[852/906] use GstContext for GstGLDisplay propogation

implements the hooks required in GstElement::set_context and the context query

gst-libs/gst/gl/gstgldisplay.c

@@ -28,11 +28,13 @@
 #include "gl.h"
 #include "gstgldisplay.h"
 
+GST_DEBUG_CATEGORY_STATIC (gst_context);
 GST_DEBUG_CATEGORY_STATIC (gst_gl_display_debug);
 #define GST_CAT_DEFAULT gst_gl_display_debug
 
 #define DEBUG_INIT \
-  GST_DEBUG_CATEGORY_INIT (gst_gl_display_debug, "gldisplay", 0, "opengl display");
+  GST_DEBUG_CATEGORY_INIT (gst_gl_display_debug, "gldisplay", 0, "opengl display"); \
+  GST_DEBUG_CATEGORY_GET (gst_context, "GST_CONTEXT");
 
 G_DEFINE_TYPE_WITH_CODE (GstGLDisplay, gst_gl_display, G_TYPE_OBJECT,
     DEBUG_INIT);
@@ -66,6 +68,8 @@ gst_gl_display_init (GstGLDisplay * display)
 
   display->gl_api = GST_GL_API_NONE;
 
+  GST_TRACE ("init %p", display);
+
   gst_gl_memory_init ();
 }
 
@@ -79,6 +83,8 @@ gst_gl_display_finalize (GObject * object)
     display->context = NULL;
   }
 
+  GST_TRACE ("finalize %p", object);
+
   G_OBJECT_CLASS (gst_gl_display_parent_class)->finalize (object);
 }
 
@@ -142,6 +148,11 @@ gst_context_set_gl_display (GstContext * context, GstGLDisplay * display)
 {
   GstStructure *s;
 
+  g_return_if_fail (context != NULL);
+
+  GST_CAT_LOG (gst_context, "setting GstGLDisplay(%p) on context(%p)", display,
+      context);
+
   s = gst_context_writable_structure (context);
   gst_structure_set (s, GST_GL_DISPLAY_CONTEXT_TYPE, GST_TYPE_GL_DISPLAY,
       display, NULL);
@@ -151,8 +162,17 @@ gboolean
 gst_context_get_gl_display (GstContext * context, GstGLDisplay ** display)
 {
   const GstStructure *s;
+  gboolean ret;
+
+  g_return_val_if_fail (display != NULL, FALSE);
+  g_return_val_if_fail (context != NULL, FALSE);
 
   s = gst_context_get_structure (context);
-  return gst_structure_get (s, GST_GL_DISPLAY_CONTEXT_TYPE,
+  ret = gst_structure_get (s, GST_GL_DISPLAY_CONTEXT_TYPE,
       GST_TYPE_GL_DISPLAY, display, NULL);
+
+  GST_CAT_LOG (gst_context, "got GstGLDisplay(%p) from context(%p)", *display,
+      context);
+
+  return ret;
 }

gst-libs/gst/gl/gstglfilter.c

@@ -62,6 +62,8 @@ static void gst_gl_filter_set_property (GObject * object, guint prop_id,
 static void gst_gl_filter_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);
 
+static void gst_gl_filter_set_context (GstElement * element,
+    GstContext * context);
 static gboolean gst_gl_filter_query (GstBaseTransform * trans,
     GstPadDirection direction, GstQuery * query);
 static GstCaps *gst_gl_filter_transform_caps (GstBaseTransform * bt,
@@ -112,6 +114,8 @@ gst_gl_filter_class_init (GstGLFilterClass * klass)
       gst_gl_filter_decide_allocation;
   GST_BASE_TRANSFORM_CLASS (klass)->get_unit_size = gst_gl_filter_get_unit_size;
 
+  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",
@@ -176,6 +180,14 @@ gst_gl_filter_get_property (GObject * object, guint prop_id,
   }
 }
 
+static void
+gst_gl_filter_set_context (GstElement * element, GstContext * context)
+{
+  GstGLFilter *filter = GST_GL_FILTER (element);
+
+  gst_gl_handle_set_context (element, context, &filter->display);
+}
+
 static gboolean
 gst_gl_filter_query (GstBaseTransform * trans, GstPadDirection direction,
     GstQuery * query)
@@ -186,13 +198,19 @@ gst_gl_filter_query (GstBaseTransform * trans, GstPadDirection direction,
   filter = GST_GL_FILTER (trans);
 
   switch (GST_QUERY_TYPE (query)) {
+    case GST_QUERY_CONTEXT:
+    {
+      res = gst_gl_handle_context_query ((GstElement *) filter, query,
+          &filter->display);
+      break;
+    }
     case GST_QUERY_CUSTOM:
     {
       GstStructure *structure = gst_query_writable_structure (query);
       if (direction == GST_PAD_SINK &&
-          gst_structure_has_name (structure, "gstgldisplay")) {
+          gst_structure_has_name (structure, "gstglcontext")) {
-        gst_structure_set (structure, "gstgldisplay", G_TYPE_POINTER,
+        gst_structure_set (structure, "gstglcontext", G_TYPE_POINTER,
-            filter->display, NULL);
+            filter->context, NULL);
         res = TRUE;
       } else
         res =
@@ -243,6 +261,10 @@ gst_gl_filter_reset (GstGLFilter * filter)
   if (filter->other_context)
     gst_object_unref (filter->other_context);
   filter->other_context = NULL;
+
+  if (filter->context)
+    gst_object_unref (filter->context);
+  filter->context = NULL;
 }
 
 static gboolean
@@ -251,28 +273,29 @@ gst_gl_filter_start (GstBaseTransform * bt)
   GstGLFilter *filter = GST_GL_FILTER (bt);
   GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (filter);
   GstStructure *structure;
-  GstQuery *display_query;
+  GstQuery *context_query;
   const GValue *id_value;
 
-  structure = gst_structure_new_empty ("gstgldisplay");
+  if (!gst_gl_ensure_display (filter, &filter->display))
-  display_query = gst_query_new_custom (GST_QUERY_CUSTOM, structure);
+    return FALSE;
 
-  if (!gst_pad_peer_query (bt->srcpad, display_query)) {
+  structure = gst_structure_new_empty ("gstglcontext");
+  context_query = gst_query_new_custom (GST_QUERY_CUSTOM, structure);
+
+  if (!gst_pad_peer_query (bt->srcpad, context_query)) {
     GST_WARNING
-        ("Could not query GstGLDisplay from downstream (peer query failed)");
+        ("Could not query GstGLContext from downstream (peer query failed)");
   }
 
-  id_value = gst_structure_get_value (structure, "gstgldisplay");
+  id_value = gst_structure_get_value (structure, "gstglcontext");
   if (G_VALUE_HOLDS_POINTER (id_value)) {
     /* at least one gl element is after in our gl chain */
-    filter->display =
+    filter->context =
-        gst_object_ref (GST_GL_DISPLAY (g_value_get_pointer (id_value)));
+        gst_object_ref (GST_GL_CONTEXT (g_value_get_pointer (id_value)));
-    filter->context = gst_gl_display_get_context (filter->display);
   } else {
     GError *error = NULL;
 
-    GST_INFO ("Creating GstGLDisplay");
+    GST_INFO ("Creating GstGLContext");
-    filter->display = gst_gl_display_new ();
     filter->context = gst_gl_context_new (filter->display);
 
     if (!gst_gl_context_create (filter->context, filter->other_context, &error)) {
@@ -282,6 +305,8 @@ gst_gl_filter_start (GstBaseTransform * bt)
     }
   }
 
+  gst_query_unref (context_query);
+
   if (filter_class->onStart)
     filter_class->onStart (filter);
 
@@ -1067,6 +1092,9 @@ 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))
+    return GST_FLOW_NOT_NEGOTIATED;
+
   g_assert (filter_class->filter || filter_class->filter_texture);
 
   if (filter_class->filter)

gst-libs/gst/gl/gstglfilter.h

@@ -65,7 +65,6 @@ struct _GstGLFilter
   GstBufferPool     *pool;
 
   GstGLDisplay      *display;
-  GstGLContext      *context;
 
   GstVideoInfo       in_info;
   GstVideoInfo       out_info;
@@ -81,6 +80,7 @@ struct _GstGLFilter
 
   GstGLShader       *default_shader;
 
+  GstGLContext      *context;
   GstGLContext      *other_context;
 };
 

gst-libs/gst/gl/gstglmixer.c

@@ -60,6 +60,8 @@ static gboolean gst_gl_mixer_sink_event (GstCollectPads * pads,
     GstCollectData * cdata, GstEvent * event, GstGLMixer * mix);
 static gboolean gst_gl_mixer_src_setcaps (GstPad * pad, GstGLMixer * mix,
     GstCaps * caps);
+static void gst_gl_mixer_set_context (GstElement * element,
+    GstContext * context);
 
 enum
 {
@@ -346,15 +348,21 @@ gst_gl_mixer_sink_query (GstCollectPads * pads, GstCollectData * data,
       ret = TRUE;
       break;
     }
+    case GST_QUERY_CONTEXT:
+    {
+      ret = gst_gl_handle_context_query ((GstElement *) mix, query,
+          &mix->display);
+      break;
+    }
     case GST_QUERY_CUSTOM:
     {
       /* mix is a sink in terms of gl chain, so we are sharing the gldisplay that
        * comes from src pad with every display of the sink pads */
       GstStructure *structure = gst_query_writable_structure (query);
 
-      if (gst_structure_has_name (structure, "gstgldisplay")) {
+      if (gst_structure_has_name (structure, "gstglcontext")) {
-        gst_structure_set (structure, "gstgldisplay", G_TYPE_POINTER,
+        gst_structure_set (structure, "gstglcontext", G_TYPE_POINTER,
-            mix->display, NULL);
+            mix->context, NULL);
       } else {
         ret = gst_collect_pads_query_default (pads, data, query, FALSE);
       }
@@ -513,6 +521,7 @@ gst_gl_mixer_class_init (GstGLMixerClass * klass)
       GST_DEBUG_FUNCPTR (gst_gl_mixer_request_new_pad);
   element_class->release_pad = GST_DEBUG_FUNCPTR (gst_gl_mixer_release_pad);
   element_class->change_state = GST_DEBUG_FUNCPTR (gst_gl_mixer_change_state);
+  element_class->set_context = GST_DEBUG_FUNCPTR (gst_gl_mixer_set_context);
 
   /* Register the pad class */
   g_type_class_ref (GST_TYPE_GL_MIXER_PAD);
@@ -845,6 +854,14 @@ gst_gl_mixer_read_qos (GstGLMixer * mix, gdouble * proportion,
   GST_OBJECT_UNLOCK (mix);
 }
 
+static void
+gst_gl_mixer_set_context (GstElement * element, GstContext * context)
+{
+  GstGLMixer *mix = GST_GL_MIXER (element);
+
+  gst_gl_handle_set_context (element, context, &mix->display);
+}
+
 static gboolean
 gst_gl_mixer_src_query (GstPad * pad, GstObject * parent, GstQuery * query)
 {
@@ -852,6 +869,12 @@ gst_gl_mixer_src_query (GstPad * pad, GstObject * parent, GstQuery * query)
   gboolean res = FALSE;
 
   switch (GST_QUERY_TYPE (query)) {
+    case GST_QUERY_CONTEXT:
+    {
+      res = gst_gl_handle_context_query ((GstElement *) mix, query,
+          &mix->display);
+      break;
+    }
     case GST_QUERY_POSITION:
     {
       GstFormat format;
@@ -918,27 +941,29 @@ gst_gl_mixer_activate (GstGLMixer * mix, gboolean activate)
 {
   if (activate) {
     GstStructure *structure;
-    GstQuery *display_query;
+    GstQuery *context_query;
     const GValue *id_value;
 
-    structure = gst_structure_new_empty ("gstgldisplay");
+    if (!gst_gl_ensure_display (mix, &mix->display)) {
-    display_query = gst_query_new_custom (GST_QUERY_CUSTOM, structure);
+      return FALSE;
-
-    if (!gst_pad_peer_query (mix->srcpad, display_query)) {
-      GST_WARNING
-          ("Could not query GstGLDisplay from downstream (peer query failed)");
     }
 
-    id_value = gst_structure_get_value (structure, "gstgldisplay");
+    structure = gst_structure_new_empty ("gstglcontext");
+    context_query = gst_query_new_custom (GST_QUERY_CUSTOM, structure);
+
+    if (!gst_pad_peer_query (mix->srcpad, context_query)) {
+      GST_WARNING
+          ("Could not query GstGLContext from downstream (peer query failed)");
+    }
+
+    id_value = gst_structure_get_value (structure, "gstglcontext");
     if (G_VALUE_HOLDS_POINTER (id_value)) {
-      mix->display =
+      mix->context =
-          gst_object_ref (GST_GL_DISPLAY (g_value_get_pointer (id_value)));
+          gst_object_ref (GST_GL_CONTEXT (g_value_get_pointer (id_value)));
-      mix->context = gst_gl_display_get_context (mix->display);
     } else {
       GError *error = NULL;
 
       GST_INFO ("Creating GstGLDisplay");
-      mix->display = gst_gl_display_new ();
       mix->context = gst_gl_context_new (mix->display);
       gst_gl_display_set_context (mix->display, mix->context);
 

gst-libs/gst/gl/gstglutils.c

@@ -365,3 +365,227 @@ gst_gl_context_del_shader (GstGLContext * context, GstGLShader * shader)
 {
   gst_object_unref (shader);
 }
+
+static gboolean
+gst_gl_display_found (GstElement * element, GstGLDisplay * display)
+{
+  if (display) {
+    GST_INFO_OBJECT (element, "already have a display (%p)", display);
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_CONTEXT);
+
+static gboolean
+context_pad_query (const GValue * item, GValue * value, gpointer user_data)
+{
+  GstPad *pad = g_value_get_object (item);
+  GstQuery *query = user_data;
+  gboolean res;
+
+  res = gst_pad_peer_query (pad, query);
+
+  if (res) {
+    g_value_set_boolean (value, TRUE);
+    return FALSE;
+  }
+
+  GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, pad, "context pad peer query failed");
+  return TRUE;
+}
+
+static gboolean
+run_context_query (GstElement * element, GstQuery * query,
+    GstPadDirection direction)
+{
+  GstIterator *it;
+  GstIteratorFoldFunction func = context_pad_query;
+  GValue res = { 0 };
+
+  g_value_init (&res, G_TYPE_BOOLEAN);
+  g_value_set_boolean (&res, FALSE);
+
+  /* Ask neighbor */
+  if (direction == GST_PAD_SRC)
+    it = gst_element_iterate_src_pads (element);
+  else
+    it = gst_element_iterate_sink_pads (element);
+
+  while (gst_iterator_fold (it, func, &res, query) == GST_ITERATOR_RESYNC)
+    gst_iterator_resync (it);
+
+  gst_iterator_free (it);
+
+  return g_value_get_boolean (&res);
+}
+
+static void
+gst_gl_display_context_prepare (GstElement * element,
+    GstGLDisplay ** display_ptr)
+{
+  GstContext *ctxt;
+  GstQuery *query;
+
+  if (!GST_CAT_CONTEXT)
+    GST_DEBUG_CATEGORY_GET (GST_CAT_CONTEXT, "GST_CONTEXT");
+
+  /*  2a) Query downstream with GST_QUERY_CONTEXT for the context and
+   *      check if downstream already has a context of the specific type
+   *  2b) Query upstream as above.
+   */
+  ctxt = NULL;
+  query = gst_query_new_context (GST_GL_DISPLAY_CONTEXT_TYPE);
+  if (run_context_query (element, query, GST_PAD_SRC)) {
+    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
+        "found context (%p) in downstream query", ctxt);
+    gst_query_parse_context (query, &ctxt);
+  } else if (run_context_query (element, query, GST_PAD_SINK)) {
+    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
+        "found context (%p) in upstream query", ctxt);
+    gst_query_parse_context (query, &ctxt);
+  } else {
+    /* 3) Post a GST_MESSAGE_NEED_CONTEXT message on the bus with
+     *    the required context type and afterwards check if a
+     *    usable context was set now as in 1). The message could
+     *    be handled by the parent bins of the element and the
+     *    application.
+     */
+    GstMessage *msg;
+
+    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
+        "posting need context message");
+    msg = gst_message_new_need_context (GST_OBJECT_CAST (element),
+        GST_GL_DISPLAY_CONTEXT_TYPE);
+    gst_element_post_message (element, msg);
+  }
+
+  /*
+   * Whomever responds to the need-context message performs a
+   * GstElement::set_context() with the required context in which the element
+   * is required to update the display_ptr or call gst_gl_handle_set_context().
+   */
+  if (ctxt) {
+    if (gst_context_has_context_type (ctxt, GST_GL_DISPLAY_CONTEXT_TYPE)) {
+      gst_context_get_gl_display (ctxt, display_ptr);
+    }
+  }
+
+  gst_query_unref (query);
+}
+
+/*  4) Create a context by itself and post a GST_MESSAGE_HAVE_CONTEXT
+ *     message.
+ */
+static void
+gst_gl_display_context_propagate (GstElement * element, GstGLDisplay * display)
+{
+  GstContext *context;
+  GstMessage *msg;
+
+  if (!display) {
+    GST_ERROR_OBJECT (element, "Could not get GL display connection");
+    return;
+  }
+
+  context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
+  gst_context_set_gl_display (context, display);
+
+  GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
+      "posting have context (%p) message with display (%p)", context, display);
+  msg = gst_message_new_have_context (GST_OBJECT_CAST (element), context);
+  gst_element_post_message (GST_ELEMENT_CAST (element), msg);
+}
+
+gboolean
+gst_gl_ensure_display (gpointer element, GstGLDisplay ** display_ptr)
+{
+  GstGLDisplay *display;
+
+  g_return_val_if_fail (element != NULL, FALSE);
+  g_return_val_if_fail (display_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;
+
+  gst_gl_display_context_prepare (element, display_ptr);
+
+  /* Neighbour found and it updated the display */
+  if (gst_gl_display_found (element, *display_ptr))
+    return TRUE;
+
+  /* If no neighboor, or application not interested, use system default */
+  display = gst_gl_display_new ();
+
+  *display_ptr = display;
+
+  gst_gl_display_context_propagate (element, display);
+
+  return display != NULL;
+}
+
+gboolean
+gst_gl_handle_set_context (GstElement * element, GstContext * context,
+    GstGLDisplay ** display)
+{
+  GstGLDisplay *replacement = NULL;
+  const gchar *context_type;
+
+  g_return_val_if_fail (display, FALSE);
+
+  if (!context)
+    return FALSE;
+
+  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)) {
+      GST_WARNING_OBJECT (element, "Failed to get display from context");
+      return FALSE;
+    }
+  }
+
+  if (replacement)
+    gst_object_replace ((GstObject **) display, (GstObject *) replacement);
+
+  return TRUE;
+}
+
+gboolean
+gst_gl_handle_context_query (GstElement * element, GstQuery * query,
+    GstGLDisplay ** display)
+{
+  gboolean res = FALSE;
+  const gchar *context_type;
+  GstContext *context, *old_context;
+
+  g_return_val_if_fail (element != NULL, FALSE);
+  g_return_val_if_fail (query != NULL, FALSE);
+  g_return_val_if_fail (display != NULL, FALSE);
+
+  gst_query_parse_context_type (query, &context_type);
+
+  if (g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
+
+    gst_query_parse_context (query, &old_context);
+
+    if (old_context)
+      context = gst_context_copy (old_context);
+    else
+      context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
+
+    gst_context_set_gl_display (context, *display);
+    gst_query_set_context (query, context);
+    gst_context_unref (context);
+
+    res = *display != NULL;
+  }
+
+  return res;
+}

gst-libs/gst/gl/gstglutils.h

@@ -102,4 +102,10 @@ 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_handle_set_context (GstElement * element, GstContext * context, 
+    GstGLDisplay ** display);
+gboolean gst_gl_handle_context_query (GstElement * element, GstQuery * query, 
+    GstGLDisplay ** display);
+
 #endif /* __GST_GL_UTILS_H__ */