ffmpeg: make elements reusable after registry rescan

If the same instance of the plugin is asked to be initialised more that once,
instances after the first one do not register the elements properly and the
elements become not usable.

For example, if you call gst_update_registry (), is not possible to create
elements after the call since the plugin is asked to be initialised again and
does not register the elements.

Fixes #584291

3 files changed, 46 insertions, 56 deletions

diff --git a/ext/ffmpeg/gstffmpegdec.c b/ext/ffmpeg/gstffmpegdec.c
index 031ba08..45052f5 100644
--- a/ext/ffmpeg/gstffmpegdec.c
+++ b/ext/ffmpeg/gstffmpegdec.c
@@ -2731,20 +2731,18 @@ gst_ffmpegdec_register (GstPlugin * plugin)
     type_name = g_strdup_printf ("ffdec_%s", plugin_name);
     g_free (plugin_name);
 
-    /* if it's already registered, drop it */
-    if (g_type_from_name (type_name)) {
-      g_free (type_name);
-      goto next;
-    }
+    type = g_type_from_name (type_name);
 
-    params = g_new0 (GstFFMpegDecClassParams, 1);
-    params->in_plugin = in_plugin;
-    params->srccaps = gst_caps_ref (srccaps);
-    params->sinkcaps = gst_caps_ref (sinkcaps);
+    if (!type) {
+      params = g_new0 (GstFFMpegDecClassParams, 1);
+      params->in_plugin = in_plugin;
+      params->srccaps = gst_caps_ref (srccaps);
+      params->sinkcaps = gst_caps_ref (sinkcaps);
 
-    /* create the gtype now */
-    type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
-    g_type_set_qdata (type, GST_FFDEC_PARAMS_QDATA, (gpointer) params);
+      /* create the gtype now */
+      type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
+      g_type_set_qdata (type, GST_FFDEC_PARAMS_QDATA, (gpointer) params);
+    }
 
     /* (Ronald) MPEG-4 gets a higher priority because it has been well-
      * tested and by far outperforms divxdec/xviddec - so we prefer it.
diff --git a/ext/ffmpeg/gstffmpegenc.c b/ext/ffmpeg/gstffmpegenc.c
index 767d359..538fbe6 100644
--- a/ext/ffmpeg/gstffmpegenc.c
+++ b/ext/ffmpeg/gstffmpegenc.c
@@ -1177,28 +1177,26 @@ gst_ffmpegenc_register (GstPlugin * plugin)
     /* construct the type */
     type_name = g_strdup_printf ("ffenc_%s", in_plugin->name);
 
-    /* if it's already registered, drop it */
-    if (g_type_from_name (type_name)) {
-      g_free (type_name);
-      goto next;
-    }
-
-    params = g_new0 (GstFFMpegEncClassParams, 1);
-    params->in_plugin = in_plugin;
-    params->srccaps = gst_caps_ref (srccaps);
-    params->sinkcaps = gst_caps_ref (sinkcaps);
-
-    /* create the glib type now */
-    type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
-    g_type_set_qdata (type, GST_FFENC_PARAMS_QDATA, (gpointer) params);
-
-    {
-      static const GInterfaceInfo preset_info = {
-        NULL,
-        NULL,
-        NULL
-      };
-      g_type_add_interface_static (type, GST_TYPE_PRESET, &preset_info);
+    type = g_type_from_name (type_name);
+
+    if (!type) {
+      params = g_new0 (GstFFMpegEncClassParams, 1);
+      params->in_plugin = in_plugin;
+      params->srccaps = gst_caps_ref (srccaps);
+      params->sinkcaps = gst_caps_ref (sinkcaps);
+
+      /* create the glib type now */
+      type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
+      g_type_set_qdata (type, GST_FFENC_PARAMS_QDATA, (gpointer) params);
+
+      {
+        static const GInterfaceInfo preset_info = {
+          NULL,
+          NULL,
+          NULL
+        };
+        g_type_add_interface_static (type, GST_TYPE_PRESET, &preset_info);
+      }
     }
 
     if (!gst_element_register (plugin, type_name, GST_RANK_NONE, type)) {
diff --git a/ext/ffmpeg/gstffmpegmux.c b/ext/ffmpeg/gstffmpegmux.c
index 15cbaf4..5f04d2b 100644
--- a/ext/ffmpeg/gstffmpegmux.c
+++ b/ext/ffmpeg/gstffmpegmux.c
@@ -835,17 +835,6 @@ gst_ffmpegmux_register (GstPlugin * plugin)
       p++;
     }
 
-    /* if it's already registered, drop it */
-    if (g_type_from_name (type_name)) {
-      g_free (type_name);
-      gst_caps_unref (srccaps);
-      if (audiosinkcaps)
-        gst_caps_unref (audiosinkcaps);
-      if (videosinkcaps)
-        gst_caps_unref (videosinkcaps);
-      goto next;
-    }
-
     /* fix up allowed caps for some muxers */
     if (strcmp (in_plugin->name, "flv") == 0) {
       const gint rates[] = { 44100, 22050, 11025 };
@@ -859,17 +848,22 @@ gst_ffmpegmux_register (GstPlugin * plugin)
           gst_caps_from_string ("video/x-raw-rgb, bpp=(int)24, depth=(int)24");
     }
 
-    /* create a cache for these properties */
-    params = g_new0 (GstFFMpegMuxClassParams, 1);
-    params->in_plugin = in_plugin;
-    params->srccaps = srccaps;
-    params->videosinkcaps = videosinkcaps;
-    params->audiosinkcaps = audiosinkcaps;
-
-    /* create the type now */
-    type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
-    g_type_set_qdata (type, GST_FFMUX_PARAMS_QDATA, (gpointer) params);
-    g_type_add_interface_static (type, GST_TYPE_TAG_SETTER, &tag_setter_info);
+    type = g_type_from_name (type_name);
+
+    if (!type) {
+      /* create a cache for these properties */
+      params = g_new0 (GstFFMpegMuxClassParams, 1);
+      params->in_plugin = in_plugin;
+      params->srccaps = srccaps;
+      params->videosinkcaps = videosinkcaps;
+      params->audiosinkcaps = audiosinkcaps;
+
+      /* create the type now */
+      type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
+      g_type_set_qdata (type, GST_FFMUX_PARAMS_QDATA, (gpointer) params);
+      g_type_add_interface_static (type, GST_TYPE_TAG_SETTER, &tag_setter_info);
+
+    }
 
     if (!gst_element_register (plugin, type_name, GST_RANK_NONE, type)) {
       g_free (type_name);