gstanalytics: Add transform function to copy the tensor meta

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8825>

subprojects/gst-plugins-bad/gst-libs/gst/analytics/gsttensormeta.c

@@ -22,6 +22,33 @@
 
 #include "gsttensormeta.h"
 
+static gboolean
+gst_tensor_meta_transform (GstBuffer * dest, GstMeta * meta,
+    GstBuffer * buffer, GQuark type, gpointer data)
+{
+  GstTensorMeta *dmeta, *smeta;
+
+  smeta = (GstTensorMeta *) meta;
+
+  if (GST_META_TRANSFORM_IS_COPY (type)) {
+    smeta = (GstTensorMeta *) meta;
+    dmeta = gst_buffer_add_tensor_meta (dest);
+    if (!dmeta)
+      return FALSE;
+    GST_TRACE ("copy tensor metadata");
+    dmeta->num_tensors = smeta->num_tensors;
+    dmeta->tensors = g_new (GstTensor *, smeta->num_tensors);
+    for (int i = 0; i < smeta->num_tensors; i++) {
+      dmeta->tensors[i] = gst_tensor_copy (smeta->tensors[i]);
+    }
+  } else {
+    GST_WARNING ("gst_tensor_meta_transform: transform type %u not supported",
+        type);
+    return FALSE;
+  }
+  return TRUE;
+}
+
 static gboolean
 gst_tensor_meta_init (GstMeta * meta, gpointer params, GstBuffer * buffer)
 {
@@ -80,7 +107,7 @@ gst_tensor_meta_get_info (void)
         sizeof (GstTensorMeta),
         gst_tensor_meta_init,
         gst_tensor_meta_free,
-        NULL);                  /* tensor_meta_transform not implemented */
+        gst_tensor_meta_transform);
     g_once_init_leave (&tmeta_info, meta);
   }
   return tmeta_info;

subprojects/gstreamer/gst/gstbuffer.c

@@ -718,6 +718,10 @@ gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
               "failed to copy meta %p of API type %s", meta,
               g_type_name (info->api));
         }
+      } else {
+        GST_CAT_WARNING (GST_CAT_BUFFER,
+            "No transform function for meta %p of API type %s\n", (void *) meta,
+            g_type_name (info->api));
       }
     }
   }