wpe: Make wpesrc!video pad an always pad

There should always be a `video` pad no matter what.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2273>

docs/plugins/gst_plugins_cache.json

@@ -229248,7 +229248,7 @@
                     "video": {
                         "caps": "video/x-raw(memory:GLMemory):\n         format: RGBA\n          width: [ 1, 2147483647 ]\n         height: [ 1, 2147483647 ]\n      framerate: [ 0/1, 2147483647/1 ]\npixel-aspect-ratio: 1/1\n texture-target: 2D\nvideo/x-raw:\n         format: BGRA\n          width: [ 1, 2147483647 ]\n         height: [ 1, 2147483647 ]\n      framerate: [ 0/1, 2147483647/1 ]\npixel-aspect-ratio: 1/1\n",
                         "direction": "src",
-                        "presence": "sometimes"
+                        "presence": "always"
                     }
                 },
                 "properties": {

ext/wpe/gstwpesrcbin.cpp

@@ -173,7 +173,7 @@ G_DEFINE_TYPE_WITH_CODE (GstWpeSrc, gst_wpe_src, GST_TYPE_BIN,
  * Since: 1.20
  */
 static GstStaticPadTemplate video_src_factory =
-GST_STATIC_PAD_TEMPLATE ("video", GST_PAD_SRC, GST_PAD_SOMETIMES,
+GST_STATIC_PAD_TEMPLATE ("video", GST_PAD_SRC, GST_PAD_ALWAYS,
     GST_STATIC_CAPS ("video/x-raw(memory:GLMemory), "
                      "format = (string) RGBA, "
                      "width = " GST_VIDEO_SIZE_RANGE ", "
@@ -360,32 +360,7 @@ gst_wpe_src_load_bytes (GstWpeVideoSrc * src, GBytes * bytes)
 static void
 gst_wpe_src_set_location (GstWpeSrc * src, const gchar * location)
 {
-  GstPad *pad;
-  GstPad *ghost_pad;
-  GstProxyPad *proxy_pad;
-
   g_object_set (src->video_src, "location", location, NULL);
-
-  ghost_pad = gst_element_get_static_pad (GST_ELEMENT_CAST (src), "video");
-  if (GST_IS_PAD (ghost_pad)) {
-    gst_object_unref (ghost_pad);
-    return;
-  }
-
-  gst_bin_add (GST_BIN_CAST (src), src->video_src);
-
-  pad = gst_element_get_static_pad (GST_ELEMENT_CAST (src->video_src), "src");
-  ghost_pad = gst_ghost_pad_new_from_template ("video", pad,
-    gst_static_pad_template_get (&video_src_factory));
-  proxy_pad = gst_proxy_pad_get_internal (GST_PROXY_PAD (ghost_pad));
-  gst_pad_set_active (GST_PAD_CAST (proxy_pad), TRUE);
-
-  gst_element_add_pad (GST_ELEMENT_CAST (src), GST_PAD_CAST (ghost_pad));
-  gst_flow_combiner_add_pad (src->flow_combiner, GST_PAD_CAST (ghost_pad));
-  gst_pad_set_chain_function (GST_PAD_CAST (proxy_pad), gst_wpe_src_chain_buffer);
-
-  gst_object_unref (proxy_pad);
-  gst_object_unref (pad);
 }
 
 static void
@@ -463,6 +438,10 @@ gst_wpe_src_uri_handler_init (gpointer iface_ptr, gpointer data)
 static void
 gst_wpe_src_init (GstWpeSrc * src)
 {
+  GstPad *pad;
+  GstPad *ghost_pad;
+  GstProxyPad *proxy_pad;
+
   gst_bin_set_suppressed_flags (GST_BIN_CAST (src),
       static_cast<GstElementFlags>(GST_ELEMENT_FLAG_SOURCE | GST_ELEMENT_FLAG_SINK));
   GST_OBJECT_FLAG_SET (src, GST_ELEMENT_FLAG_SOURCE);
@@ -471,6 +450,21 @@ gst_wpe_src_init (GstWpeSrc * src)
   src->audio_src_pads = g_hash_table_new (g_direct_hash, g_direct_equal);
   src->flow_combiner = gst_flow_combiner_new ();
   src->video_src = gst_element_factory_make ("wpevideosrc", NULL);
+
+  gst_bin_add (GST_BIN_CAST (src), src->video_src);
+
+  pad = gst_element_get_static_pad (GST_ELEMENT_CAST (src->video_src), "src");
+  ghost_pad = gst_ghost_pad_new_from_template ("video", pad,
+    gst_static_pad_template_get (&video_src_factory));
+  proxy_pad = gst_proxy_pad_get_internal (GST_PROXY_PAD (ghost_pad));
+  gst_pad_set_active (GST_PAD_CAST (proxy_pad), TRUE);
+
+  gst_element_add_pad (GST_ELEMENT_CAST (src), GST_PAD_CAST (ghost_pad));
+  gst_flow_combiner_add_pad (src->flow_combiner, GST_PAD_CAST (ghost_pad));
+  gst_pad_set_chain_function (GST_PAD_CAST (proxy_pad), gst_wpe_src_chain_buffer);
+
+  gst_object_unref (proxy_pad);
+  gst_object_unref (pad);
 }
 
 static gboolean

tests/examples/wpe/wpe.c

@@ -80,16 +80,8 @@ _wpe_pad_added (GstElement * src, GstPad * new_pad, GstElement * pipe)
   gchar *name = gst_pad_get_name (new_pad);
   gchar *bin_name;
 
-  if (g_str_has_prefix (name, "audio")) {
+  out = gst_parse_bin_from_description
-    out =
+      ("audioresample ! audioconvert ! autoaudiosink", TRUE, NULL);
-        gst_parse_bin_from_description
-        ("audioresample ! audioconvert ! autoaudiosink", TRUE, NULL);
-  } else {
-    out =
-        gst_parse_bin_from_description
-        ("queue ! glcolorconvert ! gtkglsink enable-last-sample=0", TRUE, NULL);
-  }
-
   bin_name = g_strdup_printf ("%s-bin", name);
   g_free (name);
 
@@ -130,19 +122,22 @@ main (int argc, char *argv[])
   gst_init (&argc, &argv);
 
   loop = g_main_loop_new (NULL, FALSE);
-  pipe1 = gst_pipeline_new (NULL);
+  pipe1 =
+      gst_parse_launch
+      ("wpesrc name=wpesrc ! queue ! glcolorconvert ! gtkglsink enable-last-sample=0",
+      NULL);
   bus1 = gst_pipeline_get_bus (GST_PIPELINE (pipe1));
   gst_bus_add_watch (bus1, (GstBusFunc) _bus_watch, pipe1);
 
-  src = gst_element_factory_make ("wpesrc", NULL);
+  src = gst_bin_get_by_name (GST_BIN (pipe1), "wpesrc");
 
-  gst_bin_add (GST_BIN_CAST (pipe1), src);
   gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_READY);
 
   g_signal_connect (src, "pad-added", G_CALLBACK (_wpe_pad_added), pipe1);
   g_signal_connect (src, "pad-removed", G_CALLBACK (_wpe_pad_removed), pipe1);
 
   g_object_set (src, "location", argv[1], NULL);
+  gst_clear_object (&src);
 
   g_print ("Starting pipeline\n");
   gst_element_set_state (GST_ELEMENT (pipe1), GST_STATE_PLAYING);