVideoInformationClass parent_class;
-} GUPnPDLNAGstVideoInformationClass;
-
-GType gupnp_dlna_gst_video_information_get_type (void);
+};
 
 GUPnPDLNAGstVideoInformation *
 gupnp_dlna_gst_video_information_new_from_discoverer_info (GstDiscovererInfo *info);
diff --git a/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.c b/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.c
index 766a739..d78c75d 100644
--- a/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.c
+++ b/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.c
@@ -69,6 +69,9 @@ struct _GUPnPDLNAMetadataExtractorPrivate {
         gpointer placeholder;
 };
 
+typedef struct _GUPnPDLNAMetadataExtractorPrivate
+        GUPnPDLNAMetadataExtractorPrivate;
+
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GUPnPDLNAMetadataExtractor,
                                      gupnp_dlna_metadata_extractor,
                                      G_TYPE_OBJECT)
@@ -107,10 +110,6 @@ gupnp_dlna_metadata_extractor_class_init
 static void
 gupnp_dlna_metadata_extractor_init (GUPnPDLNAMetadataExtractor *self)
 {
-        GUPnPDLNAMetadataExtractorPrivate *priv =
-            gupnp_dlna_metadata_extractor_get_instance_private (self);
-
-        self->priv = priv;
 }
 
 /**
@@ -134,13 +133,13 @@ gupnp_dlna_metadata_extractor_extract_async
 {
         GUPnPDLNAMetadataExtractorClass *extractor_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_METADATA_EXTRACTOR (extractor),
+        g_return_val_if_fail (GUPNP_DLNA_IS_METADATA_EXTRACTOR (extractor),
                               FALSE);
         g_return_val_if_fail (uri != NULL, FALSE);
 
         extractor_class = GUPNP_DLNA_METADATA_EXTRACTOR_GET_CLASS (extractor);
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_METADATA_EXTRACTOR_CLASS
+        g_return_val_if_fail (GUPNP_DLNA_IS_METADATA_EXTRACTOR_CLASS
                                         (extractor_class),
                               FALSE);
         g_return_val_if_fail (extractor_class->extract_async != NULL, FALSE);
@@ -172,13 +171,13 @@ gupnp_dlna_metadata_extractor_extract_sync
 {
         GUPnPDLNAMetadataExtractorClass *extractor_class;
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_METADATA_EXTRACTOR (extractor),
+        g_return_val_if_fail (GUPNP_DLNA_IS_METADATA_EXTRACTOR (extractor),
                               NULL);
         g_return_val_if_fail (uri != NULL, NULL);
 
         extractor_class = GUPNP_DLNA_METADATA_EXTRACTOR_GET_CLASS (extractor);
 
-        g_return_val_if_fail (GUPNP_IS_DLNA_METADATA_EXTRACTOR_CLASS
+        g_return_val_if_fail (GUPNP_DLNA_IS_METADATA_EXTRACTOR_CLASS
                                         (extractor_class),
                               NULL);
         g_return_val_if_fail (extractor_class->extract_async != NULL, NULL);
@@ -206,8 +205,8 @@ gupnp_dlna_metadata_extractor_emit_done (GUPnPDLNAMetadataExtractor *extractor,
                                          GUPnPDLNAInformation       *info,
                                          GError                     *error)
 {
-        g_return_if_fail (GUPNP_IS_DLNA_METADATA_EXTRACTOR (extractor));
-        g_return_if_fail (GUPNP_IS_DLNA_INFORMATION (info));
+        g_return_if_fail (GUPNP_DLNA_IS_METADATA_EXTRACTOR (extractor));
+        g_return_if_fail (GUPNP_DLNA_IS_INFORMATION (info));
 
         g_signal_emit (extractor, signals[DONE], 0, info, error);
 }
diff --git a/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.h b/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.h
index 610d28d..79f294f 100644
--- a/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.h
+++ b/libgupnp-dlna/metadata/gupnp-dlna-metadata-extractor.h
@@ -29,45 +29,26 @@
 
 G_BEGIN_DECLS
 
+G_DECLARE_DERIVABLE_TYPE (GUPnPDLNAMetadataExtractor,
+                          gupnp_dlna_metadata_extractor,
+                          GUPNP_DLNA,
+                          METADATA_EXTRACTOR,
+                          GObject)
+
 #define GUPNP_TYPE_DLNA_METADATA_EXTRACTOR \
         (gupnp_dlna_metadata_extractor_get_type())
 
-#define GUPNP_DLNA_METADATA_EXTRACTOR(obj) \
-        (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
-                                     GUPNP_TYPE_DLNA_METADATA_EXTRACTOR, \
-                                     GUPnPDLNAMetadataExtractor))
-
-#define GUPNP_DLNA_METADATA_EXTRACTOR_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_CAST ((klass), \
-                                  GUPNP_TYPE_DLNA_METADATA_EXTRACTOR, \
-                                  GUPnPDLNAMetadataExtractorClass))
-
-#define GUPNP_IS_DLNA_METADATA_EXTRACTOR(obj) \
-        (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
-                                     GUPNP_TYPE_DLNA_METADATA_EXTRACTOR))
-
-#define GUPNP_IS_DLNA_METADATA_EXTRACTOR_CLASS(klass) \
-        (G_TYPE_CHECK_CLASS_TYPE ((klass), \
-                                  GUPNP_TYPE_DLNA_METADATA_EXTRACTOR))
-
-#define GUPNP_DLNA_METADATA_EXTRACTOR_GET_CLASS(obj) \
-        (G_TYPE_INSTANCE_GET_CLASS ((obj), \
-                                    GUPNP_TYPE_DLNA_METADATA_EXTRACTOR, \
-                                    GUPnPDLNAMetadataExtractorClass))
-
-typedef struct _GUPnPDLNAMetadataExtractorPrivate
-                GUPnPDLNAMetadataExtractorPrivate;
+// Backwards-compatible defines
+/**
+ * GUPNP_IS_DLNA_METADATA_EXTRACTOR: (skip)
+ */
+#define GUPNP_IS_DLNA_METADATA_EXTRACTOR GUPNP_DLNA_IS_METADATA_EXTRACTOR
 
 /**
- * GUPnPDLNAMetadataExtractor:
- *
- * The top-level object used to for metadata extraction.
+ * GUPNP_IS_DLNA_METADATA_EXTRACTOR_CLASS: (skip)
  */
-typedef struct {
-        GObject parent;
+#define GUPNP_IS_DLNA_METADATA_EXTRACTOR_CLASS GUPNP_DLNA_IS_METADATA_EXTRACTOR_CLASS
 
-        GUPnPDLNAMetadataExtractorPrivate *priv;
-} GUPnPDLNAMetadataExtractor;
 
 /**
  * GUPnPDLNAMetadataExtractorClass:
@@ -78,7 +59,7 @@ typedef struct {
  * information about media file synchronously.
  * @_reserved: Padding. Ignore it.
  */
-typedef struct {
+struct _GUPnPDLNAMetadataExtractorClass {
         GObjectClass parent_class;
 
         /* virtuals */
@@ -95,10 +76,7 @@ typedef struct {
                           GError                     **error);
 
         gpointer _reserved[12];
-} GUPnPDLNAMetadataExtractorClass;
-
-GType
-gupnp_dlna_metadata_extractor_get_type (void);
+};
 
 gboolean
 gupnp_dlna_metadata_extractor_extract_async
diff --git a/meson.build b/meson.build
index 1d2f3b1..afbca02 100644
--- a/meson.build
+++ b/meson.build
@@ -9,7 +9,7 @@ gnome = import('gnome')
 
 shareddir = join_paths(get_option('prefix'), get_option('datadir'), 'gupnp-dlna-2.0')
 metadata_backend_dir = join_paths(get_option('prefix'), get_option('libdir'), 'gupnp-dlna')
-library_version = '3.0.0'
+library_version = '4.0.0'
 
 config = configuration_data()
 config.set_quoted('GUPNP_DLNA_DEFAULT_METADATA_BACKEND', get_option('default_backend'))