opengl: add element for transforming video geometry

* add graphene as soft dependency for linear algebra

configure.ac

@@ -284,6 +284,18 @@ if test "x$BUILD_EXAMPLES" = "xyes"; then
 fi
 AM_CONDITIONAL(HAVE_XCOMPOSITE, test "x$HAVE_XCOMPOSITE" = "xyes")
 
+dnl graphene-1.0 is optional and used in gltransformation
+HAVE_GRAPHENE=NO
+PKG_CHECK_MODULES(GRAPHENE, graphene-1.0, HAVE_GRAPHENE=yes, HAVE_GRAPHENE=no)
+if test "x$HAVE_GRAPHENE" = "xyes"; then
+  AC_DEFINE(HAVE_GRAPHENE, [1] , [Use graphene])
+fi
+AC_SUBST(HAVE_GRAPHENE)
+AC_SUBST(GRAPHENE_LIBS)
+AC_SUBST(GRAPHENE_CFLAGS)
+AM_CONDITIONAL(HAVE_GRAPHENE, test "x$HAVE_GRAPHENE" = "xyes")
+
+
 dnl sdl is optional and used in examples
 HAVE_SDL=NO
 if test "x$BUILD_EXAMPLES" = "xyes"; then

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

@@ -1611,6 +1611,19 @@ GST_IS_ZBAR_CLASS
 GST_TYPE_ZBAR
 </SECTION>
 
+<SECTION>
+<FILE>element-gltransformation</FILE>
+<TITLE>gltransformation</TITLE>
+GstGLTransformation
+<SUBSECTION Standard>
+GstGLTransformationClass
+GST_GL_TRANSFORMATION
+GST_GL_TRANSFORMATION_CLASS
+GST_IS_GL_TRANSFORMATION
+GST_IS_GL_TRANSFORMATION_CLASS
+GST_TYPE_GL_TRANSFORMATION
+</SECTION>
+
 # gst-libs
 
 <SECTION>

ext/gl/Makefile.am

@@ -76,6 +76,12 @@ libgstopengl_la_SOURCES = \
 	gstglcolorscale.h \
 	$(OPENGL_SOURCES)
 
+if HAVE_GRAPHENE
+libgstopengl_la_SOURCES += \
+	gstgltransformation.c \
+	gstgltransformation.h
+endif
+
 # check order of CFLAGS and LIBS, shouldn't the order be the other way around
 # (like in AM_CFLAGS)?
 libgstopengl_la_CFLAGS = \
@@ -85,7 +91,8 @@ libgstopengl_la_CFLAGS = \
 	$(GST_BASE_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GL_CFLAGS) \
-	$(LIBPNG_CFLAGS)
+	$(LIBPNG_CFLAGS) \
+	$(GRAPHENE_CFLAGS)
 
 libgstopengl_la_LIBADD = \
 	$(top_builddir)/gst-libs/gst/gl/libgstgl-$(GST_API_VERSION).la \
@@ -95,7 +102,8 @@ libgstopengl_la_LIBADD = \
 	$(GL_LIBS) \
 	$(LIBPNG_LIBS) \
 	$(JPEG_LIBS) \
-	$(LIBM)
+	$(LIBM) \
+	$(GRAPHENE_LIBS)
 
 libgstopengl_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 libgstopengl_la_LIBTOOLFLAGS = $(GST_PLUGIN_LIBTOOLFLAGS)

ext/gl/gstgltransformation.c

@@ -0,0 +1,476 @@
+/*
+ * GStreamer
+ * Copyright (C) 2014 Lubosz Sarnecki <lubosz@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-gltransformation
+ *
+ * Transforms video on the GPU.
+ *
+ * <refsect2>
+ * <title>Examples</title>
+ * |[
+ * gst-launch gltestsrc ! gltransformation rotation-z=45 ! glimagesink
+ * ]| A pipeline to rotate by 45 degrees
+ * |[
+ * gst-launch gltestsrc ! gltransformation translation-x=0.5 ! glimagesink
+ * ]| Translate the video by 0.5
+ * |[
+ * gst-launch gltestsrc ! gltransformation scale-y=0.5 scale-x=0.5 ! glimagesink
+ * ]| Resize the video by 0.5
+ * |[
+ * gst-launch gltestsrc ! gltransformation rotation-x=-45 ortho=True ! glimagesink
+ * ]| Rotate the video around the X-Axis by -45° with an orthographic projection
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gl/gstglapi.h>
+#include "gstgltransformation.h"
+
+#define GST_CAT_DEFAULT gst_gl_transformation_debug
+GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
+
+enum
+{
+  PROP_0,
+  PROP_FOVY,
+  PROP_ORTHO,
+  PROP_TRANSLATION_X,
+  PROP_TRANSLATION_Y,
+  PROP_TRANSLATION_Z,
+  PROP_ROTATION_X,
+  PROP_ROTATION_Y,
+  PROP_ROTATION_Z,
+  PROP_SCALE_X,
+  PROP_SCALE_Y
+};
+
+#define DEBUG_INIT \
+    GST_DEBUG_CATEGORY_INIT (gst_gl_transformation_debug, "gltransformation", 0, "gltransformation element");
+
+G_DEFINE_TYPE_WITH_CODE (GstGLTransformation, gst_gl_transformation,
+    GST_TYPE_GL_FILTER, DEBUG_INIT);
+
+static void gst_gl_transformation_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_gl_transformation_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+static gboolean gst_gl_transformation_set_caps (GstGLFilter * filter,
+    GstCaps * incaps, GstCaps * outcaps);
+
+static void gst_gl_transformation_reset (GstGLFilter * filter);
+static gboolean gst_gl_transformation_init_shader (GstGLFilter * filter);
+static void gst_gl_transformation_callback (gpointer stuff);
+static void gst_gl_transformation_build_mvp (GstGLTransformation *
+    transformation);
+
+static gboolean gst_gl_transformation_filter_texture (GstGLFilter * filter,
+    guint in_tex, guint out_tex);
+
+/* vertex source */
+static const gchar *cube_v_src =
+    "attribute vec4 position;                     \n"
+    "attribute vec2 uv;                           \n"
+    "uniform mat4 mvp;                            \n"
+    "varying vec2 out_uv;                         \n"
+    "void main()                                  \n"
+    "{                                            \n"
+    "   gl_Position = mvp * position;             \n"
+    "   out_uv = uv;                              \n"
+    "}                                            \n";
+
+/* fragment source */
+static const gchar *cube_f_src =
+    "#ifdef GL_ES                                 \n"
+    "  precision mediump float;                   \n"
+    "#endif                                       \n"
+    "varying vec2 out_uv;                         \n"
+    "uniform sampler2D texture;                   \n"
+    "void main()                                  \n"
+    "{                                            \n"
+    "  gl_FragColor = texture2D (texture, out_uv);\n"
+    "}                                            \n";
+
+static void
+gst_gl_transformation_class_init (GstGLTransformationClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *element_class;
+
+  gobject_class = (GObjectClass *) klass;
+  element_class = GST_ELEMENT_CLASS (klass);
+
+  gobject_class->set_property = gst_gl_transformation_set_property;
+  gobject_class->get_property = gst_gl_transformation_get_property;
+
+  GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_transformation_init_shader;
+  GST_GL_FILTER_CLASS (klass)->onReset = gst_gl_transformation_reset;
+  GST_GL_FILTER_CLASS (klass)->set_caps = gst_gl_transformation_set_caps;
+  GST_GL_FILTER_CLASS (klass)->filter_texture =
+      gst_gl_transformation_filter_texture;
+
+  g_object_class_install_property (gobject_class, PROP_FOVY,
+      g_param_spec_float ("fovy", "Fovy", "Field of view angle in degrees",
+          0.0, G_MAXFLOAT, 90.0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_ORTHO,
+      g_param_spec_boolean ("ortho", "Orthographic",
+          "Use orthographic projection", FALSE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  /* Rotation */
+  g_object_class_install_property (gobject_class, PROP_ROTATION_X,
+      g_param_spec_float ("rotation-x", "X Rotation",
+          "Rotates the video around the X-Axis in degrees.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_ROTATION_Y,
+      g_param_spec_float ("rotation-y", "Y Rotation",
+          "Rotates the video around the Y-Axis in degrees.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_ROTATION_Z,
+      g_param_spec_float ("rotation-z", "Z Rotation",
+          "Rotates the video around the Z-Axis in degrees.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  /* Translation */
+  g_object_class_install_property (gobject_class, PROP_TRANSLATION_X,
+      g_param_spec_float ("translation-x", "X Translation",
+          "Translates the video at the X-Axis.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_TRANSLATION_Y,
+      g_param_spec_float ("translation-y", "Y Translation",
+          "Translates the video at the Y-Axis.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_TRANSLATION_Z,
+      g_param_spec_float ("translation-z", "Z Translation",
+          "Translates the video at the Z-Axis.",
+          -G_MAXFLOAT, G_MAXFLOAT, 0.0,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  /* Scale */
+  g_object_class_install_property (gobject_class, PROP_SCALE_X,
+      g_param_spec_float ("scale-x", "X Scale",
+          "Scale multiplierer for the X-Axis.",
+          0.0, G_MAXFLOAT, 1.0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_SCALE_Y,
+      g_param_spec_float ("scale-y", "Y Scale",
+          "Scale multiplierer for the Y-Axis.",
+          0.0, G_MAXFLOAT, 1.0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  gst_element_class_set_metadata (element_class, "OpenGL transformation filter",
+      "Filter/Effect/Video", "Transform video on the GPU",
+      "Lubosz Sarnecki <lubosz@gmail.com>");
+}
+
+static void
+gst_gl_transformation_init (GstGLTransformation * filter)
+{
+  filter->shader = NULL;
+  filter->fovy = 90;
+  filter->aspect = 0;
+  filter->znear = 0.1;
+  filter->zfar = 100;
+
+  filter->xscale = 1.0;
+  filter->yscale = 1.0;
+
+  filter->in_tex = 0;
+
+  gst_gl_transformation_build_mvp (filter);
+}
+
+static void
+gst_gl_transformation_build_mvp (GstGLTransformation * transformation)
+{
+  graphene_point3d_t translation_vector =
+      GRAPHENE_POINT3D_INIT (transformation->xtranslation,
+      transformation->ytranslation,
+      transformation->ztranslation);
+
+  graphene_matrix_t model_matrix;
+  graphene_matrix_t projection_matrix;
+  graphene_matrix_t view_matrix;
+  graphene_matrix_t vp_matrix;
+
+  graphene_vec3_t eye;
+  graphene_vec3_t center;
+  graphene_vec3_t up;
+
+  graphene_vec3_init (&eye, 0.f, 0.f, 1.f);
+  graphene_vec3_init (&center, 0.f, 0.f, 0.f);
+  graphene_vec3_init (&up, 0.f, 1.f, 0.f);
+
+  graphene_matrix_init_rotate (&model_matrix,
+      transformation->xrotation, graphene_vec3_x_axis ());
+  graphene_matrix_rotate (&model_matrix,
+      transformation->yrotation, graphene_vec3_y_axis ());
+  graphene_matrix_rotate (&model_matrix,
+      transformation->zrotation, graphene_vec3_z_axis ());
+  graphene_matrix_scale (&model_matrix,
+      transformation->xscale, transformation->yscale, 1.0f);
+  graphene_matrix_translate (&model_matrix, &translation_vector);
+
+  if (transformation->ortho) {
+    graphene_matrix_init_ortho (&projection_matrix,
+        -transformation->aspect, transformation->aspect,
+        -1, 1, transformation->znear, transformation->zfar);
+  } else {
+    graphene_matrix_init_perspective (&projection_matrix,
+        transformation->fovy,
+        transformation->aspect, transformation->znear, transformation->zfar);
+  }
+
+  graphene_matrix_init_look_at (&view_matrix, &eye, &center, &up);
+
+  graphene_matrix_multiply (&projection_matrix, &view_matrix, &vp_matrix);
+  graphene_matrix_multiply (&vp_matrix, &model_matrix,
+      &transformation->mvp_matrix);
+}
+
+static void
+gst_gl_transformation_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstGLTransformation *filter = GST_GL_TRANSFORMATION (object);
+
+  switch (prop_id) {
+    case PROP_FOVY:
+      filter->fovy = g_value_get_float (value);
+      break;
+    case PROP_ORTHO:
+      filter->ortho = g_value_get_boolean (value);
+      break;
+    case PROP_TRANSLATION_X:
+      filter->xtranslation = g_value_get_float (value);
+      break;
+    case PROP_TRANSLATION_Y:
+      filter->ytranslation = g_value_get_float (value);
+      break;
+    case PROP_TRANSLATION_Z:
+      filter->ztranslation = g_value_get_float (value);
+      break;
+    case PROP_ROTATION_X:
+      filter->xrotation = g_value_get_float (value);
+      break;
+    case PROP_ROTATION_Y:
+      filter->yrotation = g_value_get_float (value);
+      break;
+    case PROP_ROTATION_Z:
+      filter->zrotation = g_value_get_float (value);
+      break;
+    case PROP_SCALE_X:
+      filter->xscale = g_value_get_float (value);
+      break;
+    case PROP_SCALE_Y:
+      filter->yscale = g_value_get_float (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+  gst_gl_transformation_build_mvp (filter);
+}
+
+static void
+gst_gl_transformation_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstGLTransformation *filter = GST_GL_TRANSFORMATION (object);
+
+  switch (prop_id) {
+    case PROP_FOVY:
+      g_value_set_float (value, filter->fovy);
+      break;
+    case PROP_ORTHO:
+      g_value_set_boolean (value, filter->ortho);
+      break;
+    case PROP_TRANSLATION_X:
+      g_value_set_float (value, filter->xtranslation);
+      break;
+    case PROP_TRANSLATION_Y:
+      g_value_set_float (value, filter->ytranslation);
+      break;
+    case PROP_TRANSLATION_Z:
+      g_value_set_float (value, filter->ztranslation);
+      break;
+    case PROP_ROTATION_X:
+      g_value_set_float (value, filter->xrotation);
+      break;
+    case PROP_ROTATION_Y:
+      g_value_set_float (value, filter->yrotation);
+      break;
+    case PROP_ROTATION_Z:
+      g_value_set_float (value, filter->zrotation);
+      break;
+    case PROP_SCALE_X:
+      g_value_set_float (value, filter->xscale);
+      break;
+    case PROP_SCALE_Y:
+      g_value_set_float (value, filter->yscale);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static gboolean
+gst_gl_transformation_set_caps (GstGLFilter * filter, GstCaps * incaps,
+    GstCaps * outcaps)
+{
+  GstGLTransformation *transformation = GST_GL_TRANSFORMATION (filter);
+
+  transformation->aspect =
+      (gdouble) GST_VIDEO_INFO_WIDTH (&filter->out_info) /
+      (gdouble) GST_VIDEO_INFO_HEIGHT (&filter->out_info);
+
+  gst_gl_transformation_build_mvp (transformation);
+
+  return TRUE;
+}
+
+static void
+gst_gl_transformation_reset (GstGLFilter * filter)
+{
+  GstGLTransformation *transformation = GST_GL_TRANSFORMATION (filter);
+
+  /* blocking call, wait until the opengl thread has destroyed the shader */
+  if (transformation->shader)
+    gst_gl_context_del_shader (filter->context, transformation->shader);
+  transformation->shader = NULL;
+}
+
+static gboolean
+gst_gl_transformation_init_shader (GstGLFilter * filter)
+{
+  GstGLTransformation *transformation = GST_GL_TRANSFORMATION (filter);
+
+  if (gst_gl_context_get_gl_api (filter->context)) {
+    /* blocking call, wait until the opengl thread has compiled the shader */
+    return gst_gl_context_gen_shader (filter->context, cube_v_src, cube_f_src,
+        &transformation->shader);
+  }
+  return TRUE;
+}
+
+static gboolean
+gst_gl_transformation_filter_texture (GstGLFilter * filter, guint in_tex,
+    guint out_tex)
+{
+  GstGLTransformation *transformation = GST_GL_TRANSFORMATION (filter);
+
+  transformation->in_tex = in_tex;
+
+  /* blocking call, use a FBO */
+  gst_gl_context_use_fbo_v2 (filter->context,
+      GST_VIDEO_INFO_WIDTH (&filter->out_info),
+      GST_VIDEO_INFO_HEIGHT (&filter->out_info),
+      filter->fbo, filter->depthbuffer,
+      out_tex, gst_gl_transformation_callback, (gpointer) transformation);
+
+  return TRUE;
+}
+
+static void
+gst_gl_transformation_callback (gpointer stuff)
+{
+  GstGLFilter *filter = GST_GL_FILTER (stuff);
+  GstGLTransformation *transformation = GST_GL_TRANSFORMATION (filter);
+  GstGLFuncs *gl = filter->context->gl_vtable;
+
+/* *INDENT-OFF* */
+
+  const GLfloat positions[] = {
+     -transformation->aspect,  1.0,  0.0, 1.0,
+      transformation->aspect,  1.0,  0.0, 1.0,
+      transformation->aspect, -1.0,  0.0, 1.0,
+     -transformation->aspect, -1.0,  0.0, 1.0,
+  };
+
+  const GLfloat texture_coordinates[] = {
+     0.0,  1.0,
+     1.0,  1.0,
+     1.0,  0.0,
+     0.0,  0.0,
+  };
+
+/* *INDENT-ON* */
+
+  GLushort indices[] = { 0, 1, 2, 3, 0 };
+
+  GLfloat temp_matrix[16];
+
+  GLint attr_position_loc = 0;
+  GLint attr_texture_loc = 0;
+
+  gst_gl_context_clear_shader (filter->context);
+  gl->BindTexture (GL_TEXTURE_2D, 0);
+
+  gl->ClearColor (0.f, 0.f, 0.f, 0.f);
+  gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  gst_gl_shader_use (transformation->shader);
+
+  attr_position_loc =
+      gst_gl_shader_get_attribute_location (transformation->shader, "position");
+
+  attr_texture_loc =
+      gst_gl_shader_get_attribute_location (transformation->shader, "uv");
+
+  /* Load the vertex position */
+  gl->VertexAttribPointer (attr_position_loc, 4, GL_FLOAT,
+      GL_FALSE, 0, positions);
+
+  /* Load the texture coordinate */
+  gl->VertexAttribPointer (attr_texture_loc, 2, GL_FLOAT,
+      GL_FALSE, 0, texture_coordinates);
+
+  gl->EnableVertexAttribArray (attr_position_loc);
+  gl->EnableVertexAttribArray (attr_texture_loc);
+
+  gl->ActiveTexture (GL_TEXTURE0);
+  gl->BindTexture (GL_TEXTURE_2D, transformation->in_tex);
+  gst_gl_shader_set_uniform_1i (transformation->shader, "texture", 0);
+
+  graphene_matrix_to_float (&transformation->mvp_matrix, temp_matrix);
+  gst_gl_shader_set_uniform_matrix_4fv (transformation->shader, "mvp",
+      1, GL_FALSE, temp_matrix);
+
+  gl->DrawElements (GL_TRIANGLE_STRIP, 5, GL_UNSIGNED_SHORT, indices);
+
+  gl->DisableVertexAttribArray (attr_position_loc);
+  gl->DisableVertexAttribArray (attr_texture_loc);
+
+  gst_gl_context_clear_shader (filter->context);
+}

ext/gl/gstgltransformation.h

@@ -0,0 +1,77 @@
+/*
+ * GStreamer
+ * Copyright (C) 2014 Lubosz Sarnecki <lubosz@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.
+ */
+
+#ifndef _GST_GL_TRANSFORMATION_H_
+#define _GST_GL_TRANSFORMATION_H_
+
+#include <gst/gl/gstglfilter.h>
+#include <graphene-1.0/graphene.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_GL_TRANSFORMATION            (gst_gl_transformation_get_type())
+#define GST_GL_TRANSFORMATION(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_GL_TRANSFORMATION,GstGLTransformation))
+#define GST_IS_GL_TRANSFORMATION(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_GL_TRANSFORMATION))
+#define GST_GL_TRANSFORMATION_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass) ,GST_TYPE_GL_TRANSFORMATION,GstGLTransformationClass))
+#define GST_IS_GL_TRANSFORMATION_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) ,GST_TYPE_GL_TRANSFORMATION))
+#define GST_GL_TRANSFORMATION_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj) ,GST_TYPE_GL_TRANSFORMATION,GstGLTransformationClass))
+
+typedef struct _GstGLTransformation GstGLTransformation;
+typedef struct _GstGLTransformationClass GstGLTransformationClass;
+
+struct _GstGLTransformation
+{
+    GstGLFilter filter;
+
+    GstGLShader *shader;
+
+    guint in_tex;
+
+    gfloat xrotation;
+    gfloat yrotation;
+    gfloat zrotation;
+
+    gfloat xscale;
+    gfloat yscale;
+
+    gfloat xtranslation;
+    gfloat ytranslation;
+    gfloat ztranslation;
+
+    /* perspective */
+    gfloat fovy;
+    gfloat aspect;
+    gfloat znear;
+    gfloat zfar;
+    gboolean ortho;
+
+    graphene_matrix_t mvp_matrix;
+};
+
+struct _GstGLTransformationClass
+{
+    GstGLFilterClass filter_class;
+};
+
+GType gst_gl_transformation_get_type (void);
+
+G_END_DECLS
+
+#endif /* _GST_GL_TRANSFORMATION_H_ */

ext/gl/gstopengl.c

@@ -48,6 +48,9 @@
 #include "gstglfiltercube.h"
 #include "gstgleffects.h"
 #include "gstglcolorscale.h"
+#if HAVE_GRAPHENE
+#include "gstgltransformation.h"
+#endif
 
 #if GST_GL_HAVE_OPENGL
 #include "gstgltestsrc.h"
@@ -97,7 +100,12 @@ plugin_init (GstPlugin * plugin)
           GST_RANK_NONE, GST_TYPE_GL_FILTER_CUBE)) {
     return FALSE;
   }
-
+#if HAVE_GRAPHENE
+  if (!gst_element_register (plugin, "gltransformation",
+          GST_RANK_NONE, GST_TYPE_GL_TRANSFORMATION)) {
+    return FALSE;
+  }
+#endif
   if (!gst_element_register (plugin, "gleffects",
           GST_RANK_NONE, gst_gl_effects_get_type ())) {
     return FALSE;