cogl-gst: Add a functions to facilitate layering

These functions are used when attaching frames at a start point other
than layer 0 is required. This could potentially be used to "layer"
videos and textures on top of each other in the CoglPipeline. This
layering could come handy if videos are used as alpha masks or normal
maps, or when arranging layers in a perticular order, so Cogl could
blend them nicely without extra hassle.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit f98b437c9ea79f04ef1ebbb6ff547f58b49b0008)

cogl-gst/Makefile.am

@@ -8,7 +8,6 @@ DISTCLEANFILES =
 EXTRA_DIST =
 
 source_c = \
-	cogl-gst-shader.c \
 	cogl-gst-video-sink.c \
 	$(NULL)
 
@@ -17,13 +16,9 @@ source_h = \
 	cogl-gst-video-sink.h \
 	$(NULL)
 
-source_h_priv = \
-	cogl-gst-shader-private.h \
-	$(NULL)
-
 lib_LTLIBRARIES = libcogl-gst.la
 
-libcogl_gst_la_SOURCES = $(source_c) $(source_h) $(source_h_priv)
+libcogl_gst_la_SOURCES = $(source_c) $(source_h)
 libcogl_gst_la_CFLAGS = $(COGL_DEP_CFLAGS) $(COGL_GST_DEP_CFLAGS) $(COGL_EXTRA_CFLAGS) $(MAINTAINER_CFLAGS)
 libcogl_gst_la_LIBADD = $(top_builddir)/cogl/libcogl.la
 libcogl_gst_la_LIBADD += $(COGL_DEP_LIBS) $(COGL_GST_DEP_LIBS) $(COGL_EXTRA_LDFLAGS)

cogl-gst/cogl-gst-shader-private.h

@@ -1,48 +0,0 @@
-/*
- * Cogl-GStreamer.
- *
- * GStreamer integration library for Cogl.
- *
- * cogl-gst-video-sink-private.h - Miscellaneous video sink functions
- *
- * Authored by Jonathan Matthew  <jonathan@kaolin.wh9.net>,
- *             Chris Lord        <chris@openedhand.com>
- *             Damien Lespiau    <damien.lespiau@intel.com>
- *             Matthew Allum     <mallum@openedhand.com>
- *             Plamena Manolova  <plamena.n.manolova@intel.com>
- *
- * Copyright (C) 2007, 2008 OpenedHand
- * Copyright (C) 2009, 2010, 2013 Intel Corporation
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
- */
-
-#ifndef __COGL_GST_SHADER_PRIVATE_H__
-#define __COGL_GST_SHADER_PRIVATE_H__
-
-extern const char
-_cogl_gst_shader_rgba_to_rgba_decl[];
-
-extern const char
-_cogl_gst_shader_yv12_to_rgba_decl[];
-
-extern const char
-_cogl_gst_shader_ayuv_to_rgba_decl[];
-
-extern const char
-_cogl_gst_shader_default_sample[];
-
-#endif /* __COGL_GST_SHADER_PRIVATE_H__ */

cogl-gst/cogl-gst-shader.c

@@ -1,81 +0,0 @@
-/*
- * Cogl-GStreamer.
- *
- * GStreamer integration library for Cogl.
- *
- * cogl-gst-video-sink-private.h - Miscellaneous video sink functions
- *
- * Authored by Jonathan Matthew  <jonathan@kaolin.wh9.net>,
- *             Chris Lord        <chris@openedhand.com>
- *             Damien Lespiau    <damien.lespiau@intel.com>
- *             Matthew Allum     <mallum@openedhand.com>
- *             Plamena Manolova  <plamena.n.manolova@intel.com>
- *
- * Copyright (C) 2007, 2008 OpenedHand
- * Copyright (C) 2009, 2010, 2013 Intel Corporation
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
- */
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include "cogl-gst-shader-private.h"
-
-const char
-_cogl_gst_shader_rgba_to_rgba_decl[] =
-  "vec4\n"
-  "cogl_gst_sample_video (vec2 UV)\n"
-  "{\n"
-  "  return texture2D (cogl_sampler0, UV);\n"
-  "}\n";
-
-const char
-_cogl_gst_shader_yv12_to_rgba_decl[] =
-  "vec4\n"
-  "cogl_gst_sample_video (vec2 UV)\n"
-  "{\n"
-  "  float y = 1.1640625 * (texture2D (cogl_sampler0, UV).a - 0.0625);\n"
-  "  float u = texture2D (cogl_sampler1, UV).a - 0.5;\n"
-  "  float v = texture2D (cogl_sampler2, UV).a - 0.5;\n"
-  "  vec4 color;\n"
-  "  color.r = y + 1.59765625 * v;\n"
-  "  color.g = y - 0.390625 * u - 0.8125 * v;\n"
-  "  color.b = y + 2.015625 * u;\n"
-  "  color.a = 1.0;\n"
-  "  return color;\n"
-  "}\n";
-
-const char
-_cogl_gst_shader_ayuv_to_rgba_decl[] =
-  "vec4\n"
-  "cogl_gst_sample_video (vec2 UV)\n"
-  "{\n"
-  "  vec4 color = texture2D (cogl_sampler0, UV);\n"
-  "  float y = 1.1640625 * (color.g - 0.0625);\n"
-  "  float u = color.b - 0.5;\n"
-  "  float v = color.a - 0.5;\n"
-  "  color.a = color.r;\n"
-  "  color.r = y + 1.59765625 * v;\n"
-  "  color.g = y - 0.390625 * u - 0.8125 * v;\n"
-  "  color.b = y + 2.015625 * u;\n"
-  "  return color;\n"
-  "}\n";
-
-const char
-_cogl_gst_shader_default_sample[] =
-  "  cogl_layer *= cogl_gst_sample_video (cogl_tex_coord0_in.st);\n";

cogl-gst/cogl-gst-video-sink.c

@@ -43,7 +43,6 @@
 #include <string.h>
 
 #include "cogl-gst-video-sink.h"
-#include "cogl-gst-shader-private.h"
 
 #define COGL_GST_TEXTURE_FLAGS \
        (COGL_TEXTURE_NO_SLICING | COGL_TEXTURE_NO_ATLAS)
@@ -99,6 +98,23 @@ typedef enum
   COGL_GST_RENDERER_NEEDS_GLSL = (1 << 0)
 } CoglGstRendererFlag;
 
+/* We want to cache the snippets instead of recreating a new one every
+ * time we initialise a pipeline so that if we end up recreating the
+ * same pipeline again then Cogl will be able to use the pipeline
+ * cache to avoid linking a redundant identical shader program */
+typedef struct
+{
+  CoglSnippet *vertex_snippet;
+  CoglSnippet *fragment_snippet;
+  CoglSnippet *default_sample_snippet;
+  int start_position;
+} SnippetCacheEntry;
+
+typedef struct
+{
+  GQueue entries;
+} SnippetCache;
+
 typedef struct _CoglGstSource
 {
   GSource source;
@@ -117,8 +133,9 @@ typedef struct _CoglGstRenderer
   CoglGstVideoFormat format;
   int flags;
   GstStaticCaps caps;
-  void (*init) (CoglGstVideoSink *sink);
+  int n_layers;
-  void (*deinit) (CoglGstVideoSink *sink);
+  void (*setup_pipeline) (CoglGstVideoSink *sink,
+                          CoglPipeline *pipeline);
   CoglBool (*upload) (CoglGstVideoSink *sink,
                       GstBuffer *buffer);
 } CoglGstRenderer;
@@ -136,7 +153,9 @@ struct _CoglGstVideoSinkPrivate
   GstCaps *caps;
   CoglGstRenderer *renderer;
   GstFlowReturn flow_return;
+  int custom_start;
   int free_layer;
+  CoglBool default_sample;
   GstVideoInfo info;
 };
 
@@ -168,7 +187,8 @@ cogl_gst_video_sink_attach_frame (CoglGstVideoSink *sink,
 
   for (i = 0; i < G_N_ELEMENTS (priv->frame); i++)
     if (priv->frame[i] != NULL)
-      cogl_pipeline_set_layer_texture (pln, i, priv->frame[i]);
+      cogl_pipeline_set_layer_texture (pln, i + priv->custom_start,
+                                       priv->frame[i]);
 
   return priv->free_layer;
 }
@@ -200,77 +220,139 @@ cogl_gst_video_sink_set_priority (CoglGstVideoSink *sink,
     g_source_set_priority ((GSource *) sink->priv->source, priority);
 }
 
-/* We want to cache the snippets instead of recreating a new one every
- * time we initialise a pipeline so that if we end up recreating the
- * same pipeline again then Cogl will be able to use the pipeline
- * cache to avoid linking a redundant identical shader program */
-typedef struct
-{
-  CoglSnippet *vertex_snippet;
-  CoglSnippet *fragment_snippet;
-} SnippetCache;
-
 static void
-create_template_pipeline (CoglGstVideoSink *sink,
+dirty_default_pipeline (CoglGstVideoSink *sink)
-                          const char *decl,
-                          SnippetCache *snippet_cache,
-                          int n_layers)
 {
   CoglGstVideoSinkPrivate *priv = sink->priv;
-  priv->free_layer = n_layers;
 
   if (priv->pipeline)
-    cogl_object_unref (priv->pipeline);
-  priv->pipeline = cogl_pipeline_new (priv->ctx);
-
-  if (decl)
     {
-      static CoglSnippet *default_sample_snippet = NULL;
+      cogl_object_unref (priv->pipeline);
+      priv->pipeline = NULL;
+    }
+}
+
+void
+cogl_gst_video_sink_set_first_layer (CoglGstVideoSink *sink,
+                                     int first_layer)
+{
+  if (first_layer != sink->priv->custom_start)
+    {
+      sink->priv->custom_start = first_layer;
+      dirty_default_pipeline (sink);
+
+      if (sink->priv->renderer)
+        sink->priv->free_layer = (sink->priv->custom_start +
+                                  sink->priv->renderer->n_layers);
+    }
+}
+
+void
+cogl_gst_video_sink_set_default_sample (CoglGstVideoSink *sink,
+                                        CoglBool default_sample)
+{
+  if (default_sample != sink->priv->default_sample)
+    {
+      sink->priv->default_sample = default_sample;
+      dirty_default_pipeline (sink);
+    }
+}
+
+void
+cogl_gst_video_sink_setup_pipeline (CoglGstVideoSink *sink,
+                                    CoglPipeline *pipeline)
+{
+  sink->priv->renderer->setup_pipeline (sink, pipeline);
+}
+
+static SnippetCacheEntry *
+get_cache_entry (CoglGstVideoSink *sink,
+                 SnippetCache *cache)
+{
+  CoglGstVideoSinkPrivate *priv = sink->priv;
+  GList *l;
+
+  for (l = cache->entries.head; l; l = l->next)
+    {
+      SnippetCacheEntry *entry = l->data;
+
+      if (entry->start_position == priv->custom_start)
+        return entry;
+    }
+
+  return NULL;
+}
+
+static SnippetCacheEntry *
+add_cache_entry (CoglGstVideoSink *sink,
+                 SnippetCache *cache,
+                 const char *decl)
+{
+  CoglGstVideoSinkPrivate *priv = sink->priv;
+  SnippetCacheEntry *entry = g_slice_new (SnippetCacheEntry);
+  char *default_source;
+
+  entry->start_position = priv->custom_start;
+
+  entry->vertex_snippet =
+    cogl_snippet_new (COGL_SNIPPET_HOOK_VERTEX_GLOBALS,
+                      decl,
+                      NULL /* post */);
+  entry->fragment_snippet =
+    cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT_GLOBALS,
+                      decl,
+                      NULL /* post */);
+
+  default_source =
+    g_strdup_printf ("  cogl_layer *= cogl_gst_sample_video%i "
+                     "(cogl_tex_coord%i_in.st);\n",
+                     priv->custom_start,
+                     priv->custom_start);
+  entry->default_sample_snippet =
+    cogl_snippet_new (COGL_SNIPPET_HOOK_LAYER_FRAGMENT,
+                      NULL, /* declarations */
+                      default_source);
+  g_free (default_source);
+
+  g_queue_push_head (&cache->entries, entry);
+
+  return entry;
+}
+
+static void
+setup_pipeline_from_cache_entry (CoglGstVideoSink *sink,
+                                 CoglPipeline *pipeline,
+                                 SnippetCacheEntry *cache_entry,
+                                 int n_layers)
+{
+  CoglGstVideoSinkPrivate *priv = sink->priv;
+
+  if (cache_entry)
+    {
       int i;
 
       /* The global sampling function gets added to both the fragment
        * and vertex stages. The hope is that the GLSL compiler will
        * easily remove the dead code if it's not actually used */
-      if (snippet_cache->vertex_snippet == NULL)
+      cogl_pipeline_add_snippet (pipeline, cache_entry->vertex_snippet);
-        snippet_cache->vertex_snippet =
+      cogl_pipeline_add_snippet (pipeline, cache_entry->fragment_snippet);
-          cogl_snippet_new (COGL_SNIPPET_HOOK_VERTEX_GLOBALS,
-                            decl,
-                            NULL /* post */);
-      cogl_pipeline_add_snippet (priv->pipeline,
-                                 snippet_cache->vertex_snippet);
-
-      if (snippet_cache->fragment_snippet == NULL)
-        snippet_cache->fragment_snippet =
-          cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT_GLOBALS,
-                            decl,
-                            NULL /* post */);
-      cogl_pipeline_add_snippet (priv->pipeline,
-                                 snippet_cache->fragment_snippet);
 
       /* Set all of the layers to just directly copy from the previous
        * layer so that it won't redundantly generate code to sample
        * the intermediate textures */
       for (i = 0; i < n_layers; i++)
-        cogl_pipeline_set_layer_combine (priv->pipeline,
+        cogl_pipeline_set_layer_combine (pipeline,
-                                         i,
+                                         priv->custom_start + i,
                                          "RGBA=REPLACE(PREVIOUS)",
                                          NULL);
 
-      if (default_sample_snippet == NULL)
+      if (priv->default_sample)
-        {
+        cogl_pipeline_add_layer_snippet (pipeline,
-          default_sample_snippet =
+                                         priv->custom_start + n_layers - 1,
-            cogl_snippet_new (COGL_SNIPPET_HOOK_LAYER_FRAGMENT,
+                                         cache_entry->default_sample_snippet);
-                              NULL, /* declarations */
-                              _cogl_gst_shader_default_sample);
-        }
-      cogl_pipeline_add_layer_snippet (priv->pipeline,
-                                       n_layers - 1,
-                                       default_sample_snippet);
     }
 
   priv->frame_dirty = TRUE;
-
-  g_signal_emit (sink, video_sink_signals[PIPELINE_READY_SIGNAL], 0, NULL);
 }
 
 CoglPipeline *
@@ -278,23 +360,24 @@ cogl_gst_video_sink_get_pipeline (CoglGstVideoSink *vt)
 {
   CoglGstVideoSinkPrivate *priv = vt->priv;
 
-  if (priv->frame_dirty)
+  if (priv->pipeline == NULL)
+    {
+      priv->pipeline = cogl_pipeline_new (priv->ctx);
+      cogl_gst_video_sink_setup_pipeline (vt, priv->pipeline);
+      cogl_gst_video_sink_attach_frame (vt, priv->pipeline);
+      priv->frame_dirty = FALSE;
+    }
+  else if (priv->frame_dirty)
     {
       CoglPipeline *pipeline = cogl_pipeline_copy (priv->pipeline);
       cogl_object_unref (priv->pipeline);
       priv->pipeline = pipeline;
 
       cogl_gst_video_sink_attach_frame (vt, pipeline);
-
       priv->frame_dirty = FALSE;
     }
 
-  return vt->priv->pipeline;
+  return priv->pipeline;
-}
-
-static void
-cogl_gst_dummy_deinit (CoglGstVideoSink *sink)
-{
 }
 
 static void
@@ -317,21 +400,35 @@ clear_frame_textures (CoglGstVideoSink *sink)
 }
 
 static void
-cogl_gst_rgb_init (CoglGstVideoSink *sink)
+cogl_gst_rgb_setup_pipeline (CoglGstVideoSink *sink,
+                             CoglPipeline *pipeline)
 {
   CoglGstVideoSinkPrivate *priv = sink->priv;
 
   if (cogl_has_feature (priv->ctx, COGL_FEATURE_ID_GLSL))
     {
       static SnippetCache snippet_cache;
+      SnippetCacheEntry *entry = get_cache_entry (sink, &snippet_cache);
 
-      create_template_pipeline (sink,
+      if (entry == NULL)
-                                _cogl_gst_shader_rgba_to_rgba_decl,
+        {
-                                &snippet_cache,
+          char *source;
-                                1);
+
+          source =
+            g_strdup_printf ("vec4\n"
+                             "cogl_gst_sample_video%i (vec2 UV)\n"
+                             "{\n"
+                             "  return texture2D (cogl_sampler%i, UV);\n"
+                             "}\n",
+                             priv->custom_start,
+                             priv->custom_start);
+
+          setup_pipeline_from_cache_entry (sink, pipeline, entry, 1);
+          g_free (source);
+        }
     }
   else
-    create_template_pipeline (sink, NULL, NULL, 1);
+    setup_pipeline_from_cache_entry (sink, pipeline, NULL, 1);
 }
 
 static CoglBool
@@ -376,8 +473,8 @@ static CoglGstRenderer rgb24_renderer =
   COGL_GST_RGB24,
   0,
   GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("{ RGB, BGR }")),
-  cogl_gst_rgb_init,
+  1, /* n_layers */
-  cogl_gst_dummy_deinit,
+  cogl_gst_rgb_setup_pipeline,
   cogl_gst_rgb24_upload,
 };
 
@@ -423,8 +520,8 @@ static CoglGstRenderer rgb32_renderer =
   COGL_GST_RGB32,
   0,
   GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("{ RGBA, BGRA }")),
-  cogl_gst_rgb_init,
+  1, /* n_layers */
-  cogl_gst_dummy_deinit,
+  cogl_gst_rgb_setup_pipeline,
   cogl_gst_rgb32_upload,
 };
 
@@ -471,14 +568,44 @@ map_fail:
 }
 
 static void
-cogl_gst_yv12_glsl_init (CoglGstVideoSink *sink)
+cogl_gst_yv12_glsl_setup_pipeline (CoglGstVideoSink *sink,
+                                   CoglPipeline *pipeline)
 {
+  CoglGstVideoSinkPrivate *priv = sink->priv;
   static SnippetCache snippet_cache;
+  SnippetCacheEntry *entry;
 
-  create_template_pipeline (sink,
+  entry = get_cache_entry (sink, &snippet_cache);
-                            _cogl_gst_shader_yv12_to_rgba_decl,
+
-                            &snippet_cache,
+  if (entry == NULL)
-                            3);
+    {
+      char *source;
+
+      source =
+        g_strdup_printf ("vec4\n"
+                         "cogl_gst_sample_video%i (vec2 UV)\n"
+                         "{\n"
+                         "  float y = 1.1640625 * "
+                         "(texture2D (cogl_sampler%i, UV).a - 0.0625);\n"
+                         "  float u = texture2D (cogl_sampler%i, UV).a - 0.5;\n"
+                         "  float v = texture2D (cogl_sampler%i, UV).a - 0.5;\n"
+                         "  vec4 color;\n"
+                         "  color.r = y + 1.59765625 * v;\n"
+                         "  color.g = y - 0.390625 * u - 0.8125 * v;\n"
+                         "  color.b = y + 2.015625 * u;\n"
+                         "  color.a = 1.0;\n"
+                         "  return color;\n"
+                         "}\n",
+                         priv->custom_start,
+                         priv->custom_start,
+                         priv->custom_start + 1,
+                         priv->custom_start + 2);
+
+      entry = add_cache_entry (sink, &snippet_cache, source);
+      g_free (source);
+    }
+
+  setup_pipeline_from_cache_entry (sink, pipeline, entry, 3);
 }
 
 static CoglGstRenderer yv12_glsl_renderer =
@@ -487,42 +614,57 @@ static CoglGstRenderer yv12_glsl_renderer =
   COGL_GST_YV12,
   COGL_GST_RENDERER_NEEDS_GLSL,
   GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("YV12")),
-  cogl_gst_yv12_glsl_init,
+  3, /* n_layers */
-  cogl_gst_dummy_deinit,
+  cogl_gst_yv12_glsl_setup_pipeline,
   cogl_gst_yv12_upload,
 };
 
-static void
-cogl_gst_i420_glsl_init (CoglGstVideoSink *sink)
-{
-  static SnippetCache snippet_cache;
-
-  create_template_pipeline (sink,
-                            _cogl_gst_shader_yv12_to_rgba_decl,
-                            &snippet_cache,
-                            3);
-}
-
 static CoglGstRenderer i420_glsl_renderer =
 {
   "I420 glsl",
   COGL_GST_I420,
   COGL_GST_RENDERER_NEEDS_GLSL,
   GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("I420")),
-  cogl_gst_i420_glsl_init,
+  3, /* n_layers */
-  cogl_gst_dummy_deinit,
+  cogl_gst_yv12_glsl_setup_pipeline,
   cogl_gst_yv12_upload,
 };
 
 static void
-cogl_gst_ayuv_glsl_init (CoglGstVideoSink *sink)
+cogl_gst_ayuv_glsl_setup_pipeline (CoglGstVideoSink *sink,
+                                   CoglPipeline *pipeline)
 {
+  CoglGstVideoSinkPrivate *priv = sink->priv;
   static SnippetCache snippet_cache;
+  SnippetCacheEntry *entry;
 
-  create_template_pipeline (sink,
+  entry = get_cache_entry (sink, &snippet_cache);
-                            _cogl_gst_shader_ayuv_to_rgba_decl,
+
-                            &snippet_cache,
+  if (entry == NULL)
-                            1);
+    {
+      char *source;
+
+      source
+        = g_strdup_printf ("vec4\n"
+                           "cogl_gst_sample_video%i (vec2 UV)\n"
+                           "{\n"
+                           "  vec4 color = texture2D (cogl_sampler%i, UV);\n"
+                           "  float y = 1.1640625 * (color.g - 0.0625);\n"
+                           "  float u = color.b - 0.5;\n"
+                           "  float v = color.a - 0.5;\n"
+                           "  color.a = color.r;\n"
+                           "  color.r = y + 1.59765625 * v;\n"
+                           "  color.g = y - 0.390625 * u - 0.8125 * v;\n"
+                           "  color.b = y + 2.015625 * u;\n"
+                           "  return color;\n"
+                           "}\n", priv->custom_start,
+                           priv->custom_start);
+
+      entry = add_cache_entry (sink, &snippet_cache, source);
+      g_free (source);
+    }
+
+  setup_pipeline_from_cache_entry (sink, pipeline, entry, 3);
 }
 
 static CoglBool
@@ -562,8 +704,8 @@ static CoglGstRenderer ayuv_glsl_renderer =
   COGL_GST_AYUV,
   COGL_GST_RENDERER_NEEDS_GLSL,
   GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("AYUV")),
-  cogl_gst_ayuv_glsl_init,
+  3, /* n_layers */
-  cogl_gst_dummy_deinit,
+  cogl_gst_ayuv_glsl_setup_pipeline,
   cogl_gst_ayuv_upload,
 };
 
@@ -811,14 +953,21 @@ cogl_gst_source_dispatch (GSource *source,
         gst_pad_get_current_caps (GST_BASE_SINK_PAD ((GST_BASE_SINK
                 (gst_source->sink))));
 
-      if (priv->renderer)
-        priv->renderer->deinit (gst_source->sink);
-
       if (!cogl_gst_video_sink_parse_caps (caps, gst_source->sink, TRUE))
         goto negotiation_fail;
 
-      priv->renderer->init (gst_source->sink);
       gst_source->has_new_caps = FALSE;
+      priv->free_layer = priv->custom_start + priv->renderer->n_layers;
+
+      dirty_default_pipeline (gst_source->sink);
+
+      /* We are now in a state where we could generate the pipeline if
+       * the application requests it so we can emit the signal.
+       * However we'll actually generate the pipeline lazily only if
+       * the application actually asks for it. */
+      g_signal_emit (gst_source->sink,
+                     video_sink_signals[PIPELINE_READY_SIGNAL],
+                     0 /* detail */);
     }
 
   buffer = gst_source->buffer;
@@ -939,12 +1088,6 @@ cogl_gst_video_sink_dispose (GObject *object)
 
   clear_frame_textures (self);
 
-  if (priv->renderer)
-    {
-      priv->renderer->deinit (self);
-      priv->renderer = NULL;
-    }
-
   if (priv->pipeline)
     {
       cogl_object_unref (priv->pipeline);
@@ -1110,6 +1253,8 @@ cogl_gst_video_sink_new (CoglContext *ctx)
 {
   CoglGstVideoSink *sink = g_object_new (COGL_GST_TYPE_VIDEO_SINK, NULL);
   cogl_gst_video_sink_set_context (sink, ctx);
+  sink->priv->custom_start = 0;
+  sink->priv->default_sample = TRUE;
 
   return sink;
 }

cogl-gst/cogl-gst-video-sink.h

@@ -116,6 +116,17 @@ int
 cogl_gst_video_sink_attach_frame (CoglGstVideoSink *sink,
                                   CoglPipeline *pln);
 
+void
+cogl_gst_video_sink_set_first_layer (CoglGstVideoSink *sink,
+                                     int first_layer);
+
+void
+cogl_gst_video_sink_set_default_sample (CoglGstVideoSink *sink,
+                                        CoglBool default_sample);
+
+void
+cogl_gst_video_sink_setup_pipeline (CoglGstVideoSink *sink,
+                                    CoglPipeline *pipeline);
 G_END_DECLS
 
 #endif