gldisplay: implement runtime GL api filtering

Needed so that the pipeline/application can limit the choice of GL api
to what it supports

docs/libs/gst-plugins-bad-libs-sections.txt

@@ -899,6 +899,8 @@ GstGLDisplayType
 GstGLDisplay
 gst_gl_display_new
 gst_gl_display_get_handle_type
+gst_gl_display_filter_gl_api
+gst_gl_display_get_gl_api
 gst_context_get_gl_display
 gst_context_set_gl_display
 <SUBSECTION Standard>

ext/gl/gstglbumper.c

@@ -296,6 +296,8 @@ gst_gl_bumper_class_init (GstGLBumperClass * klass)
       "Filter/Effect/Video", "Bump mapping filter",
       "Cyril Comparon <cyril.comparon@gmail.com>, "
       "Julien Isorce <julien.isorce@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglcolorscale.c

@@ -104,6 +104,8 @@ gst_gl_colorscale_class_init (GstGLColorscaleClass * klass)
   filter_class->filter_texture = gst_gl_colorscale_filter_texture;
 
   basetransform_class->passthrough_on_same_caps = TRUE;
+  filter_class->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_OPENGL3 | GST_GL_API_GLES2;
 }
 
 static void

ext/gl/gstgldeinterlace.c

@@ -168,6 +168,8 @@ gst_gl_deinterlace_class_init (GstGLDeinterlaceClass * klass)
       gst_gl_deinterlace_filter_texture;
   GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_deinterlace_init_shader;
   GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_deinterlace_reset;
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstgldifferencematte.c

@@ -193,6 +193,8 @@ gst_gl_differencematte_class_init (GstGLDifferenceMatteClass * klass)
       "Gstreamer OpenGL DifferenceMatte", "Filter/Effect/Video",
       "Saves a background frame and replace it with a pixbuf",
       "Filippo Argiolas <filippo.argiolas@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstgleffects.c

@@ -130,56 +130,91 @@ gst_gl_effects_effect_get_type (void)
 static void
 gst_gl_effects_set_effect (GstGLEffects * effects, gint effect_type)
 {
+  GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (effects);
+  GstGLContext *context = GST_GL_FILTER (effects)->context;
 
   switch (effect_type) {
     case GST_GL_EFFECT_IDENTITY:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_identity;
+      filter_class->supported_gl_api =
+          GST_GL_API_GLES2 | GST_GL_API_OPENGL | GST_GL_API_OPENGL3;
+      effects->current_effect = effect_type;
       break;
     case GST_GL_EFFECT_MIRROR:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_mirror;
+      filter_class->supported_gl_api =
+          GST_GL_API_GLES2 | GST_GL_API_OPENGL | GST_GL_API_OPENGL3;
+      effects->current_effect = effect_type;
       break;
     case GST_GL_EFFECT_SQUEEZE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_squeeze;
+      filter_class->supported_gl_api =
+          GST_GL_API_GLES2 | GST_GL_API_OPENGL | GST_GL_API_OPENGL3;
+      effects->current_effect = effect_type;
       break;
+  }
+
+  if (context
+      && (gst_gl_context_get_gl_api (context) & GST_GL_API_OPENGL) ==
+      GST_GL_API_NONE) {
+    GST_ELEMENT_WARNING (effects, RESOURCE, SETTINGS, ("%s",
+            "cannot change effect type"), ("%s",
+            "the current OpenGL context does not support the GL API required"));
+    return;
+  }
 #if GST_GL_HAVE_OPENGL
+  switch (effect_type) {
     case GST_GL_EFFECT_STRETCH:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_stretch;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_TUNNEL:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_tunnel;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_FISHEYE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_fisheye;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_TWIRL:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_twirl;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_BULGE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_bulge;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_SQUARE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_square;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_HEAT:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_heat;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_SEPIA:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sepia;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_XPRO:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_xpro;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_LUMA_XPRO:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_luma_xpro;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_XRAY:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_xray;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_SIN:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
     case GST_GL_EFFECT_GLOW:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_glow;
+      filter_class->supported_gl_api = GST_GL_API_OPENGL;
       break;
 #endif
     default:
@@ -273,6 +308,9 @@ gst_gl_effects_class_init (GstGLEffectsClass * klass)
       "Gstreamer OpenGL Effects", "Filter/Effect/Video",
       "GL Shading Language effects",
       "Filippo Argiolas <filippo.argiolas@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }
 
 static void

ext/gl/gstglfilterapp.c

@@ -111,6 +111,9 @@ gst_gl_filter_app_class_init (GstGLFilterAppClass * klass)
       "OpenGL application filter", "Filter/Effect",
       "Use client callbacks to define the scene",
       "Julien Isorce <julien.isorce@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }
 
 static void

ext/gl/gstglfilterblur.c

@@ -114,6 +114,8 @@ gst_gl_filterblur_class_init (GstGLFilterBlurClass * klass)
       gst_gl_filterblur_reset_resources;
   GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_filterblur_init_shader;
   GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_filter_filterblur_reset;
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglfiltercube.c

@@ -179,6 +179,9 @@ gst_gl_filter_cube_class_init (GstGLFilterCubeClass * klass)
   gst_element_class_set_metadata (element_class, "OpenGL cube filter",
       "Filter/Effect/Video", "Map input texture on the 6 cube faces",
       "Julien Isorce <julien.isorce@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }
 
 static void

ext/gl/gstglfilterglass.c

@@ -162,6 +162,8 @@ gst_gl_filter_glass_class_init (GstGLFilterGlassClass * klass)
       gst_gl_filter_glass_filter_texture;
   GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_filter_glass_init_shader;
   GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_filter_glass_reset;
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglfilterlaplacian.c

@@ -119,6 +119,8 @@ gst_gl_filter_laplacian_class_init (GstGLFilterLaplacianClass * klass)
       gst_gl_filter_laplacian_filter_texture;
   GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_filter_laplacian_init_shader;
   GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_filter_laplacian_reset;
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglfilterreflectedscreen.c

@@ -138,6 +138,8 @@ gst_gl_filter_reflected_screen_class_init (GstGLFilterReflectedScreenClass *
   gst_element_class_set_metadata (element_class,
       "OpenGL Reflected Screen filter", "Filter/Effect/Video",
       "Reflected Screen Filter", "Pierre POUZOL <pierre.pouzol@hotmail.fr>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglfiltershader.c

@@ -149,6 +149,9 @@ gst_gl_filtershader_class_init (GstGLFilterShaderClass * klass)
       gst_gl_filtershader_reset_resources;
   GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_filtershader_init_shader;
   GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_filter_filtershader_reset;
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }
 
 static void

ext/gl/gstglfiltersobel.c

@@ -131,6 +131,8 @@ gst_gl_filtersobel_class_init (GstGLFilterSobelClass * klass)
   gst_element_class_set_metadata (element_class,
       "Gstreamer OpenGL Sobel", "Filter/Effect/Video", "Sobel edge detection",
       "Filippo Argiolas <filippo.argiolas@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstglimagesink.c

@@ -111,6 +111,8 @@ GST_DEBUG_CATEGORY (gst_debug_glimage_sink);
 #define USING_GLES2(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 2, 0))
 #define USING_GLES3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 3, 0))
 
+#define SUPPORTED_GL_APIS GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3
+
 static void gst_glimage_sink_thread_init_redisplay (GstGLImageSink * gl_sink);
 static void gst_glimage_sink_cleanup_glthread (GstGLImageSink * gl_sink);
 static void gst_glimage_sink_on_close (GstGLImageSink * gl_sink);
@@ -493,6 +495,8 @@ _ensure_gl_setup (GstGLImageSink * gl_sink)
           &gl_sink->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (gl_sink->display, SUPPORTED_GL_APIS);
+
   if (!gl_sink->context) {
     GstGLWindow *window;
 
@@ -564,8 +568,12 @@ gst_glimage_sink_query (GstBaseSink * bsink, GstQuery * query)
   switch (GST_QUERY_TYPE (query)) {
     case GST_QUERY_CONTEXT:
     {
-      return gst_gl_handle_context_query ((GstElement *) glimage_sink, query,
+      gboolean ret =
+          gst_gl_handle_context_query ((GstElement *) glimage_sink, query,
           &glimage_sink->display, &glimage_sink->other_context);
+      if (glimage_sink->display)
+        gst_gl_display_filter_gl_api (glimage_sink->display, SUPPORTED_GL_APIS);
+      return ret;
     }
     case GST_QUERY_DRAIN:
     {
@@ -619,6 +627,9 @@ gst_glimage_sink_set_context (GstElement * element, GstContext * context)
 
   gst_gl_handle_set_context (element, context, &gl_sink->display,
       &gl_sink->other_context);
+
+  if (gl_sink->display)
+    gst_gl_display_filter_gl_api (gl_sink->display, SUPPORTED_GL_APIS);
 }
 
 static GstStateChangeReturn
@@ -638,11 +649,6 @@ gst_glimage_sink_change_state (GstElement * element, GstStateChange transition)
       break;
     case GST_STATE_CHANGE_READY_TO_PAUSED:
       g_atomic_int_set (&glimage_sink->to_quit, 0);
-      if (!glimage_sink->display) {
-        if (!gst_gl_ensure_element_data (glimage_sink, &glimage_sink->display,
-                &glimage_sink->other_context))
-          return GST_STATE_CHANGE_FAILURE;
-      }
       break;
     case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
       break;

ext/gl/gstglmixer.c

@@ -152,6 +152,7 @@ static gboolean
 gst_gl_mixer_propose_allocation (GstGLMixer * mix,
     GstQuery * decide_query, GstQuery * query)
 {
+  GstGLMixerClass *mix_class = GST_GL_MIXER_GET_CLASS (mix);
   GstBufferPool *pool;
   GstStructure *config;
   GstCaps *caps;
@@ -192,6 +193,8 @@ gst_gl_mixer_propose_allocation (GstGLMixer * mix,
   if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
+
   if (!mix->context) {
     mix->context = gst_gl_context_new (mix->display);
     if (!gst_gl_context_create (mix->context, mix->other_context, &error))
@@ -428,6 +431,7 @@ gst_gl_mixer_sink_query (GstAggregator * agg, GstAggregatorPad * bpad,
 {
   gboolean ret = FALSE;
   GstGLMixer *mix = GST_GL_MIXER (agg);
+  GstGLMixerClass *mix_class = GST_GL_MIXER_GET_CLASS (mix);
 
   GST_TRACE ("QUERY %" GST_PTR_FORMAT, query);
 
@@ -485,6 +489,9 @@ gst_gl_mixer_sink_query (GstAggregator * agg, GstAggregatorPad * bpad,
     {
       ret = gst_gl_handle_context_query ((GstElement *) mix, query,
           &mix->display, &mix->other_context);
+      if (mix->display)
+        gst_gl_display_filter_gl_api (mix->display,
+            mix_class->supported_gl_api);
       break;
     }
     default:
@@ -615,7 +622,7 @@ gst_gl_mixer_class_init (GstGLMixerClass * klass)
   g_type_class_ref (GST_TYPE_GL_MIXER_PAD);
 
   klass->set_caps = NULL;
-
+  klass->supported_gl_api = GST_GL_API_ANY;
 }
 
 static void
@@ -661,19 +668,26 @@ static void
 gst_gl_mixer_set_context (GstElement * element, GstContext * context)
 {
   GstGLMixer *mix = GST_GL_MIXER (element);
+  GstGLMixerClass *mix_class = GST_GL_MIXER_GET_CLASS (mix);
 
   gst_gl_handle_set_context (element, context, &mix->display,
       &mix->other_context);
+
+  if (mix->display)
+    gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
 }
 
 static gboolean
 gst_gl_mixer_activate (GstGLMixer * mix, gboolean active)
 {
+  GstGLMixerClass *mix_class = GST_GL_MIXER_GET_CLASS (mix);
   gboolean result = TRUE;
 
   if (active) {
     if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
-      result = FALSE;
+      return FALSE;
+
+    gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
   }
 
   return result;
@@ -729,12 +743,16 @@ gst_gl_mixer_src_query (GstAggregator * agg, GstQuery * query)
 {
   gboolean res = FALSE;
   GstGLMixer *mix = GST_GL_MIXER (agg);
+  GstGLMixerClass *mix_class = GST_GL_MIXER_GET_CLASS (mix);
 
   switch (GST_QUERY_TYPE (query)) {
     case GST_QUERY_CONTEXT:
     {
       res = gst_gl_handle_context_query ((GstElement *) mix, query,
           &mix->display, &mix->other_context);
+      if (mix->display)
+        gst_gl_display_filter_gl_api (mix->display,
+            mix_class->supported_gl_api);
       break;
     }
     case GST_QUERY_CAPS:
@@ -785,6 +803,8 @@ gst_gl_mixer_decide_allocation (GstGLMixer * mix, GstQuery * query)
   if (!gst_gl_ensure_element_data (mix, &mix->display, &mix->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (mix->display, mixer_class->supported_gl_api);
+
   if (gst_query_find_allocation_meta (query,
           GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE, &idx)) {
     GstGLContext *context;

ext/gl/gstglmixer.h

@@ -76,6 +76,7 @@ struct _GstGLMixer
 struct _GstGLMixerClass
 {
   GstVideoAggregatorClass parent_class;
+  GstGLAPI supported_gl_api;
 
   GstGLMixerSetCaps set_caps;
   GstGLMixerReset reset;

ext/gl/gstglmosaic.c

@@ -134,6 +134,8 @@ gst_gl_mosaic_class_init (GstGLMosaicClass * klass)
   GST_GL_MIXER_CLASS (klass)->set_caps = gst_gl_mosaic_init_shader;
   GST_GL_MIXER_CLASS (klass)->reset = gst_gl_mosaic_reset;
   GST_GL_MIXER_CLASS (klass)->process_textures = gst_gl_mosaic_process_textures;
+
+  GST_GL_MIXER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL;
 }
 
 static void

ext/gl/gstgloverlay.c

@@ -244,6 +244,9 @@ gst_gl_overlay_class_init (GstGLOverlayClass * klass)
       "Overlay GL video texture with a JPEG/PNG image",
       "Filippo Argiolas <filippo.argiolas@gmail.com>, "
       "Matthew Waters <matthew@centricular.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }
 
 static void

ext/gl/gstgltestsrc.c

@@ -52,6 +52,7 @@
 #endif
 
 #define USE_PEER_BUFFERALLOC
+#define SUPPORTED_GL_APIS GST_GL_API_OPENGL
 
 GST_DEBUG_CATEGORY_STATIC (gl_test_src_debug);
 #define GST_CAT_DEFAULT gl_test_src_debug
@@ -474,7 +475,11 @@ 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, &src->other_context);
+  gst_gl_handle_set_context (element, context, &src->display,
+      &src->other_context);
+
+  if (src->display)
+    gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
 }
 
 static gboolean
@@ -490,6 +495,8 @@ gst_gl_test_src_query (GstBaseSrc * bsrc, GstQuery * query)
     {
       res = gst_gl_handle_context_query ((GstElement *) src, query,
           &src->display, &src->other_context);
+      if (src->display)
+        gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
       break;
     }
     case GST_QUERY_CONVERT:
@@ -706,6 +713,8 @@ gst_gl_test_src_start (GstBaseSrc * basesrc)
   if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
+
   src->running_time = 0;
   src->n_frames = 0;
   src->negotiated = FALSE;
@@ -766,6 +775,8 @@ gst_gl_test_src_decide_allocation (GstBaseSrc * basesrc, GstQuery * query)
   if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
+
   if (gst_query_find_allocation_meta (query,
           GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE, &idx)) {
     GstGLContext *context;

ext/gl/gstgltransformation.c

@@ -203,6 +203,9 @@ gst_gl_transformation_class_init (GstGLTransformationClass * klass)
   gst_element_class_set_metadata (element_class, "OpenGL transformation filter",
       "Filter/Effect/Video", "Transform video on the GPU",
       "Lubosz Sarnecki <lubosz@gmail.com>");
+
+  GST_GL_FILTER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_OPENGL3 | GST_GL_API_GLES2;
 }
 
 static void

ext/gl/gstglvideomixer.c

@@ -345,6 +345,9 @@ gst_gl_video_mixer_class_init (GstGLVideoMixerClass * klass)
   vagg_class->update_caps = _update_caps;
 
   agg_class->sinkpads_type = GST_TYPE_GL_VIDEO_MIXER_PAD;
+
+  GST_GL_MIXER_CLASS (klass)->supported_gl_api =
+      GST_GL_API_OPENGL | GST_GL_API_OPENGL3 | GST_GL_API_GLES2;
 }
 
 static void

gst-libs/gst/gl/gstglcontext.c

@@ -330,9 +330,14 @@ gst_gl_context_new_wrapped (GstGLDisplay * display, guintptr handle,
   GstGLContext *context;
   GstGLWrappedContext *context_wrap = NULL;
   GstGLContextClass *context_class;
+  GstGLAPI display_api;
 
   _init_debug ();
 
+  display_api = gst_gl_display_get_gl_api (display);
+  g_return_val_if_fail ((display_api & available_apis) != GST_GL_API_NONE,
+      NULL);
+
   context_wrap = g_object_new (GST_GL_TYPE_WRAPPED_CONTEXT, NULL);
 
   if (!context_wrap) {
@@ -1164,10 +1169,11 @@ gst_gl_context_create_thread (GstGLContext * context)
   GstGLWindowClass *window_class;
   GstGLFuncs *gl;
   gboolean ret = FALSE;
-  GstGLAPI compiled_api, user_api, gl_api;
+  GstGLAPI compiled_api, user_api, gl_api, display_api;
   gchar *api_string;
   gchar *compiled_api_s;
-  gchar *user_api_string;
+  gchar *user_api_s;
+  gchar *display_api_s;
   const gchar *user_choice;
   GError **error;
   GstGLContext *other_context;
@@ -1182,6 +1188,14 @@ gst_gl_context_create_thread (GstGLContext * context)
   context_class = GST_GL_CONTEXT_GET_CLASS (context);
   window_class = GST_GL_WINDOW_GET_CLASS (context->window);
 
+  display_api = gst_gl_display_get_gl_api (context->priv->display);
+  if (display_api == GST_GL_API_NONE) {
+    g_set_error (error, GST_GL_CONTEXT_ERROR, GST_GL_CONTEXT_ERROR_WRONG_API,
+        "Cannot create context with satisfying requested apis "
+        "(display has no GL api!)");
+    goto failure;
+  }
+
   if (window_class->open) {
     if (!window_class->open (context->window, error)) {
       g_assert (error == NULL || *error != NULL);
@@ -1191,20 +1205,22 @@ gst_gl_context_create_thread (GstGLContext * context)
 
   gl = context->gl_vtable;
   compiled_api = _compiled_api ();
-
-  user_choice = g_getenv ("GST_GL_API");
-
-  user_api = gst_gl_api_from_string (user_choice);
-  user_api_string = gst_gl_api_to_string (user_api);
-
   compiled_api_s = gst_gl_api_to_string (compiled_api);
 
-  if ((user_api & compiled_api) == GST_GL_API_NONE) {
+  user_choice = g_getenv ("GST_GL_API");
+  user_api = gst_gl_api_from_string (user_choice);
+  user_api_s = gst_gl_api_to_string (user_api);
+
+  display_api_s = gst_gl_api_to_string (display_api);
+
+  if ((user_api & compiled_api & display_api) == GST_GL_API_NONE) {
     g_set_error (error, GST_GL_CONTEXT_ERROR, GST_GL_CONTEXT_ERROR_WRONG_API,
         "Cannot create context with the user requested api (%s).  "
-        "We have support for (%s)", user_api_string, compiled_api_s);
+        "We have support for (%s), display api (%s)", user_api_s,
-    g_free (user_api_string);
+        compiled_api_s, display_api_s);
+    g_free (user_api_s);
     g_free (compiled_api_s);
+    g_free (display_api_s);
     goto failure;
   }
 
@@ -1212,18 +1228,21 @@ gst_gl_context_create_thread (GstGLContext * context)
       !context_class->choose_format (context, error)) {
     g_assert (error == NULL || *error != NULL);
     g_free (compiled_api_s);
-    g_free (user_api_string);
+    g_free (user_api_s);
+    g_free (display_api_s);
     goto failure;
   }
 
   GST_INFO ("Attempting to create opengl context. user chosen api(s) (%s), "
-      "compiled api support (%s)", user_api_string, compiled_api_s);
+      "compiled api support (%s) display api (%s)", user_api_s,
+      compiled_api_s, display_api_s);
 
-  if (!context_class->create_context (context, compiled_api & user_api,
+  if (!context_class->create_context (context,
-          other_context, error)) {
+          compiled_api & user_api & display_api, other_context, error)) {
     g_assert (error == NULL || *error != NULL);
     g_free (compiled_api_s);
-    g_free (user_api_string);
+    g_free (user_api_s);
+    g_free (display_api_s);
     goto failure;
   }
   GST_INFO ("created context");
@@ -1233,7 +1252,8 @@ gst_gl_context_create_thread (GstGLContext * context)
         GST_GL_CONTEXT_ERROR_RESOURCE_UNAVAILABLE,
         "Failed to activate the GL Context");
     g_free (compiled_api_s);
-    g_free (user_api_string);
+    g_free (user_api_s);
+    g_free (display_api_s);
     goto failure;
   }
 
@@ -1243,20 +1263,22 @@ gst_gl_context_create_thread (GstGLContext * context)
   api_string = gst_gl_api_to_string (gl_api);
   GST_INFO ("available GL APIs: %s", api_string);
 
-  if (((compiled_api & gl_api) & user_api) == GST_GL_API_NONE) {
+  if (((compiled_api & gl_api & display_api) & user_api) == GST_GL_API_NONE) {
     g_set_error (error, GST_GL_CONTEXT_ERROR, GST_GL_CONTEXT_ERROR_WRONG_API,
         "failed to create context, context "
         "could not provide correct api. user (%s), compiled (%s), context (%s)",
-        user_api_string, compiled_api_s, api_string);
+        user_api_s, compiled_api_s, api_string);
     g_free (api_string);
     g_free (compiled_api_s);
-    g_free (user_api_string);
+    g_free (user_api_s);
+    g_free (display_api_s);
     goto failure;
   }
 
   g_free (api_string);
   g_free (compiled_api_s);
-  g_free (user_api_string);
+  g_free (user_api_s);
+  g_free (display_api_s);
 
   gl->GetError = gst_gl_context_get_proc_address (context, "glGetError");
   gl->GetString = gst_gl_context_get_proc_address (context, "glGetString");

gst-libs/gst/gl/gstgldisplay.c

@@ -83,7 +83,7 @@ static guintptr gst_gl_display_default_get_handle (GstGLDisplay * display);
 
 struct _GstGLDisplayPrivate
 {
-  gint dummy;
+  GstGLAPI gl_api;
 };
 
 static void
@@ -102,6 +102,7 @@ gst_gl_display_init (GstGLDisplay * display)
   display->priv = GST_GL_DISPLAY_GET_PRIVATE (display);
 
   display->type = GST_GL_DISPLAY_TYPE_ANY;
+  display->priv->gl_api = GST_GL_API_ANY;
 
   GST_TRACE ("init %p", display);
 
@@ -192,6 +193,53 @@ gst_gl_display_default_get_handle (GstGLDisplay * display)
   return 0;
 }
 
+/**
+ * gst_gl_display_filter_gl_api:
+ * @display: a #GstGLDisplay
+ *
+ * limit the use of OpenGL to the requested @gl_api.  This is intended to allow
+ * application and elements to request a specific set of OpenGL API's based on
+ * what they support.  See gst_gl_context_get_gl_api() for the retreiving the
+ * API supported by a #GstGLContext.
+ */
+void
+gst_gl_display_filter_gl_api (GstGLDisplay * display, GstGLAPI gl_api)
+{
+  gchar *gl_api_s;
+
+  g_return_if_fail (GST_IS_GL_DISPLAY (display));
+
+  gl_api_s = gst_gl_api_to_string (gl_api);
+  GST_TRACE_OBJECT (display, "filtering with api %s", gl_api_s);
+  g_free (gl_api_s);
+
+  GST_OBJECT_LOCK (display);
+  display->priv->gl_api &= gl_api;
+  GST_OBJECT_UNLOCK (display);
+}
+
+/**
+ * gst_gl_display_get_gl_api:
+ * @display: a #GstGLDisplay
+ *
+ * see gst_gl_display_filter_gl_api() for what the returned value represents
+ *
+ * Returns: the #GstGLAPI configured for @display
+ */
+GstGLAPI
+gst_gl_display_get_gl_api (GstGLDisplay * display)
+{
+  GstGLAPI ret;
+
+  g_return_if_fail (GST_IS_GL_DISPLAY (display));
+
+  GST_OBJECT_LOCK (display);
+  ret = display->priv->gl_api;
+  GST_OBJECT_UNLOCK (display);
+
+  return ret;
+}
+
 /**
  * gst_gl_display_get_handle_type:
  * @display: a #GstGLDisplay

gst-libs/gst/gl/gstgldisplay.h

@@ -83,6 +83,9 @@ GstGLDisplay *gst_gl_display_new (void);
 
 guintptr         gst_gl_display_get_handle             (GstGLDisplay * display);
 GstGLDisplayType gst_gl_display_get_handle_type        (GstGLDisplay * display);
+void             gst_gl_display_filter_gl_api          (GstGLDisplay * display,
+                                                        GstGLAPI api);
+GstGLAPI         gst_gl_display_get_gl_api             (GstGLDisplay * display);
 
 #define GST_GL_DISPLAY_CONTEXT_TYPE "gst.gl.GLDisplay"
 void     gst_context_set_gl_display (GstContext * context, GstGLDisplay * display);

gst-libs/gst/gl/gstglfilter.c

@@ -151,6 +151,7 @@ gst_gl_filter_class_init (GstGLFilterClass * klass)
           "Get OpenGL context",
           GST_GL_TYPE_CONTEXT, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
 
+  klass->supported_gl_api = GST_GL_API_ANY;
   klass->set_caps = NULL;
   klass->filter = NULL;
   klass->display_init_cb = NULL;
@@ -199,18 +200,21 @@ static void
 gst_gl_filter_set_context (GstElement * element, GstContext * context)
 {
   GstGLFilter *filter = GST_GL_FILTER (element);
+  GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (filter);
 
   gst_gl_handle_set_context (element, context, &filter->display,
       &filter->other_context);
+  if (filter->display)
+    gst_gl_display_filter_gl_api (filter->display,
+        filter_class->supported_gl_api);
 }
 
 static gboolean
 gst_gl_filter_query (GstBaseTransform * trans, GstPadDirection direction,
     GstQuery * query)
 {
-  GstGLFilter *filter;
+  GstGLFilter *filter = GST_GL_FILTER (trans);
-
+  GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (filter);
-  filter = GST_GL_FILTER (trans);
 
   switch (GST_QUERY_TYPE (query)) {
     case GST_QUERY_ALLOCATION:
@@ -222,8 +226,12 @@ gst_gl_filter_query (GstBaseTransform * trans, GstPadDirection direction,
     }
     case GST_QUERY_CONTEXT:
     {
-      return gst_gl_handle_context_query ((GstElement *) filter, query,
+      gboolean ret = gst_gl_handle_context_query ((GstElement *) filter, query,
           &filter->display, &filter->other_context);
+      if (filter->display)
+        gst_gl_display_filter_gl_api (filter->display,
+            filter_class->supported_gl_api);
+      return ret;
     }
     default:
       break;
@@ -315,6 +323,9 @@ gst_gl_filter_start (GstBaseTransform * bt)
           &filter->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (filter->display,
+      filter_class->supported_gl_api);
+
   if (filter_class->onStart)
     filter_class->onStart (filter);
 
@@ -855,6 +866,7 @@ gst_gl_filter_propose_allocation (GstBaseTransform * trans,
     GstQuery * decide_query, GstQuery * query)
 {
   GstGLFilter *filter = GST_GL_FILTER (trans);
+  GstGLFilterClass *filter_class = GST_GL_FILTER_GET_CLASS (filter);
   GstBufferPool *pool;
   GstStructure *config;
   GstCaps *caps, *decide_caps;
@@ -896,6 +908,9 @@ gst_gl_filter_propose_allocation (GstBaseTransform * trans,
           &filter->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (filter->display,
+      filter_class->supported_gl_api);
+
   if (!filter->context) {
     filter->context = gst_gl_context_new (filter->display);
     if (!gst_gl_context_create (filter->context, filter->other_context, &error))
@@ -1025,6 +1040,9 @@ gst_gl_filter_decide_allocation (GstBaseTransform * trans, GstQuery * query)
           &filter->other_context))
     return FALSE;
 
+  gst_gl_display_filter_gl_api (filter->display,
+      filter_class->supported_gl_api);
+
   if (gst_query_find_allocation_meta (query,
           GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE, &idx)) {
     GstGLContext *context;
@@ -1294,8 +1312,7 @@ 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_element_data (filter, &filter->display,
+  if (!filter->display)
-          &filter->other_context))
     return GST_FLOW_NOT_NEGOTIATED;
 
   if (!filter->upload) {

gst-libs/gst/gl/gstglfilter.h

@@ -116,6 +116,7 @@ struct _GstGLFilter
 struct _GstGLFilterClass
 {
   GstBaseTransformClass base_transform_class;
+  GstGLAPI supported_gl_api;
 
   gboolean (*set_caps)          (GstGLFilter* filter, GstCaps* incaps, GstCaps* outcaps);
   gboolean (*filter)            (GstGLFilter *filter, GstBuffer *inbuf, GstBuffer *outbuf);