ext/gl/gstgleffects.c - mtk-gst-plugins-bad-debian - Git at Google

 /*
  * GStreamer
  * Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library 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
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the
  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 /**
  * SECTION:element-gleffects.
  *
  * GL Shading Language effects.
  *
  * <refsect2>
  * <title>Examples</title>
  * |[
  * gst-launch videotestsrc ! glupload ! gleffects effect=5 ! glimagesink
  * ]|
  * FBO (Frame Buffer Object) and GLSL (OpenGL Shading Language) are required.
  * </refsect2>
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <gst/gl/gstglconfig.h>
 #include "gstgleffects.h"

 #define GST_CAT_DEFAULT gst_gl_effects_debug
 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

 enum
 {
   PROP_0 = 0x0,
   PROP_EFFECT = 0x1 << 1,
   PROP_HSWAP = 0x1 << 2,
   PROP_INVERT = 0x1 << 3
 };

 #define DEBUG_INIT \
   GST_DEBUG_CATEGORY_INIT (gst_gl_effects_debug, "gleffects", 0, "gleffects element");

 #define gst_gl_effects_parent_class parent_class
 G_DEFINE_TYPE_WITH_CODE (GstGLEffects, gst_gl_effects, GST_TYPE_GL_FILTER,
     DEBUG_INIT);

 static void gst_gl_effects_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
 static void gst_gl_effects_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);

 static gboolean gst_gl_effects_init_resources (GstBaseTransform * trans);
 static gboolean gst_gl_effects_reset_resources (GstBaseTransform * trans);

 static gboolean gst_gl_effects_on_init_gl_context (GstGLFilter * filter);

 static void gst_gl_effects_ghash_func_clean (gpointer key, gpointer value,
     gpointer data);

 static gboolean gst_gl_effects_filter_texture (GstGLFilter * filter,
     guint in_tex, guint out_tex);
 static gboolean gst_gl_effects_filters_is_property_supported (const
     GstGLEffectsFilterDescriptor *, gint property);

 /* dont' forget to edit the following when a new effect is added */
 typedef enum
 {
   GST_GL_EFFECT_IDENTITY,
   GST_GL_EFFECT_MIRROR,
   GST_GL_EFFECT_SQUEEZE,
   GST_GL_EFFECT_STRETCH,
   GST_GL_EFFECT_TUNNEL,
   GST_GL_EFFECT_FISHEYE,
   GST_GL_EFFECT_TWIRL,
   GST_GL_EFFECT_BULGE,
   GST_GL_EFFECT_SQUARE,
   GST_GL_EFFECT_HEAT,
   GST_GL_EFFECT_SEPIA,
   GST_GL_EFFECT_XPRO,
   GST_GL_EFFECT_LUMA_XPRO,
   GST_GL_EFFECT_XRAY,
   GST_GL_EFFECT_SIN,
   GST_GL_EFFECT_GLOW,
   GST_GL_EFFECT_SOBEL,
   GST_GL_EFFECT_BLUR,
   GST_GL_EFFECT_LAPLACIAN,
   GST_GL_N_EFFECTS
 } GstGLEffectsEffect;

 static const GEnumValue *
 gst_gl_effects_get_effects (void)
 {
   static const GEnumValue effect_types[] = {
     {GST_GL_EFFECT_IDENTITY, "Do nothing Effect", "identity"},
     {GST_GL_EFFECT_MIRROR, "Mirror Effect", "mirror"},
     {GST_GL_EFFECT_SQUEEZE, "Squeeze Effect", "squeeze"},
     {GST_GL_EFFECT_STRETCH, "Stretch Effect", "stretch"},
     {GST_GL_EFFECT_TUNNEL, "Light Tunnel Effect", "tunnel"},
     {GST_GL_EFFECT_FISHEYE, "FishEye Effect", "fisheye"},
     {GST_GL_EFFECT_TWIRL, "Twirl Effect", "twirl"},
     {GST_GL_EFFECT_BULGE, "Bulge Effect", "bulge"},
     {GST_GL_EFFECT_SQUARE, "Square Effect", "square"},
     {GST_GL_EFFECT_HEAT, "Heat Signature Effect", "heat"},
     {GST_GL_EFFECT_SEPIA, "Sepia Toning Effect", "sepia"},
     {GST_GL_EFFECT_XPRO, "Cross Processing Effect", "xpro"},
     {GST_GL_EFFECT_LUMA_XPRO, "Luma Cross Processing Effect", "lumaxpro"},
     {GST_GL_EFFECT_XRAY, "Glowing negative effect", "xray"},
     {GST_GL_EFFECT_SIN, "All Grey but Red Effect", "sin"},
     {GST_GL_EFFECT_GLOW, "Glow Lighting Effect", "glow"},
     {GST_GL_EFFECT_SOBEL, "Sobel edge detection Effect", "sobel"},
     {GST_GL_EFFECT_BLUR, "Blur with 9x9 separable convolution Effect", "blur"},
     {GST_GL_EFFECT_LAPLACIAN, "Laplacian Convolution Demo Effect", "laplacian"},
     {0, NULL, NULL}
   };
   return effect_types;
 }

 #define GST_TYPE_GL_EFFECTS_EFFECT (gst_gl_effects_effect_get_type ())
 static GType
 gst_gl_effects_effect_get_type (void)
 {
   static GType gl_effects_effect_type = 0;
   if (!gl_effects_effect_type) {
     gl_effects_effect_type =
         g_enum_register_static ("GstGLEffectsEffect",
         gst_gl_effects_get_effects ());
   }
   return gl_effects_effect_type;
 }

 static void
 gst_gl_effects_set_effect (GstGLEffects * effects, gint effect_type)
 {
   GstGLBaseFilterClass *filter_class = GST_GL_BASE_FILTER_GET_CLASS (effects);

   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;
     case GST_GL_EFFECT_STRETCH:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_stretch;
       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_TUNNEL:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_tunnel;
       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_FISHEYE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_fisheye;
       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_TWIRL:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_twirl;
       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_BULGE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_bulge;
       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_SQUARE:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_square;
       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_HEAT:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_heat;
       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_SEPIA:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sepia;
       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_XPRO:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_xpro;
       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_LUMA_XPRO:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_luma_xpro;
       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_SIN:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
       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_XRAY:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
       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_GLOW:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_glow;
       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_SOBEL:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sobel;
       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_BLUR:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_blur;
       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_LAPLACIAN:
       effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_laplacian;
       filter_class->supported_gl_api =
           GST_GL_API_GLES2 | GST_GL_API_OPENGL | GST_GL_API_OPENGL3;
       effects->current_effect = effect_type;
       break;
     default:
       g_assert_not_reached ();
   }

   effects->current_effect = effect_type;
 }

 /* init resources that need a gl context */
 static void
 gst_gl_effects_init_gl_resources (GstGLFilter * filter)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (filter);
   GstGLContext *context = GST_GL_BASE_FILTER (filter)->context;
   GstGLFuncs *gl = context->gl_vtable;
   guint internal_format;
   gint i = 0;

   for (i = 0; i < NEEDED_TEXTURES; i++) {

     if (effects->midtexture[i]) {
       gl->DeleteTextures (1, &effects->midtexture[i]);
       effects->midtexture[i] = 0;
     }

     gl->GenTextures (1, &effects->midtexture[i]);
     gl->BindTexture (GL_TEXTURE_2D, effects->midtexture[i]);
     internal_format =
         gst_gl_sized_gl_format_from_gl_format_type (context, GL_RGBA,
         GL_UNSIGNED_BYTE);
     gl->TexImage2D (GL_TEXTURE_2D, 0, internal_format,
         GST_VIDEO_INFO_WIDTH (&filter->out_info),
         GST_VIDEO_INFO_HEIGHT (&filter->out_info), 0, GL_RGBA, GL_UNSIGNED_BYTE,
         NULL);
     gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
   }
 }

 /* free resources that need a gl context */
 static void
 gst_gl_effects_reset_gl_resources (GstGLFilter * filter)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (filter);
   GstGLFuncs *gl = GST_GL_BASE_FILTER (filter)->context->gl_vtable;
   gint i = 0;

   for (i = 0; i < NEEDED_TEXTURES; i++) {
     gl->DeleteTextures (1, &effects->midtexture[i]);
     effects->midtexture[i] = 0;
   }
   for (i = 0; i < GST_GL_EFFECTS_N_CURVES; i++) {
     gl->DeleteTextures (1, &effects->curve[i]);
     effects->curve[i] = 0;
   }
 }

 static void
 gst_gl_effects_class_init (GstGLEffectsClass * klass)
 {
   GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

   GST_BASE_TRANSFORM_CLASS (klass)->start = gst_gl_effects_init_resources;
   GST_BASE_TRANSFORM_CLASS (klass)->stop = gst_gl_effects_reset_resources;

   GST_GL_FILTER_CLASS (klass)->filter_texture = gst_gl_effects_filter_texture;
   GST_GL_FILTER_CLASS (klass)->display_init_cb =
       gst_gl_effects_init_gl_resources;
   GST_GL_FILTER_CLASS (klass)->display_reset_cb =
       gst_gl_effects_reset_gl_resources;
   GST_GL_FILTER_CLASS (klass)->init_fbo = gst_gl_effects_on_init_gl_context;

   klass->filter_descriptor = NULL;

   gst_element_class_set_metadata (element_class,
       "Gstreamer OpenGL Effects", "Filter/Effect/Video",
       "GL Shading Language effects",
       "Filippo Argiolas <filippo.argiolas@gmail.com>");

   GST_GL_BASE_FILTER_CLASS (klass)->supported_gl_api =
       GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3;
 }

 static void
 gst_gl_effects_filter_class_init (GstGLEffectsClass * klass,
     const GstGLEffectsFilterDescriptor * filter_descriptor)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

   klass->filter_descriptor = filter_descriptor;

   gobject_class->set_property = gst_gl_effects_set_property;
   gobject_class->get_property = gst_gl_effects_get_property;

   /* if filterDescriptor is null it's a generic gleffects */
   if (!filter_descriptor) {
     g_object_class_install_property (gobject_class,
         PROP_EFFECT,
         g_param_spec_enum ("effect",
             "Effect",
             "Select which effect apply to GL video texture",
             GST_TYPE_GL_EFFECTS_EFFECT,
             GST_GL_EFFECT_IDENTITY,
             G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   }

   g_object_class_install_property (gobject_class,
       PROP_HSWAP,
       g_param_spec_boolean ("hswap",
           "Horizontal Swap",
           "Switch video texture left to right, useful with webcams",
           FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

   /* FIXME: make it work on every effect */
   if (gst_gl_effects_filters_is_property_supported (filter_descriptor,
           PROP_INVERT)) {
     g_object_class_install_property (gobject_class, PROP_INVERT,
         g_param_spec_boolean ("invert", "Invert the colors for sobel effect",
             "Invert colors to get dark edges on bright background when using sobel effect",
             FALSE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
   }
 }

 static void
 set_horizontal_swap (GstGLContext * context, gpointer data)
 {
 #if GST_GL_HAVE_OPENGL
   GstGLFuncs *gl = context->gl_vtable;

   if (gst_gl_context_get_gl_api (context) & GST_GL_API_OPENGL) {
     const gfloat mirrormatrix[16] = {
       -1.0, 0.0, 0.0, 0.0,
       0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0
     };

     gl->MatrixMode (GL_MODELVIEW);
     gl->LoadMatrixf (mirrormatrix);
   }
 #endif
 }

 static void
 gst_gl_effects_init (GstGLEffects * effects)
 {
   effects->horizontal_swap = FALSE;
   effects->invert = FALSE;
   effects->effect = gst_gl_effects_identity;
 }

 static void
 gst_gl_effects_filter_init (GstGLEffects * effects)
 {
   gst_gl_effects_set_effect (effects,
       GST_GL_EFFECTS_GET_CLASS (effects)->filter_descriptor->effect);
 }

 static void
 gst_gl_effects_ghash_func_clean (gpointer key, gpointer value, gpointer data)
 {
   GstGLShader *shader = (GstGLShader *) value;
   GstGLFilter *filter = (GstGLFilter *) data;

   //blocking call, wait the opengl thread has destroyed the shader
   gst_gl_context_del_shader (GST_GL_BASE_FILTER (filter)->context, shader);

   value = NULL;
 }

 static gboolean
 gst_gl_effects_reset_resources (GstBaseTransform * trans)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (trans);

   /* release shaders in the gl thread */
   g_hash_table_foreach (effects->shaderstable, gst_gl_effects_ghash_func_clean,
       effects);

   /* clean the htable without calling values destructors
    * because shaders have been released in the glthread
    * through the foreach func */
   g_hash_table_unref (effects->shaderstable);
   effects->shaderstable = NULL;

   return GST_BASE_TRANSFORM_CLASS (parent_class)->stop (trans);
 }

 static void
 gst_gl_effects_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (object);

   switch (prop_id) {
     case PROP_EFFECT:
       gst_gl_effects_set_effect (effects, g_value_get_enum (value));
       break;
     case PROP_HSWAP:
       effects->horizontal_swap = g_value_get_boolean (value);
       break;
     case PROP_INVERT:
       effects->invert = g_value_get_boolean (value);
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
   }
 }

 static void
 gst_gl_effects_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (object);

   switch (prop_id) {
     case PROP_EFFECT:
       g_value_set_enum (value, effects->current_effect);
       break;
     case PROP_HSWAP:
       g_value_set_boolean (value, effects->horizontal_swap);
       break;
     case PROP_INVERT:
       g_value_set_boolean (value, effects->invert);
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
   }
 }

 static gboolean
 gst_gl_effects_init_resources (GstBaseTransform * trans)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (trans);
   gint i;

   effects->shaderstable = g_hash_table_new (g_str_hash, g_str_equal);

   for (i = 0; i < NEEDED_TEXTURES; i++) {
     effects->midtexture[i] = 0;
   }
   for (i = 0; i < GST_GL_EFFECTS_N_CURVES; i++) {
     effects->curve[i] = 0;
   }

   return GST_BASE_TRANSFORM_CLASS (parent_class)->start (trans);
 }

 static gboolean
 gst_gl_effects_on_init_gl_context (GstGLFilter * filter)
 {
   return TRUE;
 }

 static gboolean
 gst_gl_effects_filter_texture (GstGLFilter * filter, guint in_tex,
     guint out_tex)
 {
   GstGLEffects *effects = GST_GL_EFFECTS (filter);

   effects->intexture = in_tex;
   effects->outtexture = out_tex;

   if (effects->horizontal_swap == TRUE)
     gst_gl_context_thread_add (GST_GL_BASE_FILTER (filter)->context,
         set_horizontal_swap, effects);

   effects->effect (effects);

   return TRUE;
 }

 GstGLShader *
 gst_gl_effects_get_fragment_shader (GstGLEffects * effects,
     const gchar * shader_name, const gchar * shader_source_gles2,
     const gchar * shader_source_opengl)
 {
   GstGLShader *shader = NULL;
   GstGLFilter *filter = GST_GL_FILTER (effects);
   GstGLContext *context = GST_GL_BASE_FILTER (filter)->context;

   shader = g_hash_table_lookup (effects->shaderstable, shader_name);

   if (!shader) {
     if (!shader && (USING_GLES2 (context) || USING_OPENGL3 (context))) {
       shader = gst_gl_shader_new (context);
       if (!gst_gl_shader_compile_with_default_v_and_check (shader,
               shader_source_gles2, &filter->draw_attr_position_loc,
               &filter->draw_attr_texture_loc)) {
         /* gst gl context error is already set */
         GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND,
             ("Failed to initialize %s shader, %s",
                 shader_name, gst_gl_context_get_error ()), (NULL));
         gst_object_unref (shader);
         shader = NULL;
       }
     }
 #if GST_GL_HAVE_OPENGL
     if (!shader && USING_OPENGL (context)) {
       shader = gst_gl_shader_new (context);
       if (!gst_gl_shader_compile_and_check (shader,
               shader_source_opengl, GST_GL_SHADER_FRAGMENT_SOURCE)) {
         gst_gl_context_set_error (context, "Failed to initialize %s shader",
             shader_name);
         GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND, ("%s",
                 gst_gl_context_get_error ()), (NULL));
         gst_object_unref (shader);
         shader = NULL;
       }
     }
 #endif

     if (!shader)
       return NULL;

     g_hash_table_insert (effects->shaderstable, (gchar *) shader_name, shader);
   }

   return shader;
 }

 static const GstGLEffectsFilterDescriptor *
 gst_gl_effects_filters_supported_properties (void)
 {
   /* Horizontal swap property is supported by all filters */
   static const GstGLEffectsFilterDescriptor effects[] = {
     {GST_GL_EFFECT_SOBEL, PROP_INVERT, NULL},
     {GST_GL_EFFECT_LAPLACIAN, PROP_INVERT, NULL},
     {0, 0, NULL}
   };
   return effects;
 }

 static inline gboolean
 gst_gl_effects_filters_is_property_supported (const GstGLEffectsFilterDescriptor
     * descriptor, gint property)
 {
   /* generic filter (NULL descriptor) supports all properties */
   return !descriptor || (descriptor->supported_properties & property);
 }

 static const GstGLEffectsFilterDescriptor *
 gst_gl_effects_filters_descriptors (void)
 {
   static GstGLEffectsFilterDescriptor *descriptors = NULL;
   if (!descriptors) {
     const GEnumValue *e;
     const GEnumValue *effect = gst_gl_effects_get_effects ();
     const GstGLEffectsFilterDescriptor *defined;
     guint n_filters = 0, i;

     for (e = effect; NULL != e->value_nick; ++e, ++n_filters) {
     }

     descriptors = g_new0 (GstGLEffectsFilterDescriptor, n_filters + 1);
     for (i = 0; i < n_filters; ++i, ++effect) {
       descriptors[i].effect = effect->value;
       descriptors[i].filter_name = effect->value_nick;
     }

     for (defined = gst_gl_effects_filters_supported_properties ();
         0 != defined->supported_properties; ++defined) {

       for (i = 0; i < n_filters; ++i) {
         if (descriptors[i].effect == defined->effect) {
           descriptors[i].supported_properties = defined->supported_properties;
           break;
         }
       }
       if (i >= n_filters) {
         GST_WARNING ("Could not match gstgleffects-%s descriptor",
             defined->filter_name);
       }
     }
   }
   return descriptors;
 }

 gboolean
 gst_gl_effects_register_filters (GstPlugin * plugin, GstRank rank)
 {
   static volatile gsize registered = 0;

   if (g_once_init_enter (&registered)) {
     GTypeInfo info = {
       sizeof (GstGLEffectsClass),
       NULL,
       NULL,
       (GClassInitFunc) gst_gl_effects_filter_class_init,
       NULL,
       NULL,
       sizeof (GstGLEffects),
       0,
       NULL
     };
     GType generic_type =
         g_type_register_static (GST_TYPE_GL_EFFECTS, "GstGLEffectsGeneric",
         &info, 0);

     if (gst_element_register (plugin, "gleffects", rank, generic_type)) {
       const GstGLEffectsFilterDescriptor *filters;
       for (filters = gst_gl_effects_filters_descriptors ();
           NULL != filters->filter_name; ++filters) {
         gchar *name = g_strdup_printf ("gleffects_%s", filters->filter_name);
         GTypeInfo info = {
           sizeof (GstGLEffectsClass),
           NULL,
           NULL,
           (GClassInitFunc) gst_gl_effects_filter_class_init,
           NULL,
           filters,
           sizeof (GstGLEffects),
           0,
           (GInstanceInitFunc) gst_gl_effects_filter_init
         };
         GType type =
             g_type_register_static (GST_TYPE_GL_EFFECTS, name, &info, 0);
         if (!gst_element_register (plugin, name, rank, type)) {
           GST_WARNING ("Could not register %s", name);
         }
         g_free (name);
       }
     }
     g_once_init_leave (&registered, generic_type);
   }
   return registered;
 }
	/*
	* GStreamer
	* Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library 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
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public
	* License along with this library; if not, write to the
	* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	/**
	* SECTION:element-gleffects.
	*
	* GL Shading Language effects.
	*
	* <refsect2>
	* <title>Examples</title>
	* \|[
	* gst-launch videotestsrc ! glupload ! gleffects effect=5 ! glimagesink
	* ]\|
	* FBO (Frame Buffer Object) and GLSL (OpenGL Shading Language) are required.
	* </refsect2>
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <gst/gl/gstglconfig.h>
	#include "gstgleffects.h"

	#define GST_CAT_DEFAULT gst_gl_effects_debug
	GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

	enum
	{
	PROP_0 = 0x0,
	PROP_EFFECT = 0x1 << 1,
	PROP_HSWAP = 0x1 << 2,
	PROP_INVERT = 0x1 << 3
	};

	#define DEBUG_INIT \
	GST_DEBUG_CATEGORY_INIT (gst_gl_effects_debug, "gleffects", 0, "gleffects element");

	#define gst_gl_effects_parent_class parent_class
	G_DEFINE_TYPE_WITH_CODE (GstGLEffects, gst_gl_effects, GST_TYPE_GL_FILTER,
	DEBUG_INIT);

	static void gst_gl_effects_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec);
	static void gst_gl_effects_get_property (GObject * object, guint prop_id,
	GValue * value, GParamSpec * pspec);

	static gboolean gst_gl_effects_init_resources (GstBaseTransform * trans);
	static gboolean gst_gl_effects_reset_resources (GstBaseTransform * trans);

	static gboolean gst_gl_effects_on_init_gl_context (GstGLFilter * filter);

	static void gst_gl_effects_ghash_func_clean (gpointer key, gpointer value,
	gpointer data);

	static gboolean gst_gl_effects_filter_texture (GstGLFilter * filter,
	guint in_tex, guint out_tex);
	static gboolean gst_gl_effects_filters_is_property_supported (const
	GstGLEffectsFilterDescriptor *, gint property);

	/* dont' forget to edit the following when a new effect is added */
	typedef enum
	{
	GST_GL_EFFECT_IDENTITY,
	GST_GL_EFFECT_MIRROR,
	GST_GL_EFFECT_SQUEEZE,
	GST_GL_EFFECT_STRETCH,
	GST_GL_EFFECT_TUNNEL,
	GST_GL_EFFECT_FISHEYE,
	GST_GL_EFFECT_TWIRL,
	GST_GL_EFFECT_BULGE,
	GST_GL_EFFECT_SQUARE,
	GST_GL_EFFECT_HEAT,
	GST_GL_EFFECT_SEPIA,
	GST_GL_EFFECT_XPRO,
	GST_GL_EFFECT_LUMA_XPRO,
	GST_GL_EFFECT_XRAY,
	GST_GL_EFFECT_SIN,
	GST_GL_EFFECT_GLOW,
	GST_GL_EFFECT_SOBEL,
	GST_GL_EFFECT_BLUR,
	GST_GL_EFFECT_LAPLACIAN,
	GST_GL_N_EFFECTS
	} GstGLEffectsEffect;

	static const GEnumValue *
	gst_gl_effects_get_effects (void)
	{
	static const GEnumValue effect_types[] = {
	{GST_GL_EFFECT_IDENTITY, "Do nothing Effect", "identity"},
	{GST_GL_EFFECT_MIRROR, "Mirror Effect", "mirror"},
	{GST_GL_EFFECT_SQUEEZE, "Squeeze Effect", "squeeze"},
	{GST_GL_EFFECT_STRETCH, "Stretch Effect", "stretch"},
	{GST_GL_EFFECT_TUNNEL, "Light Tunnel Effect", "tunnel"},
	{GST_GL_EFFECT_FISHEYE, "FishEye Effect", "fisheye"},
	{GST_GL_EFFECT_TWIRL, "Twirl Effect", "twirl"},
	{GST_GL_EFFECT_BULGE, "Bulge Effect", "bulge"},
	{GST_GL_EFFECT_SQUARE, "Square Effect", "square"},
	{GST_GL_EFFECT_HEAT, "Heat Signature Effect", "heat"},
	{GST_GL_EFFECT_SEPIA, "Sepia Toning Effect", "sepia"},
	{GST_GL_EFFECT_XPRO, "Cross Processing Effect", "xpro"},
	{GST_GL_EFFECT_LUMA_XPRO, "Luma Cross Processing Effect", "lumaxpro"},
	{GST_GL_EFFECT_XRAY, "Glowing negative effect", "xray"},
	{GST_GL_EFFECT_SIN, "All Grey but Red Effect", "sin"},
	{GST_GL_EFFECT_GLOW, "Glow Lighting Effect", "glow"},
	{GST_GL_EFFECT_SOBEL, "Sobel edge detection Effect", "sobel"},
	{GST_GL_EFFECT_BLUR, "Blur with 9x9 separable convolution Effect", "blur"},
	{GST_GL_EFFECT_LAPLACIAN, "Laplacian Convolution Demo Effect", "laplacian"},
	{0, NULL, NULL}
	};
	return effect_types;
	}

	#define GST_TYPE_GL_EFFECTS_EFFECT (gst_gl_effects_effect_get_type ())
	static GType
	gst_gl_effects_effect_get_type (void)
	{
	static GType gl_effects_effect_type = 0;
	if (!gl_effects_effect_type) {
	gl_effects_effect_type =
	g_enum_register_static ("GstGLEffectsEffect",
	gst_gl_effects_get_effects ());
	}
	return gl_effects_effect_type;
	}

	static void
	gst_gl_effects_set_effect (GstGLEffects * effects, gint effect_type)
	{
	GstGLBaseFilterClass *filter_class = GST_GL_BASE_FILTER_GET_CLASS (effects);

	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;
	case GST_GL_EFFECT_STRETCH:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_stretch;
	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_TUNNEL:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_tunnel;
	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_FISHEYE:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_fisheye;
	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_TWIRL:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_twirl;
	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_BULGE:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_bulge;
	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_SQUARE:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_square;
	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_HEAT:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_heat;
	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_SEPIA:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sepia;
	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_XPRO:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_xpro;
	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_LUMA_XPRO:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_luma_xpro;
	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_SIN:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
	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_XRAY:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
	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_GLOW:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_glow;
	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_SOBEL:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sobel;
	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_BLUR:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_blur;
	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_LAPLACIAN:
	effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_laplacian;
	filter_class->supported_gl_api =
	GST_GL_API_GLES2 \| GST_GL_API_OPENGL \| GST_GL_API_OPENGL3;
	effects->current_effect = effect_type;
	break;
	default:
	g_assert_not_reached ();
	}

	effects->current_effect = effect_type;
	}

	/* init resources that need a gl context */
	static void
	gst_gl_effects_init_gl_resources (GstGLFilter * filter)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (filter);
	GstGLContext *context = GST_GL_BASE_FILTER (filter)->context;
	GstGLFuncs *gl = context->gl_vtable;
	guint internal_format;
	gint i = 0;

	for (i = 0; i < NEEDED_TEXTURES; i++) {

	if (effects->midtexture[i]) {
	gl->DeleteTextures (1, &effects->midtexture[i]);
	effects->midtexture[i] = 0;
	}

	gl->GenTextures (1, &effects->midtexture[i]);
	gl->BindTexture (GL_TEXTURE_2D, effects->midtexture[i]);
	internal_format =
	gst_gl_sized_gl_format_from_gl_format_type (context, GL_RGBA,
	GL_UNSIGNED_BYTE);
	gl->TexImage2D (GL_TEXTURE_2D, 0, internal_format,
	GST_VIDEO_INFO_WIDTH (&filter->out_info),
	GST_VIDEO_INFO_HEIGHT (&filter->out_info), 0, GL_RGBA, GL_UNSIGNED_BYTE,
	NULL);
	gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	}
	}

	/* free resources that need a gl context */
	static void
	gst_gl_effects_reset_gl_resources (GstGLFilter * filter)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (filter);
	GstGLFuncs *gl = GST_GL_BASE_FILTER (filter)->context->gl_vtable;
	gint i = 0;

	for (i = 0; i < NEEDED_TEXTURES; i++) {
	gl->DeleteTextures (1, &effects->midtexture[i]);
	effects->midtexture[i] = 0;
	}
	for (i = 0; i < GST_GL_EFFECTS_N_CURVES; i++) {
	gl->DeleteTextures (1, &effects->curve[i]);
	effects->curve[i] = 0;
	}
	}

	static void
	gst_gl_effects_class_init (GstGLEffectsClass * klass)
	{
	GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

	GST_BASE_TRANSFORM_CLASS (klass)->start = gst_gl_effects_init_resources;
	GST_BASE_TRANSFORM_CLASS (klass)->stop = gst_gl_effects_reset_resources;

	GST_GL_FILTER_CLASS (klass)->filter_texture = gst_gl_effects_filter_texture;
	GST_GL_FILTER_CLASS (klass)->display_init_cb =
	gst_gl_effects_init_gl_resources;
	GST_GL_FILTER_CLASS (klass)->display_reset_cb =
	gst_gl_effects_reset_gl_resources;
	GST_GL_FILTER_CLASS (klass)->init_fbo = gst_gl_effects_on_init_gl_context;

	klass->filter_descriptor = NULL;

	gst_element_class_set_metadata (element_class,
	"Gstreamer OpenGL Effects", "Filter/Effect/Video",
	"GL Shading Language effects",
	"Filippo Argiolas <filippo.argiolas@gmail.com>");

	GST_GL_BASE_FILTER_CLASS (klass)->supported_gl_api =
	GST_GL_API_OPENGL \| GST_GL_API_GLES2 \| GST_GL_API_OPENGL3;
	}

	static void
	gst_gl_effects_filter_class_init (GstGLEffectsClass * klass,
	const GstGLEffectsFilterDescriptor * filter_descriptor)
	{
	GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

	klass->filter_descriptor = filter_descriptor;

	gobject_class->set_property = gst_gl_effects_set_property;
	gobject_class->get_property = gst_gl_effects_get_property;

	/* if filterDescriptor is null it's a generic gleffects */
	if (!filter_descriptor) {
	g_object_class_install_property (gobject_class,
	PROP_EFFECT,
	g_param_spec_enum ("effect",
	"Effect",
	"Select which effect apply to GL video texture",
	GST_TYPE_GL_EFFECTS_EFFECT,
	GST_GL_EFFECT_IDENTITY,
	G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));
	}

	g_object_class_install_property (gobject_class,
	PROP_HSWAP,
	g_param_spec_boolean ("hswap",
	"Horizontal Swap",
	"Switch video texture left to right, useful with webcams",
	FALSE, G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));

	/* FIXME: make it work on every effect */
	if (gst_gl_effects_filters_is_property_supported (filter_descriptor,
	PROP_INVERT)) {
	g_object_class_install_property (gobject_class, PROP_INVERT,
	g_param_spec_boolean ("invert", "Invert the colors for sobel effect",
	"Invert colors to get dark edges on bright background when using sobel effect",
	FALSE, G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS));
	}
	}

	static void
	set_horizontal_swap (GstGLContext * context, gpointer data)
	{
	#if GST_GL_HAVE_OPENGL
	GstGLFuncs *gl = context->gl_vtable;

	if (gst_gl_context_get_gl_api (context) & GST_GL_API_OPENGL) {
	const gfloat mirrormatrix[16] = {
	-1.0, 0.0, 0.0, 0.0,
	0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0
	};

	gl->MatrixMode (GL_MODELVIEW);
	gl->LoadMatrixf (mirrormatrix);
	}
	#endif
	}

	static void
	gst_gl_effects_init (GstGLEffects * effects)
	{
	effects->horizontal_swap = FALSE;
	effects->invert = FALSE;
	effects->effect = gst_gl_effects_identity;
	}

	static void
	gst_gl_effects_filter_init (GstGLEffects * effects)
	{
	gst_gl_effects_set_effect (effects,
	GST_GL_EFFECTS_GET_CLASS (effects)->filter_descriptor->effect);
	}

	static void
	gst_gl_effects_ghash_func_clean (gpointer key, gpointer value, gpointer data)
	{
	GstGLShader shader = (GstGLShader ) value;
	GstGLFilter filter = (GstGLFilter ) data;

	//blocking call, wait the opengl thread has destroyed the shader
	gst_gl_context_del_shader (GST_GL_BASE_FILTER (filter)->context, shader);

	value = NULL;
	}

	static gboolean
	gst_gl_effects_reset_resources (GstBaseTransform * trans)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (trans);

	/* release shaders in the gl thread */
	g_hash_table_foreach (effects->shaderstable, gst_gl_effects_ghash_func_clean,
	effects);

	/* clean the htable without calling values destructors
	* because shaders have been released in the glthread
	* through the foreach func */
	g_hash_table_unref (effects->shaderstable);
	effects->shaderstable = NULL;

	return GST_BASE_TRANSFORM_CLASS (parent_class)->stop (trans);
	}

	static void
	gst_gl_effects_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (object);

	switch (prop_id) {
	case PROP_EFFECT:
	gst_gl_effects_set_effect (effects, g_value_get_enum (value));
	break;
	case PROP_HSWAP:
	effects->horizontal_swap = g_value_get_boolean (value);
	break;
	case PROP_INVERT:
	effects->invert = g_value_get_boolean (value);
	break;
	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}
	}

	static void
	gst_gl_effects_get_property (GObject * object, guint prop_id,
	GValue * value, GParamSpec * pspec)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (object);

	switch (prop_id) {
	case PROP_EFFECT:
	g_value_set_enum (value, effects->current_effect);
	break;
	case PROP_HSWAP:
	g_value_set_boolean (value, effects->horizontal_swap);
	break;
	case PROP_INVERT:
	g_value_set_boolean (value, effects->invert);
	break;
	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}
	}

	static gboolean
	gst_gl_effects_init_resources (GstBaseTransform * trans)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (trans);
	gint i;

	effects->shaderstable = g_hash_table_new (g_str_hash, g_str_equal);

	for (i = 0; i < NEEDED_TEXTURES; i++) {
	effects->midtexture[i] = 0;
	}
	for (i = 0; i < GST_GL_EFFECTS_N_CURVES; i++) {
	effects->curve[i] = 0;
	}

	return GST_BASE_TRANSFORM_CLASS (parent_class)->start (trans);
	}

	static gboolean
	gst_gl_effects_on_init_gl_context (GstGLFilter * filter)
	{
	return TRUE;
	}

	static gboolean
	gst_gl_effects_filter_texture (GstGLFilter * filter, guint in_tex,
	guint out_tex)
	{
	GstGLEffects *effects = GST_GL_EFFECTS (filter);

	effects->intexture = in_tex;
	effects->outtexture = out_tex;

	if (effects->horizontal_swap == TRUE)
	gst_gl_context_thread_add (GST_GL_BASE_FILTER (filter)->context,
	set_horizontal_swap, effects);

	effects->effect (effects);

	return TRUE;
	}

	GstGLShader *
	gst_gl_effects_get_fragment_shader (GstGLEffects * effects,
	const gchar * shader_name, const gchar * shader_source_gles2,
	const gchar * shader_source_opengl)
	{
	GstGLShader *shader = NULL;
	GstGLFilter *filter = GST_GL_FILTER (effects);
	GstGLContext *context = GST_GL_BASE_FILTER (filter)->context;

	shader = g_hash_table_lookup (effects->shaderstable, shader_name);

	if (!shader) {
	if (!shader && (USING_GLES2 (context) \|\| USING_OPENGL3 (context))) {
	shader = gst_gl_shader_new (context);
	if (!gst_gl_shader_compile_with_default_v_and_check (shader,
	shader_source_gles2, &filter->draw_attr_position_loc,
	&filter->draw_attr_texture_loc)) {
	/* gst gl context error is already set */
	GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND,
	("Failed to initialize %s shader, %s",
	shader_name, gst_gl_context_get_error ()), (NULL));
	gst_object_unref (shader);
	shader = NULL;
	}
	}
	#if GST_GL_HAVE_OPENGL
	if (!shader && USING_OPENGL (context)) {
	shader = gst_gl_shader_new (context);
	if (!gst_gl_shader_compile_and_check (shader,
	shader_source_opengl, GST_GL_SHADER_FRAGMENT_SOURCE)) {
	gst_gl_context_set_error (context, "Failed to initialize %s shader",
	shader_name);
	GST_ELEMENT_ERROR (effects, RESOURCE, NOT_FOUND, ("%s",
	gst_gl_context_get_error ()), (NULL));
	gst_object_unref (shader);
	shader = NULL;
	}
	}
	#endif

	if (!shader)
	return NULL;

	g_hash_table_insert (effects->shaderstable, (gchar *) shader_name, shader);
	}

	return shader;
	}

	static const GstGLEffectsFilterDescriptor *
	gst_gl_effects_filters_supported_properties (void)
	{
	/* Horizontal swap property is supported by all filters */
	static const GstGLEffectsFilterDescriptor effects[] = {
	{GST_GL_EFFECT_SOBEL, PROP_INVERT, NULL},
	{GST_GL_EFFECT_LAPLACIAN, PROP_INVERT, NULL},
	{0, 0, NULL}
	};
	return effects;
	}

	static inline gboolean
	gst_gl_effects_filters_is_property_supported (const GstGLEffectsFilterDescriptor
	* descriptor, gint property)
	{
	/* generic filter (NULL descriptor) supports all properties */
	return !descriptor \|\| (descriptor->supported_properties & property);
	}

	static const GstGLEffectsFilterDescriptor *
	gst_gl_effects_filters_descriptors (void)
	{
	static GstGLEffectsFilterDescriptor *descriptors = NULL;
	if (!descriptors) {
	const GEnumValue *e;
	const GEnumValue *effect = gst_gl_effects_get_effects ();
	const GstGLEffectsFilterDescriptor *defined;
	guint n_filters = 0, i;

	for (e = effect; NULL != e->value_nick; ++e, ++n_filters) {
	}

	descriptors = g_new0 (GstGLEffectsFilterDescriptor, n_filters + 1);
	for (i = 0; i < n_filters; ++i, ++effect) {
	descriptors[i].effect = effect->value;
	descriptors[i].filter_name = effect->value_nick;
	}

	for (defined = gst_gl_effects_filters_supported_properties ();
	0 != defined->supported_properties; ++defined) {

	for (i = 0; i < n_filters; ++i) {
	if (descriptors[i].effect == defined->effect) {
	descriptors[i].supported_properties = defined->supported_properties;
	break;
	}
	}
	if (i >= n_filters) {
	GST_WARNING ("Could not match gstgleffects-%s descriptor",
	defined->filter_name);
	}
	}
	}
	return descriptors;
	}

	gboolean
	gst_gl_effects_register_filters (GstPlugin * plugin, GstRank rank)
	{
	static volatile gsize registered = 0;

	if (g_once_init_enter (&registered)) {
	GTypeInfo info = {
	sizeof (GstGLEffectsClass),
	NULL,
	NULL,
	(GClassInitFunc) gst_gl_effects_filter_class_init,
	NULL,
	NULL,
	sizeof (GstGLEffects),
	0,
	NULL
	};
	GType generic_type =
	g_type_register_static (GST_TYPE_GL_EFFECTS, "GstGLEffectsGeneric",
	&info, 0);

	if (gst_element_register (plugin, "gleffects", rank, generic_type)) {
	const GstGLEffectsFilterDescriptor *filters;
	for (filters = gst_gl_effects_filters_descriptors ();
	NULL != filters->filter_name; ++filters) {
	gchar *name = g_strdup_printf ("gleffects_%s", filters->filter_name);
	GTypeInfo info = {
	sizeof (GstGLEffectsClass),
	NULL,
	NULL,
	(GClassInitFunc) gst_gl_effects_filter_class_init,
	NULL,
	filters,
	sizeof (GstGLEffects),
	0,
	(GInstanceInitFunc) gst_gl_effects_filter_init
	};
	GType type =
	g_type_register_static (GST_TYPE_GL_EFFECTS, name, &info, 0);
	if (!gst_element_register (plugin, name, rank, type)) {
	GST_WARNING ("Could not register %s", name);
	}
	g_free (name);
	}
	}
	g_once_init_leave (&registered, generic_type);
	}
	return registered;
	}