When compiling the docs I notice these warnings:

gstbufferpool.c:1087: Warning: Gst: missing ":" at column 41:
 * @params: (transfer none) (allow-none) parameters.
                                        ^
gstmeta.c:153: Warning: Gst: missing ":" at column 29:
 * @init_func: (scope async) a #GstMetaInitFunction
                            ^
gstmeta.c:154: Warning: Gst: missing ":" at column 29:
 * @free_func: (scope async) a #GstMetaFreeFunction
                            ^
gstmeta.c:155: Warning: Gst: missing ":" at column 34:
 * @transform_func: (scope async) a #GstMetaTransformFunction
                                 ^

The propposed patch will remove these and remove the usage of
unrecognized (optional) and (replacement) annotations used in
GstBaseParseFrame. These two annotation tags are neither known
by gtk-doc nor by gobject-introspection.