plugin: gluploader: Remove DMABuf caps features on GLX

GLX cannot do DMABufs. Do not advertise its support in caps, so upstream elements will never try using this kind of memory on GLX.

lib/gst/plugin/importers/gstclappergluploader.c

@@ -22,6 +22,11 @@
 #endif
 
 #include "gstclappergluploader.h"
+#include "gst/plugin/gstgtkutils.h"
+
+#if GST_CLAPPER_GL_BASE_IMPORTER_HAVE_X11
+#include <gdk/x11/gdkx.h>
+#endif
 
 #define GST_CAT_DEFAULT gst_clapper_gl_uploader_debug
 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
@@ -222,11 +227,59 @@ make_importer (void)
   return g_object_new (GST_TYPE_CLAPPER_GL_UPLOADER, NULL);
 }
 
+#if GST_CLAPPER_GL_BASE_IMPORTER_HAVE_X11_GLX
+static gboolean
+_filter_glx_caps_cb (GstCapsFeatures *features,
+    GstStructure *structure, gpointer user_data)
+{
+  return !gst_caps_features_contains (features, "memory:DMABuf");
+}
+
+static gboolean
+_update_glx_caps_on_main (GstCaps *caps)
+{
+  GdkDisplay *gdk_display;
+
+  if (!gtk_init_check ())
+    return FALSE;
+
+  gdk_display = gdk_display_get_default ();
+  if (G_UNLIKELY (!gdk_display))
+    return FALSE;
+
+  if (GDK_IS_X11_DISPLAY (gdk_display)) {
+    gboolean using_glx = TRUE;
+
+#if GST_CLAPPER_GL_BASE_IMPORTER_HAVE_X11_EGL
+    using_glx = (gdk_x11_display_get_egl_display (gdk_display) == NULL);
+#endif
+
+    if (using_glx) {
+      gst_caps_filter_and_map_in_place (caps,
+          (GstCapsFilterMapFunc) _filter_glx_caps_cb, NULL);
+    }
+  }
+
+  return TRUE;
+}
+#endif
+
 GstCaps *
 make_caps (GstRank *rank, GStrv *context_types)
 {
+  GstCaps *caps = gst_gl_upload_get_input_template_caps ();
+
+#if GST_CLAPPER_GL_BASE_IMPORTER_HAVE_X11_GLX
+  if (!(! !gst_gtk_invoke_on_main ((GThreadFunc) (GCallback)
+      _update_glx_caps_on_main, caps)))
+    gst_clear_caps (&caps);
+#endif
+
+  if (G_UNLIKELY (!caps))
+    return NULL;
+
   *rank = GST_RANK_MARGINAL + 1;
   *context_types = gst_clapper_gl_base_importer_make_gl_context_types ();
 
-  return gst_gl_upload_get_input_template_caps ();
+  return caps;
 }