The return value is a list of GstElementFactory's that when
gst_element_factory_create()ed will create a GstRTPHeaderExtension.
Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/issues/897
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1136>
/**
* gst_rtp_get_header_extension_list:
*
- * Retrieve all the currently registered RTP header extensions
+ * Retrieve all the factories of the currently registered RTP header
+ * extensions. Call gst_element_factory_create() with each factory to create
+ * the associated #GstRTPHeaderExtension.
*
- * Returns: (transfer full) (element-type GstRTPHeaderExtension): a #GList of
- * #GstRTPHeaderExtension. Use gst_plugin_feature_list_free() after use
+ * Returns: (transfer full) (element-type GstElementFactory): a #GList of
+ * #GstElementFactory's. Use gst_plugin_feature_list_free() after use
*
* Since: 1.20
*/