taglib: allow per feature registration

Split plugin into features including
dynamic types which can be indiviually
registered during a static build.

More details here:

https://gitlab.freedesktop.org/gstreamer/gst-build/-/merge_requests/199
https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/661

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/876>

ext/taglib/gstapev2mux.cc

@@ -46,6 +46,7 @@
 #include <config.h>
 #endif
 
+#include "gsttaglibelements.h"
 #include "gstapev2mux.h"
 
 #include <string.h>
@@ -69,6 +70,10 @@ static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
     GST_STATIC_CAPS ("ANY"));
 
 G_DEFINE_TYPE (GstApev2Mux, gst_apev2_mux, GST_TYPE_TAG_MUX);
+#define _do_init \
+  taglib_element_init (plugin);
+GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (apev2mux, "apev2mux",
+    GST_RANK_NONE, GST_TYPE_APEV2_MUX, _do_init);
 
 static GstBuffer *gst_apev2_mux_render_start_tag (GstTagMux * mux,
     const GstTagList * taglist);

ext/taglib/gstid3v2mux.cc

@@ -47,6 +47,7 @@
 #include <config.h>
 #endif
 
+#include "gsttaglibelements.h"
 #include "gstid3v2mux.h"
 
 #include <string.h>
@@ -77,6 +78,10 @@ static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
     GST_STATIC_CAPS ("ANY"));
 
 G_DEFINE_TYPE (GstId3v2Mux, gst_id3v2_mux, GST_TYPE_TAG_MUX);
+#define _do_init \
+  taglib_element_init (plugin);
+GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (id3v2mux, "id3v2mux",
+    GST_RANK_NONE, GST_TYPE_ID3V2_MUX, _do_init);
 
 static GstBuffer *gst_id3v2_mux_render_tag (GstTagMux * mux,
     const GstTagList * taglist);

ext/taglib/gsttaglibelement.c

@@ -0,0 +1,38 @@
+/* GStreamer taglib-based muxer base class
+ * Copyright (C) 2006 Christophe Fergeau  <teuf@gnome.org>
+ * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
+ * Copyright (C) 2006 Sebastian Dröge <slomo@circular-chaos.org>
+
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "gsttaglibelements.h"
+
+#include <gst/tag/tag.h>
+
+void
+taglib_element_init (GstPlugin * plugin)
+{
+  static gsize res = FALSE;
+  if (g_once_init_enter (&res)) {
+    gst_tag_register_musicbrainz_tags ();
+    g_once_init_leave (&res, TRUE);
+  }
+}

ext/taglib/gsttaglibelements.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2020 Huawei Technologies Co., Ltd.
+ *   @Author: Julian Bouzas <julian.bouzas@collabora.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_TAGLIB_ELEMENTS_H__
+#define __GST_TAGLIB_ELEMENTS_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+void taglib_element_init (GstPlugin * plugin);
+
+GST_ELEMENT_REGISTER_DECLARE (id3v2mux);
+GST_ELEMENT_REGISTER_DECLARE (apev2mux);
+
+G_END_DECLS
+
+#endif /* __GST_TAGLIB_ELEMENTS_H__ */

ext/taglib/gsttaglibplugin.c

@@ -23,23 +23,19 @@
 #include <config.h>
 #endif
 
-#include "gstapev2mux.h"
+#include "gsttaglibelements.h"
-#include "gstid3v2mux.h"
 
 #include <gst/tag/tag.h>
 
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
-  if (!gst_element_register (plugin, "id3v2mux", GST_RANK_NONE,
+  gboolean ret = FALSE;
-          GST_TYPE_ID3V2_MUX) ||
-      !gst_element_register (plugin, "apev2mux", GST_RANK_NONE,
-          GST_TYPE_APEV2_MUX))
-    return FALSE;
 
-  gst_tag_register_musicbrainz_tags ();
+  ret |= GST_ELEMENT_REGISTER (id3v2mux, plugin);
+  ret |= GST_ELEMENT_REGISTER (apev2mux, plugin);
 
-  return TRUE;
+  return ret;
 }
 
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,

ext/taglib/meson.build

@@ -1,6 +1,7 @@
 taglib_sources = [
   'gstapev2mux.cc',
   'gstid3v2mux.cc',
+  'gsttaglibelement.c',
   'gsttaglibplugin.c',
 ]