gl: propogate other-context using GstContext

ext/gl/gstglimagesink.c

@@ -173,8 +173,7 @@ enum
   ARG_DISPLAY,
   PROP_FORCE_ASPECT_RATIO,
   PROP_PIXEL_ASPECT_RATIO,
-  PROP_CONTEXT,
+  PROP_CONTEXT
-  PROP_OTHER_CONTEXT
 };
 
 enum
@@ -277,12 +276,6 @@ gst_glimage_sink_class_init (GstGLImageSinkClass * klass)
           "The pixel aspect ratio of the device", 0, 1, G_MAXINT, 1, 1, 1,
           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
-  g_object_class_install_property (gobject_class, PROP_OTHER_CONTEXT,
-      g_param_spec_object ("other-context",
-          "External OpenGL context",
-          "Give an external OpenGL context with which to share textures",
-          GST_GL_TYPE_CONTEXT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
-
   g_object_class_install_property (gobject_class, PROP_CONTEXT,
       g_param_spec_object ("context",
           "OpenGL context",
@@ -393,13 +386,6 @@ gst_glimage_sink_set_property (GObject * object, guint prop_id,
       glimage_sink->par_d = gst_value_get_fraction_denominator (value);
       break;
     }
-    case PROP_OTHER_CONTEXT:
-    {
-      if (glimage_sink->other_context)
-        gst_object_unref (glimage_sink->other_context);
-      glimage_sink->other_context = g_value_dup_object (value);
-      break;
-    }
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -451,9 +437,6 @@ gst_glimage_sink_get_property (GObject * object, guint prop_id,
     case PROP_CONTEXT:
       g_value_set_object (value, glimage_sink->context);
       break;
-    case PROP_OTHER_CONTEXT:
-      g_value_set_object (value, glimage_sink->other_context);
-      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -485,7 +468,7 @@ _ensure_gl_setup (GstGLImageSink * gl_sink)
 {
   GError *error = NULL;
 
-  if (!gst_gl_ensure_display (gl_sink, &gl_sink->display))
+  if (!gst_gl_ensure_element_data (gl_sink, &gl_sink->display, &gl_sink->other_context))
     return FALSE;
 
   if (!gl_sink->context) {
@@ -558,7 +541,7 @@ gst_glimage_sink_query (GstBaseSink * bsink, GstQuery * query)
     case GST_QUERY_CONTEXT:
     {
       return gst_gl_handle_context_query ((GstElement *) glimage_sink, query,
-          &glimage_sink->display);
+          &glimage_sink->display, &glimage_sink->other_context);
     }
     default:
       res = GST_BASE_SINK_CLASS (parent_class)->query (bsink, query);
@@ -601,7 +584,7 @@ gst_glimage_sink_set_context (GstElement * element, GstContext * context)
 {
   GstGLImageSink *gl_sink = GST_GLIMAGE_SINK (element);
 
-  gst_gl_handle_set_context (element, context, &gl_sink->display);
+  gst_gl_handle_set_context (element, context, &gl_sink->display, &gl_sink->other_context);
 }
 
 static GstStateChangeReturn
@@ -622,7 +605,7 @@ gst_glimage_sink_change_state (GstElement * element, GstStateChange transition)
     case GST_STATE_CHANGE_READY_TO_PAUSED:
       g_atomic_int_set (&glimage_sink->to_quit, 0);
       if (!glimage_sink->display) {
-        if (!gst_gl_ensure_display (glimage_sink, &glimage_sink->display))
+        if (!gst_gl_ensure_element_data (glimage_sink, &glimage_sink->display, &glimage_sink->other_context))
           return GST_STATE_CHANGE_FAILURE;
       }
       break;

ext/gl/gstglmixer.c

@@ -183,7 +183,7 @@ gst_gl_mixer_propose_allocation (GstGLMixer * mix,
     gst_structure_free (config);
   }
 
-  if (!gst_gl_ensure_display (mix, &mix->display))
+  if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
     return FALSE;
 
   if (!mix->context) {
@@ -308,7 +308,7 @@ gst_gl_mixer_sink_query (GstAggregator * agg, GstAggregatorPad * bpad,
     case GST_QUERY_CONTEXT:
     {
       ret = gst_gl_handle_context_query ((GstElement *) mix, query,
-          &mix->display);
+          &mix->display, &mix->other_context);
       break;
     }
     default:
@@ -333,8 +333,7 @@ enum
 
 enum
 {
-  PROP_0,
+  PROP_0
-  PROP_OTHER_CONTEXT
 };
 
 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
@@ -410,12 +409,6 @@ gst_gl_mixer_class_init (GstGLMixerClass * klass)
   gobject_class->get_property = gst_gl_mixer_get_property;
   gobject_class->set_property = gst_gl_mixer_set_property;
 
-  g_object_class_install_property (gobject_class, PROP_OTHER_CONTEXT,
-      g_param_spec_object ("other-context",
-          "External OpenGL context",
-          "Give an external OpenGL context with which to share textures",
-          GST_GL_TYPE_CONTEXT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
-
   gst_element_class_add_pad_template (element_class,
       gst_static_pad_template_get (&src_factory));
   gst_element_class_add_pad_template (element_class,
@@ -487,7 +480,7 @@ gst_gl_mixer_set_context (GstElement * element, GstContext * context)
 {
   GstGLMixer *mix = GST_GL_MIXER (element);
 
-  gst_gl_handle_set_context (element, context, &mix->display);
+  gst_gl_handle_set_context (element, context, &mix->display, &mix->context);
 }
 
 static gboolean
@@ -496,7 +489,7 @@ gst_gl_mixer_activate (GstGLMixer * mix, gboolean active)
   gboolean result = TRUE;
 
   if (active) {
-    if (!gst_gl_ensure_display (mix, &mix->display))
+    if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
       result = FALSE;
   }
 
@@ -665,7 +658,7 @@ gst_gl_mixer_src_query (GstAggregator * agg, GstQuery * query)
     case GST_QUERY_CONTEXT:
     {
       res = gst_gl_handle_context_query ((GstElement *) mix, query,
-          &mix->display);
+          &mix->display, &mix->other_context);
       break;
     }
     case GST_QUERY_CAPS:
@@ -712,7 +705,7 @@ gst_gl_mixer_decide_allocation (GstGLMixer * mix, GstQuery * query)
   GstGLContext *other_context = NULL;
   GstVideoAggregator *vagg = GST_VIDEO_AGGREGATOR (mix);
 
-  if (!gst_gl_ensure_display (mix, &mix->display))
+  if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
     return FALSE;
 
   if (gst_query_find_allocation_meta (query,
@@ -1121,12 +1114,7 @@ static void
 gst_gl_mixer_get_property (GObject * object,
     guint prop_id, GValue * value, GParamSpec * pspec)
 {
-  GstGLMixer *mix = GST_GL_MIXER (object);
-
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-      g_value_set_object (value, mix->other_context);
-      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -1137,16 +1125,7 @@ static void
 gst_gl_mixer_set_property (GObject * object,
     guint prop_id, const GValue * value, GParamSpec * pspec)
 {
-  GstGLMixer *mix = GST_GL_MIXER (object);
-
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-    {
-      if (mix->other_context)
-        gst_object_unref (mix->other_context);
-      mix->other_context = g_value_dup_object (value);
-      break;
-    }
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;

ext/gl/gstgltestsrc.c

@@ -59,7 +59,6 @@ GST_DEBUG_CATEGORY_STATIC (gl_test_src_debug);
 enum
 {
   PROP_0,
-  PROP_OTHER_CONTEXT,
   PROP_PATTERN,
   PROP_TIMESTAMP_OFFSET,
   PROP_IS_LIVE
@@ -165,11 +164,6 @@ gst_gl_test_src_class_init (GstGLTestSrcClass * klass)
   gobject_class->get_property = gst_gl_test_src_get_property;
   gobject_class->dispose = gst_gl_test_src_dispose;
 
-  g_object_class_install_property (gobject_class, PROP_OTHER_CONTEXT,
-      g_param_spec_object ("other-context",
-          "External OpenGL context",
-          "Give an external OpenGL context with which to share textures",
-          GST_GL_TYPE_CONTEXT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   g_object_class_install_property (gobject_class, PROP_PATTERN,
       g_param_spec_enum ("pattern", "Pattern",
           "Type of test pattern to generate", GST_TYPE_GL_TEST_SRC_PATTERN,
@@ -415,11 +409,6 @@ gst_gl_test_src_set_property (GObject * object, guint prop_id,
   GstGLTestSrc *src = GST_GL_TEST_SRC (object);
 
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-      if (src->other_context)
-        gst_object_unref (src->other_context);
-      src->other_context = g_value_dup_object (value);
-      break;
     case PROP_PATTERN:
       gst_gl_test_src_set_pattern (src, g_value_get_enum (value));
       break;
@@ -441,9 +430,6 @@ gst_gl_test_src_get_property (GObject * object, guint prop_id,
   GstGLTestSrc *src = GST_GL_TEST_SRC (object);
 
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-      g_value_set_object (value, src->other_context);
-      break;
     case PROP_PATTERN:
       g_value_set_enum (value, src->pattern_type);
       break;
@@ -488,7 +474,7 @@ gst_gl_test_src_set_context (GstElement * element, GstContext * context)
 {
   GstGLTestSrc *src = GST_GL_TEST_SRC (element);
 
-  gst_gl_handle_set_context (element, context, &src->display);
+  gst_gl_handle_set_context (element, context, &src->display, &src->other_context);
 }
 
 static gboolean
@@ -503,7 +489,7 @@ gst_gl_test_src_query (GstBaseSrc * bsrc, GstQuery * query)
     case GST_QUERY_CONTEXT:
     {
       res = gst_gl_handle_context_query ((GstElement *) src, query,
-          &src->display);
+          &src->display, &src->other_context);
       break;
     }
     case GST_QUERY_CONVERT:
@@ -712,7 +698,7 @@ gst_gl_test_src_start (GstBaseSrc * basesrc)
 {
   GstGLTestSrc *src = GST_GL_TEST_SRC (basesrc);
 
-  if (!gst_gl_ensure_display (src, &src->display))
+  if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
     return FALSE;
 
   src->running_time = 0;
@@ -771,7 +757,7 @@ gst_gl_test_src_decide_allocation (GstBaseSrc * basesrc, GstQuery * query)
   guint out_width, out_height;
   GstGLContext *other_context = NULL;
 
-  if (!gst_gl_ensure_display (src, &src->display))
+  if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
     return FALSE;
 
   if (gst_query_find_allocation_meta (query,

gst-libs/gst/gl/gstglfilter.c

@@ -71,8 +71,7 @@ static GstStaticPadTemplate gst_gl_filter_sink_pad_template =
 /* Properties */
 enum
 {
-  PROP_0,
+  PROP_0
-  PROP_OTHER_CONTEXT
 };
 
 #define DEBUG_INIT \
@@ -140,12 +139,6 @@ gst_gl_filter_class_init (GstGLFilterClass * klass)
 
   element_class->set_context = gst_gl_filter_set_context;
 
-  g_object_class_install_property (gobject_class, PROP_OTHER_CONTEXT,
-      g_param_spec_object ("other-context",
-          "External OpenGL context",
-          "Give an external OpenGL context with which to share textures",
-          GST_GL_TYPE_CONTEXT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
-
   gst_element_class_add_pad_template (element_class,
       gst_static_pad_template_get (&gst_gl_filter_src_pad_template));
   gst_element_class_add_pad_template (element_class,
@@ -172,16 +165,7 @@ static void
 gst_gl_filter_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
 {
-  GstGLFilter *filter = GST_GL_FILTER (object);
-
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-    {
-      if (filter->other_context)
-        gst_object_unref (filter->other_context);
-      filter->other_context = g_value_dup_object (value);
-      break;
-    }
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -192,12 +176,7 @@ static void
 gst_gl_filter_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec)
 {
-  GstGLFilter *filter = GST_GL_FILTER (object);
-
   switch (prop_id) {
-    case PROP_OTHER_CONTEXT:
-      g_value_set_object (value, filter->other_context);
-      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -209,7 +188,8 @@ gst_gl_filter_set_context (GstElement * element, GstContext * context)
 {
   GstGLFilter *filter = GST_GL_FILTER (element);
 
-  gst_gl_handle_set_context (element, context, &filter->display);
+  gst_gl_handle_set_context (element, context, &filter->display,
+      &filter->other_context);
 }
 
 static gboolean
@@ -231,7 +211,7 @@ gst_gl_filter_query (GstBaseTransform * trans, GstPadDirection direction,
     case GST_QUERY_CONTEXT:
     {
       return gst_gl_handle_context_query ((GstElement *) filter, query,
-          &filter->display);
+          &filter->display, &filter->other_context);
     }
     default:
       break;
@@ -314,7 +294,7 @@ gst_gl_filter_start (GstBaseTransform * bt)
   GstGLFilter *filter = GST_GL_FILTER (bt);
   GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (filter);
 
-  if (!gst_gl_ensure_display (filter, &filter->display))
+  if (!gst_gl_ensure_element_data (filter, &filter->display, &filter->other_context))
     return FALSE;
 
   if (filter_class->onStart)
@@ -894,7 +874,7 @@ gst_gl_filter_propose_allocation (GstBaseTransform * trans,
     gst_structure_free (config);
   }
 
-  if (!gst_gl_ensure_display (filter, &filter->display))
+  if (!gst_gl_ensure_element_data (filter, &filter->display, &filter->other_context))
     return FALSE;
 
   if (!filter->context) {
@@ -1015,7 +995,7 @@ gst_gl_filter_decide_allocation (GstBaseTransform * trans, GstQuery * query)
   guint in_width, in_height, out_width, out_height;
   GstGLContext *other_context = NULL;
 
-  if (!gst_gl_ensure_display (filter, &filter->display))
+  if (!gst_gl_ensure_element_data (filter, &filter->display, &filter->other_context))
     return FALSE;
 
   if (gst_query_find_allocation_meta (query,
@@ -1262,7 +1242,7 @@ gst_gl_filter_transform (GstBaseTransform * bt, GstBuffer * inbuf,
   filter = GST_GL_FILTER (bt);
   filter_class = GST_GL_FILTER_GET_CLASS (bt);
 
-  if (!gst_gl_ensure_display (filter, &filter->display))
+  if (!gst_gl_ensure_element_data (filter, &filter->display, &filter->other_context))
     return GST_FLOW_NOT_NEGOTIATED;
 
   if (!filter->upload) {

gst-libs/gst/gl/gstglutils.c

@@ -592,8 +592,8 @@ run_context_query (GstElement * element, GstQuery * query,
 }
 
 static GstQuery *
-_gst_gl_display_context_query (GstElement * element,
+_gst_context_query (GstElement * element,
-    GstGLDisplay ** display_ptr, const gchar * display_type)
+    gpointer ptr, const gchar * display_type)
 {
   GstQuery *query;
   GstContext *ctxt;
@@ -637,8 +637,7 @@ _gst_gl_display_context_query (GstElement * element,
 }
 
 static void
-gst_gl_display_context_prepare (GstElement * element,
+gst_gl_display_context_query (GstElement * element, GstGLDisplay ** display_ptr)
-    GstGLDisplay ** display_ptr)
 {
   GstContext *ctxt;
   GstQuery *query;
@@ -649,8 +648,7 @@ gst_gl_display_context_prepare (GstElement * element,
 #endif
 
   query =
-      _gst_gl_display_context_query (element, display_ptr,
+      _gst_context_query (element, display_ptr, GST_GL_DISPLAY_CONTEXT_TYPE);
-      GST_GL_DISPLAY_CONTEXT_TYPE);
   gst_query_parse_context (query, &ctxt);
   if (ctxt && gst_context_has_context_type (ctxt, GST_GL_DISPLAY_CONTEXT_TYPE)) {
     gst_context_get_gl_display (ctxt, display_ptr);
@@ -659,9 +657,7 @@ gst_gl_display_context_prepare (GstElement * element,
   }
 #if GST_GL_HAVE_WINDOW_X11
   gst_query_unref (query);
-  query =
+  query = _gst_context_query (element, display_ptr, "gst.x11.display.handle");
-      _gst_gl_display_context_query (element, display_ptr,
-      "gst.x11.display.handle");
   gst_query_parse_context (query, &ctxt);
   if (ctxt && gst_context_has_context_type (ctxt, "gst.x11.display.handle")) {
     const GstStructure *s;
@@ -681,6 +677,27 @@ out:
   gst_query_unref (query);
 }
 
+static void
+gst_gl_context_query (GstElement * element, GstGLContext ** context_ptr)
+{
+  GstContext *ctxt;
+  GstQuery *query;
+
+#ifndef GST_DISABLE_GST_DEBUG
+  if (!GST_CAT_CONTEXT)
+    GST_DEBUG_CATEGORY_GET (GST_CAT_CONTEXT, "GST_CONTEXT");
+#endif
+
+  query = _gst_context_query (element, context_ptr, "gst.gl.app_context");
+  gst_query_parse_context (query, &ctxt);
+  if (ctxt && gst_context_has_context_type (ctxt, "gst.gl.app_context")) {
+    const GstStructure *s = gst_context_get_structure (ctxt);
+    gst_structure_get (s, "context", GST_GL_TYPE_CONTEXT, context_ptr, NULL);
+  }
+
+  gst_query_unref (query);
+}
+
 /*  4) Create a context by itself and post a GST_MESSAGE_HAVE_CONTEXT
  *     message.
  */
@@ -705,25 +722,27 @@ gst_gl_display_context_propagate (GstElement * element, GstGLDisplay * display)
 }
 
 gboolean
-gst_gl_ensure_display (gpointer element, GstGLDisplay ** display_ptr)
+gst_gl_ensure_element_data (gpointer element, GstGLDisplay ** display_ptr,
+    GstGLContext ** context_ptr)
 {
   GstGLDisplay *display;
 
   g_return_val_if_fail (element != NULL, FALSE);
   g_return_val_if_fail (display_ptr != NULL, FALSE);
+  g_return_val_if_fail (context_ptr != NULL, FALSE);
 
   /*  1) Check if the element already has a context of the specific
    *     type.
    */
   display = *display_ptr;
   if (gst_gl_display_found (element, display))
-    return TRUE;
+    goto get_gl_context;
 
-  gst_gl_display_context_prepare (element, display_ptr);
+  gst_gl_display_context_query (element, display_ptr);
 
   /* Neighbour found and it updated the display */
   if (gst_gl_display_found (element, *display_ptr))
-    return TRUE;
+    goto get_gl_context;
 
   /* If no neighboor, or application not interested, use system default */
   display = gst_gl_display_new ();
@@ -732,17 +751,26 @@ gst_gl_ensure_display (gpointer element, GstGLDisplay ** display_ptr)
 
   gst_gl_display_context_propagate (element, display);
 
-  return display != NULL;
+get_gl_context:
+  if (*context_ptr)
+    goto done;
+
+  gst_gl_context_query (element, context_ptr);
+
+done:
+  return *display_ptr != NULL;
 }
 
 gboolean
 gst_gl_handle_set_context (GstElement * element, GstContext * context,
-    GstGLDisplay ** display)
+    GstGLDisplay ** display, GstGLContext ** other_context)
 {
-  GstGLDisplay *replacement = NULL;
+  GstGLDisplay *display_replacement = NULL;
+  GstGLContext *context_replacement = NULL;
   const gchar *context_type;
 
-  g_return_val_if_fail (display, FALSE);
+  g_return_val_if_fail (display != NULL, FALSE);
+  g_return_val_if_fail (other_context != NULL, FALSE);
 
   if (!context)
     return FALSE;
@@ -750,7 +778,7 @@ gst_gl_handle_set_context (GstElement * element, GstContext * context,
   context_type = gst_context_get_context_type (context);
 
   if (g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
-    if (!gst_context_get_gl_display (context, &replacement)) {
+    if (!gst_context_get_gl_display (context, &display_replacement)) {
       GST_WARNING_OBJECT (element, "Failed to get display from context");
       return FALSE;
     }
@@ -762,14 +790,43 @@ gst_gl_handle_set_context (GstElement * element, GstContext * context,
 
     s = gst_context_get_structure (context);
     if (gst_structure_get (s, "display", G_TYPE_POINTER, &display, NULL))
-      replacement =
+      display_replacement =
           (GstGLDisplay *) gst_gl_display_x11_new_with_display (display);
   }
 #endif
+  else if (g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
+    const GstStructure *s = gst_context_get_structure (context);
+    GstGLDisplay *context_display;
+    GstGLDisplay *element_display;
 
-  if (replacement) {
+    if (gst_structure_get (s, "context", GST_GL_TYPE_CONTEXT,
+            &context_replacement, NULL)) {
+      context_display = gst_gl_context_get_display (context_replacement);
+      element_display = display_replacement ? display_replacement : *display;
+      if (element_display
+          && (gst_gl_display_get_handle_type (element_display) &
+              gst_gl_display_get_handle_type (context_display)) == 0) {
+        GST_ELEMENT_WARNING (element, LIBRARY, SETTINGS, ("%s",
+                "Cannot set a GL context with a different display type"), ("%s",
+                "Cannot set a GL context with a different display type"));
+        gst_object_unref (context_replacement);
+        context_replacement = NULL;
+      }
+      gst_object_unref (context_display);
+    }
+  }
+
+  if (display_replacement) {
     GstGLDisplay *old = *display;
-    *display = replacement;
+    *display = display_replacement;
+
+    if (old)
+      gst_object_unref (old);
+  }
+
+  if (context_replacement) {
+    GstGLContext *old = *other_context;
+    *other_context = context_replacement;
 
     if (old)
       gst_object_unref (old);
@@ -780,7 +837,7 @@ gst_gl_handle_set_context (GstElement * element, GstContext * context,
 
 gboolean
 gst_gl_handle_context_query (GstElement * element, GstQuery * query,
-    GstGLDisplay ** display)
+    GstGLDisplay ** display, GstGLContext ** other_context)
 {
   gboolean res = FALSE;
   const gchar *context_type;
@@ -789,6 +846,7 @@ gst_gl_handle_context_query (GstElement * element, GstQuery * query,
   g_return_val_if_fail (element != NULL, FALSE);
   g_return_val_if_fail (query != NULL, FALSE);
   g_return_val_if_fail (display != NULL, FALSE);
+  g_return_val_if_fail (other_context != NULL, FALSE);
 
   gst_query_parse_context_type (query, &context_type);
 
@@ -833,6 +891,23 @@ gst_gl_handle_context_query (GstElement * element, GstQuery * query,
     res = x11_display != NULL;
   }
 #endif
+  else if (g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
+    GstStructure *s;
+
+    gst_query_parse_context (query, &old_context);
+
+    if (old_context)
+      context = gst_context_copy (old_context);
+    else
+      context = gst_context_new ("gst.gl.app_context", TRUE);
+
+    s = gst_context_writable_structure (context);
+    gst_structure_set (s, "context", GST_GL_TYPE_CONTEXT, *other_context, NULL);
+    gst_query_set_context (query, context);
+    gst_context_unref (context);
+
+    res = *other_context != NULL;
+  }
 
   return res;
 }

gst-libs/gst/gl/gstglutils.h

@@ -98,11 +98,12 @@ gboolean gst_gl_context_check_framebuffer_status (GstGLContext * context);
 void gst_gl_context_set_error (GstGLContext * context, const char * format, ...);
 gchar *gst_gl_context_get_error (void);
 
-gboolean gst_gl_ensure_display (gpointer element, GstGLDisplay **display_ptr);
+gboolean gst_gl_ensure_element_data (gpointer element,
+    GstGLDisplay **display_ptr, GstGLContext ** other_context_ptr);
 gboolean gst_gl_handle_set_context (GstElement * element, GstContext * context, 
-    GstGLDisplay ** display);
+    GstGLDisplay ** display, GstGLContext ** other_context);
 gboolean gst_gl_handle_context_query (GstElement * element, GstQuery * query, 
-    GstGLDisplay ** display);
+    GstGLDisplay ** display, GstGLContext ** other_context);
 
 G_END_DECLS