meta: add return vale to transform

Add a boolean return value so that we can see when a transform fails.

gst/gstmeta.h

@@ -148,10 +148,12 @@ typedef struct {
  * Implementations should check the @type of the transform and parse
  * additional type specific fields in @data that should be used to update
  * the metadata on @transbuf.
+ *
+ * Returns: %TRUE if the transform could be performed
  */
-typedef void (*GstMetaTransformFunction) (GstBuffer *transbuf,
-                                          GstMeta *meta, GstBuffer *buffer,
-                                          GQuark type, gpointer data);
+typedef gboolean (*GstMetaTransformFunction) (GstBuffer *transbuf,
+                                              GstMeta *meta, GstBuffer *buffer,
+                                              GQuark type, gpointer data);
 
 /**
  * GstMetaInfo:

libs/gst/net/gstnetaddressmeta.c

@@ -33,28 +33,35 @@
 #include "gstnetaddressmeta.h"
 
 static gboolean
-net_address_meta_init (GstNetAddressMeta * meta, gpointer params,
-    GstBuffer * buffer)
+net_address_meta_init (GstMeta * meta, gpointer params, GstBuffer * buffer)
 {
-  meta->addr = NULL;
+  GstNetAddressMeta *nmeta = (GstNetAddressMeta *) meta;
+
+  nmeta->addr = NULL;
 
   return TRUE;
 }
 
-static void
-net_address_meta_transform (GstBuffer * transbuf, GstNetAddressMeta * meta,
+static gboolean
+net_address_meta_transform (GstBuffer * transbuf, GstMeta * meta,
     GstBuffer * buffer, GQuark type, gpointer data)
 {
+  GstNetAddressMeta *nmeta = (GstNetAddressMeta *) meta;
+
   /* we always copy no matter what transform */
-  gst_buffer_add_net_address_meta (transbuf, meta->addr);
+  gst_buffer_add_net_address_meta (transbuf, nmeta->addr);
+
+  return TRUE;
 }
 
 static void
-net_address_meta_free (GstNetAddressMeta * meta, GstBuffer * buffer)
+net_address_meta_free (GstMeta * meta, GstBuffer * buffer)
 {
-  if (meta->addr)
-    g_object_unref (meta->addr);
-  meta->addr = NULL;
+  GstNetAddressMeta *nmeta = (GstNetAddressMeta *) meta;
+
+  if (nmeta->addr)
+    g_object_unref (nmeta->addr);
+  nmeta->addr = NULL;
 }
 
 const GstMetaInfo *
@@ -66,9 +73,8 @@ gst_net_address_meta_get_info (void)
   if (meta_info == NULL) {
     meta_info = gst_meta_register ("GstNetAddressMeta", "GstNetAddressMeta",
         sizeof (GstNetAddressMeta),
-        (GstMetaInitFunction) net_address_meta_init,
-        (GstMetaFreeFunction) net_address_meta_free,
-        (GstMetaTransformFunction) net_address_meta_transform, tags);
+        net_address_meta_init,
+        net_address_meta_free, net_address_meta_transform, tags);
   }
   return meta_info;
 }

tests/check/gst/gstmeta.c

@@ -63,27 +63,28 @@ gst_meta_test_init (GstMetaTest * meta)
 }
 #endif
 
-static void
-test_init_func (GstMetaTest * meta, GstBuffer * buffer)
+static gboolean
+test_init_func (GstMeta * meta, gpointer params, GstBuffer * buffer)
 {
   GST_DEBUG ("init called on buffer %p, meta %p", buffer, meta);
   /* nothing to init really, the init function is mostly for allocating
    * additional memory or doing special setup as part of adding the metadata to
    * the buffer*/
+  return TRUE;
 }
 
 static void
-test_free_func (GstMetaTest * meta, GstBuffer * buffer)
+test_free_func (GstMeta * meta, GstBuffer * buffer)
 {
   GST_DEBUG ("free called on buffer %p, meta %p", buffer, meta);
   /* nothing to free really */
 }
 
-static void
-test_transform_func (GstBuffer * transbuf, GstMetaTest * meta,
+static gboolean
+test_transform_func (GstBuffer * transbuf, GstMeta * meta,
     GstBuffer * buffer, GQuark type, gpointer data)
 {
-  GstMetaTest *test;
+  GstMetaTest *test, *tmeta = (GstMetaTest *) meta;
 
   GST_DEBUG ("transform %s called from buffer %p to %p, meta %p",
       g_quark_to_string (type), buffer, transbuf, meta);
@@ -94,11 +95,11 @@ test_transform_func (GstBuffer * transbuf, GstMetaTest * meta,
     test = GST_META_TEST_ADD (transbuf);
     if (copy_data->offset == 0) {
       /* same offset, copy timestamps */
-      test->pts = meta->pts;
-      test->dts = meta->dts;
+      test->pts = tmeta->pts;
+      test->dts = tmeta->dts;
       if (copy_data->size == gst_buffer_get_size (buffer)) {
         /* same size, copy duration */
-        test->duration = meta->duration;
+        test->duration = tmeta->duration;
       } else {
         /* else clear */
         test->duration = GST_CLOCK_TIME_NONE;
@@ -108,8 +109,9 @@ test_transform_func (GstBuffer * transbuf, GstMetaTest * meta,
       test->dts = -1;
       test->duration = -1;
     }
-    test->clock_rate = meta->clock_rate;
+    test->clock_rate = tmeta->clock_rate;
   }
+  return TRUE;
 }
 
 static const GstMetaInfo *
@@ -121,9 +123,7 @@ gst_meta_test_get_info (void)
   if (meta_test_info == NULL) {
     meta_test_info = gst_meta_register ("GstMetaTest", "GstMetaTest",
         sizeof (GstMetaTest),
-        (GstMetaInitFunction) test_init_func,
-        (GstMetaFreeFunction) test_free_func,
-        (GstMetaTransformFunction) test_transform_func, tags);
+        test_init_func, test_free_func, test_transform_func, tags);
   }
   return meta_test_info;
 }