openh264: 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-bad/-/merge_requests/2038>

ext/openh264/gstopenh264dec.cpp

@@ -27,6 +27,7 @@
 #include "config.h"
 #endif
 
+#include "gstopenh264elements.h"
 #include "gstopenh264dec.h"
 
 #include <wels/codec_ver.h>
@@ -59,6 +60,7 @@ static GstFlowReturn gst_openh264dec_handle_frame (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame);
 static gboolean gst_openh264dec_decide_allocation (GstVideoDecoder * decoder,
     GstQuery * query);
+static gboolean openh264dec_element_init (GstPlugin * plugin);
 
 #if HAVE_OPENH264_MAIN_PROFILE
 #define SUPPORTED_PROFILE_STR "profile=(string){ constrained-baseline, baseline, main, high, constrained-high, progressive-high }"
@@ -88,6 +90,7 @@ G_DEFINE_TYPE_WITH_CODE (GstOpenh264Dec, gst_openh264dec,
     GST_TYPE_VIDEO_DECODER,
     GST_DEBUG_CATEGORY_INIT (gst_openh264dec_debug_category, "openh264dec", 0,
         "debug category for openh264dec element"));
+GST_ELEMENT_REGISTER_DEFINE_CUSTOM (openh264dec, openh264dec_element_init);
 
 static void
 gst_openh264dec_class_init (GstOpenh264DecClass * klass)
@@ -448,3 +451,14 @@ gst_openh264dec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
 
   return TRUE;
 }
+
+static gboolean
+openh264dec_element_init (GstPlugin * plugin)
+{
+  if (openh264_element_init (plugin))
+    return gst_element_register (plugin, "openh264dec", GST_RANK_MARGINAL,
+        GST_TYPE_OPENH264DEC);
+
+ GST_ERROR ("Incorrect library version loaded, expecting %s", g_strCodecVer);
+ return FALSE;
+}

ext/openh264/gstopenh264element.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2014, Ericsson AB. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this
+ * list of conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gst/gst.h>
+#include <wels/codec_api.h>
+#include <wels/codec_ver.h>
+#include <string.h>
+#include "gstopenh264elements.h"
+
+
+gboolean
+openh264_element_init (GstPlugin * plugin)
+{
+  static gsize res = FALSE;
+
+  if (g_once_init_enter (&res)) {
+    gsize value;
+    OpenH264Version libver;
+    /* g_stCodecVersion is the version detected at build time as defined in the
+     * headers and WelsGetCodecVersion() is the version detected at runtime.
+     * This is a safeguard to avoid crashes since OpenH264  has been changing
+     * ABI without changing the SONAME.
+     */
+    libver = WelsGetCodecVersion ();
+    value = memcmp (&libver, &g_stCodecVersion, sizeof (libver)) == 0;
+    g_once_init_leave (&res, value);
+  }
+
+  return res;
+}

ext/openh264/gstopenh264elements.h

@@ -0,0 +1,37 @@
+/* GStreamer
+ * Copyright (C) <2020> The GStreamer Contributors.
+ *
+ * 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_OPENH264_ELEMENT_H__
+#define __GST_OPENH264_ELEMENT_H__
+
+#include <config.h>
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+gboolean openh264_element_init (GstPlugin * plugin);
+
+GST_ELEMENT_REGISTER_DECLARE (openh264dec);
+GST_ELEMENT_REGISTER_DECLARE (openh264enc);
+
+G_END_DECLS
+
+#endif /* __GST_OPENH264_ELEMENT_H__ */

ext/openh264/gstopenh264enc.cpp

@@ -27,6 +27,7 @@
 #include "config.h"
 #endif
 
+#include "gstopenh264elements.h"
 #include "gstopenh264enc.h"
 
 #include <gst/gst.h>
@@ -162,6 +163,7 @@ static void gst_openh264enc_set_usage_type (GstOpenh264Enc * openh264enc,
     gint usage_type);
 static void gst_openh264enc_set_rate_control (GstOpenh264Enc * openh264enc,
     gint rc_mode);
+static gboolean openh264enc_element_init (GstPlugin * plugin);
 
 
 #define DEFAULT_BITRATE            (128000)
@@ -235,6 +237,7 @@ G_DEFINE_TYPE_WITH_CODE (GstOpenh264Enc, gst_openh264enc,
     G_IMPLEMENT_INTERFACE (GST_TYPE_PRESET, NULL);
     GST_DEBUG_CATEGORY_INIT (gst_openh264enc_debug_category, "openh264enc", 0,
         "debug category for openh264enc element"));
+GST_ELEMENT_REGISTER_DEFINE_CUSTOM (openh264enc, openh264enc_element_init);
 
 static void
 gst_openh264enc_class_init (GstOpenh264EncClass * klass)
@@ -1056,3 +1059,13 @@ gst_openh264enc_finish (GstVideoEncoder * encoder)
 
   return GST_FLOW_OK;
 }
+static gboolean
+openh264enc_element_init (GstPlugin * plugin)
+{
+  if (openh264_element_init (plugin))
+    return gst_element_register (plugin, "openh264enc", GST_RANK_MARGINAL,
+                                 GST_TYPE_OPENH264ENC);
+
+ GST_ERROR ("Incorrect library version loaded, expecting %s", g_strCodecVer);
+ return FALSE;
+}

ext/openh264/gstopenh264plugin.c

@@ -31,31 +31,18 @@
 #include <config.h>
 #endif
 
-#include <gst/gst.h>
+#include "gstopenh264elements.h"
-#include <wels/codec_api.h>
+
-#include <wels/codec_ver.h>
-#include <string.h>
-#include "gstopenh264dec.h"
-#include "gstopenh264enc.h"
 
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
-  /* g_stCodecVersion is the version detected at build time as defined in the
+  gboolean ret = FALSE;
-   * headers and WelsGetCodecVersion() is the version detected at runtime.
+
-   * This is a safeguard to avoid crashes since OpenH264  has been changing
+  ret |= GST_ELEMENT_REGISTER (openh264dec, plugin);
-   * ABI without changing the SONAME.
+  ret |= GST_ELEMENT_REGISTER (openh264enc, plugin);
-   */
+
-  OpenH264Version libver = WelsGetCodecVersion ();
+  return ret;
-  if (memcmp (&libver, &g_stCodecVersion, sizeof (libver)) == 0) {
-    gst_element_register (plugin, "openh264dec", GST_RANK_MARGINAL,
-        GST_TYPE_OPENH264DEC);
-    gst_element_register (plugin, "openh264enc", GST_RANK_MARGINAL,
-        GST_TYPE_OPENH264ENC);
-  } else {
-    GST_ERROR ("Incorrect library version loaded, expecting %s", g_strCodecVer);
-  }
-  return TRUE;
 }
 
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,

ext/openh264/meson.build

@@ -1,6 +1,7 @@
 openh264_sources = [
   'gstopenh264dec.cpp',
   'gstopenh264enc.cpp',
+  'gstopenh264element.c',
   'gstopenh264plugin.c',
 ]