gst/debugutils/gstnavigationtest.c - imx-gst-plugins-good - Git at Google

 /* GStreamer
  * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
  * Copyright (C) <2003> David Schleef <ds@schleef.org>
  *
  * 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., 59 Temple Place - Suite 330,
  * Boston, MA 02111-1307, USA.
  */

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

 #include "gstnavigationtest.h"
 #include <string.h>
 #include <math.h>

 #include <gst/video/video.h>

 #ifdef _MSC_VER
 #define rint(x) (floor((x)+0.5))
 #endif

 GST_DEBUG_CATEGORY_STATIC (navigationtest_debug);
 #define GST_CAT_DEFAULT navigationtest_debug

 static const GstElementDetails navigationtest_details =
 GST_ELEMENT_DETAILS ("Video navigation test",
     "Filter/Effect/Video",
     "Handle navigation events showing a black square following mouse pointer",
     "David Schleef <ds@schleef.org>");

 static GstStaticPadTemplate gst_navigationtest_src_template =
 GST_STATIC_PAD_TEMPLATE ("src",
     GST_PAD_SRC,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
     );

 static GstStaticPadTemplate gst_navigationtest_sink_template =
 GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
     );

 static GstVideoFilterClass *parent_class = NULL;

 static gboolean
 gst_navigationtest_handle_src_event (GstPad * pad, GstEvent * event)
 {
   GstNavigationtest *navtest;
   const gchar *type;

   navtest = GST_NAVIGATIONTEST (GST_PAD_PARENT (pad));

   switch (GST_EVENT_TYPE (event)) {
     case GST_EVENT_NAVIGATION:
     {
       const GstStructure *s = gst_event_get_structure (event);
       gint fps_n, fps_d;

       fps_n = gst_value_get_fraction_numerator ((&navtest->framerate));
       fps_d = gst_value_get_fraction_denominator ((&navtest->framerate));

       type = gst_structure_get_string (s, "event");
       if (g_str_equal (type, "mouse-move")) {
         gst_structure_get_double (s, "pointer_x", &navtest->x);
         gst_structure_get_double (s, "pointer_y", &navtest->y);
       } else if (g_str_equal (type, "mouse-button-press")) {
         ButtonClick *click = g_new (ButtonClick, 1);

         gst_structure_get_double (s, "pointer_x", &click->x);
         gst_structure_get_double (s, "pointer_y", &click->y);
         click->images_left = (fps_n + fps_d - 1) / fps_d;
         /* green */
         click->cy = 150;
         click->cu = 46;
         click->cv = 21;
         navtest->clicks = g_slist_prepend (navtest->clicks, click);
       } else if (g_str_equal (type, "mouse-button-release")) {
         ButtonClick *click = g_new (ButtonClick, 1);

         gst_structure_get_double (s, "pointer_x", &click->x);
         gst_structure_get_double (s, "pointer_y", &click->y);
         click->images_left = (fps_n + fps_d - 1) / fps_d;
         /* red */
         click->cy = 76;
         click->cu = 85;
         click->cv = 255;
         navtest->clicks = g_slist_prepend (navtest->clicks, click);
       }
       break;
     }
     default:
       break;
   }
   return gst_pad_event_default (pad, event);
 }

 /* Useful macros */
 #define GST_VIDEO_I420_Y_ROWSTRIDE(width) (GST_ROUND_UP_4(width))
 #define GST_VIDEO_I420_U_ROWSTRIDE(width) (GST_ROUND_UP_8(width)/2)
 #define GST_VIDEO_I420_V_ROWSTRIDE(width) ((GST_ROUND_UP_8(GST_VIDEO_I420_Y_ROWSTRIDE(width)))/2)

 #define GST_VIDEO_I420_Y_OFFSET(w,h) (0)
 #define GST_VIDEO_I420_U_OFFSET(w,h) (GST_VIDEO_I420_Y_OFFSET(w,h)+(GST_VIDEO_I420_Y_ROWSTRIDE(w)*GST_ROUND_UP_2(h)))
 #define GST_VIDEO_I420_V_OFFSET(w,h) (GST_VIDEO_I420_U_OFFSET(w,h)+(GST_VIDEO_I420_U_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

 #define GST_VIDEO_I420_SIZE(w,h)     (GST_VIDEO_I420_V_OFFSET(w,h)+(GST_VIDEO_I420_V_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

 static gboolean
 gst_navigationtest_get_unit_size (GstBaseTransform * btrans, GstCaps * caps,
     guint * size)
 {
   GstNavigationtest *navtest;
   GstStructure *structure;
   gboolean ret = FALSE;
   gint width, height;

   navtest = GST_NAVIGATIONTEST (btrans);

   structure = gst_caps_get_structure (caps, 0);

   if (gst_structure_get_int (structure, "width", &width) &&
       gst_structure_get_int (structure, "height", &height)) {
     *size = GST_VIDEO_I420_SIZE (width, height);
     ret = TRUE;
     GST_DEBUG_OBJECT (navtest, "our frame size is %d bytes (%dx%d)", *size,
         width, height);
   }

   return ret;
 }

 static gboolean
 gst_navigationtest_set_caps (GstBaseTransform * btrans, GstCaps * incaps,
     GstCaps * outcaps)
 {
   GstNavigationtest *navtest = GST_NAVIGATIONTEST (btrans);
   gboolean ret = FALSE;
   GstStructure *structure;

   structure = gst_caps_get_structure (incaps, 0);

   if (gst_structure_get_int (structure, "width", &navtest->width) &&
       gst_structure_get_int (structure, "height", &navtest->height)) {
     const GValue *framerate;

     framerate = gst_structure_get_value (structure, "framerate");
     if (framerate && GST_VALUE_HOLDS_FRACTION (framerate)) {
       g_value_copy (framerate, &navtest->framerate);
       ret = TRUE;
     }
   }

   return ret;
 }

 static void
 draw_box_planar411 (guint8 * dest, int width, int height, int x, int y,
     guint8 colory, guint8 coloru, guint8 colorv)
 {
   int x1, x2, y1, y2;
   guint8 *d = dest;

   if (x < 0 || y < 0 || x >= width || y >= height)
     return;

   x1 = MAX (x - 5, 0);
   x2 = MIN (x + 5, width);
   y1 = MAX (y - 5, 0);
   y2 = MIN (y + 5, height);

   for (y = y1; y < y2; y++) {
     for (x = x1; x < x2; x++) {
       ((guint8 *) d)[y * GST_VIDEO_I420_Y_ROWSTRIDE (width) + x] = colory;
     }
   }

   d = dest + GST_VIDEO_I420_U_OFFSET (width, height);
   x1 /= 2;
   x2 /= 2;
   y1 /= 2;
   y2 /= 2;
   for (y = y1; y < y2; y++) {
     for (x = x1; x < x2; x++) {
       ((guint8 *) d)[y * GST_VIDEO_I420_U_ROWSTRIDE (width) + x] = coloru;
     }
   }

   d = dest + GST_VIDEO_I420_V_OFFSET (width, height);
   for (y = y1; y < y2; y++) {
     for (x = x1; x < x2; x++) {
       ((guint8 *) d)[y * GST_VIDEO_I420_V_ROWSTRIDE (width) + x] = colorv;
     }
   }
 }

 static GstFlowReturn
 gst_navigationtest_transform (GstBaseTransform * trans, GstBuffer * in,
     GstBuffer * out)
 {
   GstNavigationtest *navtest = GST_NAVIGATIONTEST (trans);
   GSList *walk;
   GstFlowReturn ret = GST_FLOW_OK;

   /* do something interesting here.  This simply copies the source
    * to the destination. */
   gst_buffer_copy_metadata (out, in, GST_BUFFER_COPY_TIMESTAMPS);

   memcpy (GST_BUFFER_DATA (out), GST_BUFFER_DATA (in),
       MIN (GST_BUFFER_SIZE (in), GST_BUFFER_SIZE (out)));

   walk = navtest->clicks;
   while (walk) {
     ButtonClick *click = walk->data;

     walk = g_slist_next (walk);
     draw_box_planar411 (GST_BUFFER_DATA (out), navtest->width, navtest->height,
         rint (click->x), rint (click->y), click->cy, click->cu, click->cv);
     if (--click->images_left < 1) {
       navtest->clicks = g_slist_remove (navtest->clicks, click);
       g_free (click);
     }
   }
   draw_box_planar411 (GST_BUFFER_DATA (out), navtest->width, navtest->height,
       rint (navtest->x), rint (navtest->y), 0, 128, 128);

   return ret;
 }

 static GstStateChangeReturn
 gst_navigationtest_change_state (GstElement * element,
     GstStateChange transition)
 {
   GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
   GstNavigationtest *navtest = GST_NAVIGATIONTEST (element);

   if (GST_ELEMENT_CLASS (parent_class)->change_state)
     ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);

   /* downwards state changes */
   switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:
     {
       g_slist_foreach (navtest->clicks, (GFunc) g_free, NULL);
       g_slist_free (navtest->clicks);
       navtest->clicks = NULL;
       break;
     }
     default:
       break;
   }

   return ret;
 }

 static void
 gst_navigationtest_base_init (gpointer g_class)
 {
   GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

   gst_element_class_set_details (element_class, &navigationtest_details);

   gst_element_class_add_pad_template (element_class,
       gst_static_pad_template_get (&gst_navigationtest_sink_template));
   gst_element_class_add_pad_template (element_class,
       gst_static_pad_template_get (&gst_navigationtest_src_template));
 }

 static void
 gst_navigationtest_class_init (gpointer klass, gpointer class_data)
 {
   GstElementClass *element_class;
   GstBaseTransformClass *trans_class;

   element_class = (GstElementClass *) klass;
   trans_class = (GstBaseTransformClass *) klass;

   parent_class = g_type_class_peek_parent (klass);

   element_class->change_state =
       GST_DEBUG_FUNCPTR (gst_navigationtest_change_state);

   trans_class->set_caps = GST_DEBUG_FUNCPTR (gst_navigationtest_set_caps);
   trans_class->get_unit_size =
       GST_DEBUG_FUNCPTR (gst_navigationtest_get_unit_size);
   trans_class->transform = GST_DEBUG_FUNCPTR (gst_navigationtest_transform);
 }

 static void
 gst_navigationtest_init (GTypeInstance * instance, gpointer g_class)
 {
   GstNavigationtest *navtest = GST_NAVIGATIONTEST (instance);
   GstBaseTransform *btrans = GST_BASE_TRANSFORM (instance);

   gst_pad_set_event_function (btrans->srcpad,
       GST_DEBUG_FUNCPTR (gst_navigationtest_handle_src_event));

   navtest->x = -1;
   navtest->y = -1;
   g_value_init (&navtest->framerate, GST_TYPE_FRACTION);
 }

 GType
 gst_navigationtest_get_type (void)
 {
   static GType navigationtest_type = 0;

   if (!navigationtest_type) {
     static const GTypeInfo navigationtest_info = {
       sizeof (GstNavigationtestClass),
       gst_navigationtest_base_init,
       NULL,
       gst_navigationtest_class_init,
       NULL,
       NULL,
       sizeof (GstNavigationtest),
       0,
       gst_navigationtest_init,
     };

     navigationtest_type = g_type_register_static (GST_TYPE_VIDEO_FILTER,
         "GstNavigationtest", &navigationtest_info, 0);
   }
   return navigationtest_type;
 }

 static gboolean
 plugin_init (GstPlugin * plugin)
 {
   GST_DEBUG_CATEGORY_INIT (navigationtest_debug, "navigationtest", 0,
       "navigationtest");

   return gst_element_register (plugin, "navigationtest", GST_RANK_NONE,
       GST_TYPE_NAVIGATIONTEST);
 }

 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
     GST_VERSION_MINOR,
     "navigationtest",
     "Template for a video filter",
     plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
	/* GStreamer
	* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
	* Copyright (C) <2003> David Schleef <ds@schleef.org>
	*
	* 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., 59 Temple Place - Suite 330,
	* Boston, MA 02111-1307, USA.
	*/

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

	#include "gstnavigationtest.h"
	#include <string.h>
	#include <math.h>

	#include <gst/video/video.h>

	#ifdef _MSC_VER
	#define rint(x) (floor((x)+0.5))
	#endif

	GST_DEBUG_CATEGORY_STATIC (navigationtest_debug);
	#define GST_CAT_DEFAULT navigationtest_debug

	static const GstElementDetails navigationtest_details =
	GST_ELEMENT_DETAILS ("Video navigation test",
	"Filter/Effect/Video",
	"Handle navigation events showing a black square following mouse pointer",
	"David Schleef <ds@schleef.org>");

	static GstStaticPadTemplate gst_navigationtest_src_template =
	GST_STATIC_PAD_TEMPLATE ("src",
	GST_PAD_SRC,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
	);

	static GstStaticPadTemplate gst_navigationtest_sink_template =
	GST_STATIC_PAD_TEMPLATE ("sink",
	GST_PAD_SINK,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
	);

	static GstVideoFilterClass *parent_class = NULL;

	static gboolean
	gst_navigationtest_handle_src_event (GstPad * pad, GstEvent * event)
	{
	GstNavigationtest *navtest;
	const gchar *type;

	navtest = GST_NAVIGATIONTEST (GST_PAD_PARENT (pad));

	switch (GST_EVENT_TYPE (event)) {
	case GST_EVENT_NAVIGATION:
	{
	const GstStructure *s = gst_event_get_structure (event);
	gint fps_n, fps_d;

	fps_n = gst_value_get_fraction_numerator ((&navtest->framerate));
	fps_d = gst_value_get_fraction_denominator ((&navtest->framerate));

	type = gst_structure_get_string (s, "event");
	if (g_str_equal (type, "mouse-move")) {
	gst_structure_get_double (s, "pointer_x", &navtest->x);
	gst_structure_get_double (s, "pointer_y", &navtest->y);
	} else if (g_str_equal (type, "mouse-button-press")) {
	ButtonClick *click = g_new (ButtonClick, 1);

	gst_structure_get_double (s, "pointer_x", &click->x);
	gst_structure_get_double (s, "pointer_y", &click->y);
	click->images_left = (fps_n + fps_d - 1) / fps_d;
	/* green */
	click->cy = 150;
	click->cu = 46;
	click->cv = 21;
	navtest->clicks = g_slist_prepend (navtest->clicks, click);
	} else if (g_str_equal (type, "mouse-button-release")) {
	ButtonClick *click = g_new (ButtonClick, 1);

	gst_structure_get_double (s, "pointer_x", &click->x);
	gst_structure_get_double (s, "pointer_y", &click->y);
	click->images_left = (fps_n + fps_d - 1) / fps_d;
	/* red */
	click->cy = 76;
	click->cu = 85;
	click->cv = 255;
	navtest->clicks = g_slist_prepend (navtest->clicks, click);
	}
	break;
	}
	default:
	break;
	}
	return gst_pad_event_default (pad, event);
	}

	/* Useful macros */
	#define GST_VIDEO_I420_Y_ROWSTRIDE(width) (GST_ROUND_UP_4(width))
	#define GST_VIDEO_I420_U_ROWSTRIDE(width) (GST_ROUND_UP_8(width)/2)
	#define GST_VIDEO_I420_V_ROWSTRIDE(width) ((GST_ROUND_UP_8(GST_VIDEO_I420_Y_ROWSTRIDE(width)))/2)

	#define GST_VIDEO_I420_Y_OFFSET(w,h) (0)
	#define GST_VIDEO_I420_U_OFFSET(w,h) (GST_VIDEO_I420_Y_OFFSET(w,h)+(GST_VIDEO_I420_Y_ROWSTRIDE(w)*GST_ROUND_UP_2(h)))
	#define GST_VIDEO_I420_V_OFFSET(w,h) (GST_VIDEO_I420_U_OFFSET(w,h)+(GST_VIDEO_I420_U_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

	#define GST_VIDEO_I420_SIZE(w,h) (GST_VIDEO_I420_V_OFFSET(w,h)+(GST_VIDEO_I420_V_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

	static gboolean
	gst_navigationtest_get_unit_size (GstBaseTransform * btrans, GstCaps * caps,
	guint * size)
	{
	GstNavigationtest *navtest;
	GstStructure *structure;
	gboolean ret = FALSE;
	gint width, height;

	navtest = GST_NAVIGATIONTEST (btrans);

	structure = gst_caps_get_structure (caps, 0);

	if (gst_structure_get_int (structure, "width", &width) &&
	gst_structure_get_int (structure, "height", &height)) {
	*size = GST_VIDEO_I420_SIZE (width, height);
	ret = TRUE;
	GST_DEBUG_OBJECT (navtest, "our frame size is %d bytes (%dx%d)", *size,
	width, height);
	}

	return ret;
	}

	static gboolean
	gst_navigationtest_set_caps (GstBaseTransform * btrans, GstCaps * incaps,
	GstCaps * outcaps)
	{
	GstNavigationtest *navtest = GST_NAVIGATIONTEST (btrans);
	gboolean ret = FALSE;
	GstStructure *structure;

	structure = gst_caps_get_structure (incaps, 0);

	if (gst_structure_get_int (structure, "width", &navtest->width) &&
	gst_structure_get_int (structure, "height", &navtest->height)) {
	const GValue *framerate;

	framerate = gst_structure_get_value (structure, "framerate");
	if (framerate && GST_VALUE_HOLDS_FRACTION (framerate)) {
	g_value_copy (framerate, &navtest->framerate);
	ret = TRUE;
	}
	}

	return ret;
	}

	static void
	draw_box_planar411 (guint8 * dest, int width, int height, int x, int y,
	guint8 colory, guint8 coloru, guint8 colorv)
	{
	int x1, x2, y1, y2;
	guint8 *d = dest;

	if (x < 0 \|\| y < 0 \|\| x >= width \|\| y >= height)
	return;

	x1 = MAX (x - 5, 0);
	x2 = MIN (x + 5, width);
	y1 = MAX (y - 5, 0);
	y2 = MIN (y + 5, height);

	for (y = y1; y < y2; y++) {
	for (x = x1; x < x2; x++) {
	((guint8 ) d)[y GST_VIDEO_I420_Y_ROWSTRIDE (width) + x] = colory;
	}
	}

	d = dest + GST_VIDEO_I420_U_OFFSET (width, height);
	x1 /= 2;
	x2 /= 2;
	y1 /= 2;
	y2 /= 2;
	for (y = y1; y < y2; y++) {
	for (x = x1; x < x2; x++) {
	((guint8 ) d)[y GST_VIDEO_I420_U_ROWSTRIDE (width) + x] = coloru;
	}
	}

	d = dest + GST_VIDEO_I420_V_OFFSET (width, height);
	for (y = y1; y < y2; y++) {
	for (x = x1; x < x2; x++) {
	((guint8 ) d)[y GST_VIDEO_I420_V_ROWSTRIDE (width) + x] = colorv;
	}
	}
	}

	static GstFlowReturn
	gst_navigationtest_transform (GstBaseTransform * trans, GstBuffer * in,
	GstBuffer * out)
	{
	GstNavigationtest *navtest = GST_NAVIGATIONTEST (trans);
	GSList *walk;
	GstFlowReturn ret = GST_FLOW_OK;

	/* do something interesting here. This simply copies the source
	* to the destination. */
	gst_buffer_copy_metadata (out, in, GST_BUFFER_COPY_TIMESTAMPS);

	memcpy (GST_BUFFER_DATA (out), GST_BUFFER_DATA (in),
	MIN (GST_BUFFER_SIZE (in), GST_BUFFER_SIZE (out)));

	walk = navtest->clicks;
	while (walk) {
	ButtonClick *click = walk->data;

	walk = g_slist_next (walk);
	draw_box_planar411 (GST_BUFFER_DATA (out), navtest->width, navtest->height,
	rint (click->x), rint (click->y), click->cy, click->cu, click->cv);
	if (--click->images_left < 1) {
	navtest->clicks = g_slist_remove (navtest->clicks, click);
	g_free (click);
	}
	}
	draw_box_planar411 (GST_BUFFER_DATA (out), navtest->width, navtest->height,
	rint (navtest->x), rint (navtest->y), 0, 128, 128);

	return ret;
	}

	static GstStateChangeReturn
	gst_navigationtest_change_state (GstElement * element,
	GstStateChange transition)
	{
	GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
	GstNavigationtest *navtest = GST_NAVIGATIONTEST (element);

	if (GST_ELEMENT_CLASS (parent_class)->change_state)
	ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);

	/* downwards state changes */
	switch (transition) {
	case GST_STATE_CHANGE_PAUSED_TO_READY:
	{
	g_slist_foreach (navtest->clicks, (GFunc) g_free, NULL);
	g_slist_free (navtest->clicks);
	navtest->clicks = NULL;
	break;
	}
	default:
	break;
	}

	return ret;
	}

	static void
	gst_navigationtest_base_init (gpointer g_class)
	{
	GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

	gst_element_class_set_details (element_class, &navigationtest_details);

	gst_element_class_add_pad_template (element_class,
	gst_static_pad_template_get (&gst_navigationtest_sink_template));
	gst_element_class_add_pad_template (element_class,
	gst_static_pad_template_get (&gst_navigationtest_src_template));
	}

	static void
	gst_navigationtest_class_init (gpointer klass, gpointer class_data)
	{
	GstElementClass *element_class;
	GstBaseTransformClass *trans_class;

	element_class = (GstElementClass *) klass;
	trans_class = (GstBaseTransformClass *) klass;

	parent_class = g_type_class_peek_parent (klass);

	element_class->change_state =
	GST_DEBUG_FUNCPTR (gst_navigationtest_change_state);

	trans_class->set_caps = GST_DEBUG_FUNCPTR (gst_navigationtest_set_caps);
	trans_class->get_unit_size =
	GST_DEBUG_FUNCPTR (gst_navigationtest_get_unit_size);
	trans_class->transform = GST_DEBUG_FUNCPTR (gst_navigationtest_transform);
	}

	static void
	gst_navigationtest_init (GTypeInstance * instance, gpointer g_class)
	{
	GstNavigationtest *navtest = GST_NAVIGATIONTEST (instance);
	GstBaseTransform *btrans = GST_BASE_TRANSFORM (instance);

	gst_pad_set_event_function (btrans->srcpad,
	GST_DEBUG_FUNCPTR (gst_navigationtest_handle_src_event));

	navtest->x = -1;
	navtest->y = -1;
	g_value_init (&navtest->framerate, GST_TYPE_FRACTION);
	}

	GType
	gst_navigationtest_get_type (void)
	{
	static GType navigationtest_type = 0;

	if (!navigationtest_type) {
	static const GTypeInfo navigationtest_info = {
	sizeof (GstNavigationtestClass),
	gst_navigationtest_base_init,
	NULL,
	gst_navigationtest_class_init,
	NULL,
	NULL,
	sizeof (GstNavigationtest),
	0,
	gst_navigationtest_init,
	};

	navigationtest_type = g_type_register_static (GST_TYPE_VIDEO_FILTER,
	"GstNavigationtest", &navigationtest_info, 0);
	}
	return navigationtest_type;
	}

	static gboolean
	plugin_init (GstPlugin * plugin)
	{
	GST_DEBUG_CATEGORY_INIT (navigationtest_debug, "navigationtest", 0,
	"navigationtest");

	return gst_element_register (plugin, "navigationtest", GST_RANK_NONE,
	GST_TYPE_NAVIGATIONTEST);
	}

	GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
	GST_VERSION_MINOR,
	"navigationtest",
	"Template for a video filter",
	plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)