docs: specify possibility of a NULL return

[platform/upstream/gstreamer.git] / subprojects / gstreamer / gst / gstbuffer.h

diff --git a/subprojects/gstreamer/gst/gstbuffer.h b/subprojects/gstreamer/gst/gstbuffer.h
index 3de019c..6a8b84f 100644 (file)
--- a/subprojects/gstreamer/gst/gstbuffer.h
+++ b/subprojects/gstreamer/gst/gstbuffer.h
@@ -567,8 +567,8 @@ gboolean        gst_buffer_copy_into            (GstBuffer *dest, GstBuffer *src
  * that it returns. Don't access the argument after calling this function unless
  * you have an additional reference to it.
  *
- * Returns: (transfer full): a writable buffer which may or may not be the
- *     same as @buf
+ * Returns: (transfer full) (nullable): a writable buffer (which may or may not be the
+ *     same as @buf) or %NULL if copying is required but not possible.
  */
 #define         gst_buffer_make_writable(buf)   GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (buf)))
 
@@ -813,6 +813,11 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBufferPool, gst_object_unref)
  * }
  * ```
  *
+ * #GstMapInfo cannot be used with g_auto() because it is ambiguous whether it
+ * needs to be unmapped using gst_buffer_unmap() or gst_memory_unmap().
+ *
+ * See also #GstMemoryMapInfo.
+ *
  * Since: 1.22
  */
 typedef GstMapInfo GstBufferMapInfo;