gstreamer/sys/glsink/gstglsink.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * 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.
 */

/*
<ds-work> your element belongs to a scheduler, which calls some functions from the same thread
<ds-work> all the other functions could be called from any random thread
<gernot> ds-work: which are the "some" function in that case ? 
<gernot> It is quite costly to do glXGetCurrentContext for every function call.
<ds-work> _chain, -get, _loop
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <GL/glx.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <sys/time.h>

/*#define GST_DEBUG_FORCE_DISABLE*/

#include "gstglsink.h"

/* elementfactory information */
static GstElementDetails gst_glsink_details = {
  "OpenGL Sink/GLX",
  "Sink/GLVideo",
  "An OpenGL based video sink - uses OpenGL and GLX to draw video, utilizing different acceleration options",
  "Gernot Ziegler <gz@lysator.liu.se>"
};

/* default template - initiated with class struct to allow gst-register to work
   with X running */
GST_PAD_TEMPLATE_FACTORY (gst_glsink_sink_template_factory,
  "sink",
  GST_PAD_SINK,
  GST_PAD_ALWAYS,
  GST_CAPS_NEW ( "glsink_rgbsink", "video/x-raw-rgb",
    "framerate", GST_PROPS_FLOAT_RANGE(0, G_MAXFLOAT),
    "width", GST_PROPS_INT_RANGE(0, G_MAXINT),
    "height", GST_PROPS_INT_RANGE(0, G_MAXINT)),
  GST_CAPS_NEW ( "glsink_yuvsink", "video/x-raw-yuv",
    "framerate", GST_PROPS_FLOAT_RANGE(0, G_MAXFLOAT),
    "width", GST_PROPS_INT_RANGE(0, G_MAXINT),
    "height", GST_PROPS_INT_RANGE(0, G_MAXINT))
)

/* glsink signals and args */
enum {
  LAST_SIGNAL
};


enum {
  ARG_0,
  ARG_WIDTH,
  ARG_HEIGHT,
  ARG_FRAMES_DISPLAYED,
  ARG_FRAME_TIME,
  ARG_HOOK,
  ARG_MUTE,
  ARG_REPAINT,
  ARG_DEMO,
  ARG_DUMP
};

/* GLsink class */
#define GST_TYPE_GLSINK		(gst_glsink_get_type())
#define GST_GLSINK(obj)		(G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_GLSINK,GstGLSink))
#define GST_GLSINK_CLASS(klass)	(G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_GLSINK,GstGLSink))
#define GST_IS_GLSINK(obj)		(G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_GLSINK))
#define GST_IS_GLSINK_CLASS(obj)	(G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_GLSINK))

typedef struct _GstGLSink GstGLSink;
typedef struct _GstGLSinkClass GstGLSinkClass;

struct _GstGLSink {
  GstElement element;

  GstPad *sinkpad;

  gint frames_displayed;
  guint64 frame_time;
  gint width, height;
  gboolean muted;
  gint demo; // some kind of fun demo mode to let GL show its 3D capabilities
  gboolean dumpvideo; // dump the video down to .ppm:s 
  GstBuffer *last_image; /* not thread safe ? */
  
  GstClock *clock;

  GMutex *cache_lock;
  GList *cache;
  
  /* plugins */
  GstImagePlugin* plugin;
  GstImageConnection *conn;
  
  /* allow anybody to hook in here */
  GstImageInfo *hook;
};

struct _GstGLSinkClass {
  GstElementClass parent_class;

  /* plugins */
  GList *plugins;
};


static GType 			gst_glsink_get_type		(void);
static void		gst_glsink_base_init	(gpointer g_class);
static void			gst_glsink_class_init	(GstGLSinkClass *klass);
static void			gst_glsink_init		(GstGLSink *sink);
/* static void 			gst_glsink_dispose 		(GObject *object); */

static void                     gst_glsink_chain                (GstPad *pad, GstData *_data);
static void			gst_glsink_set_clock		(GstElement *element, GstClock *clock);
static GstElementStateReturn	gst_glsink_change_state 	(GstElement *element);
static GstPadLinkReturn	gst_glsink_sinkconnect	(GstPad *pad, GstCaps *caps);
static GstCaps *		gst_glsink_getcaps		(GstPad *pad, GstCaps *caps);

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

static void			gst_glsink_release_conn	(GstGLSink *sink);
static void			gst_glsink_append_cache	(GstGLSink *sink, GstImageData *image);
static gboolean			gst_glsink_set_caps		(GstGLSink *sink, GstCaps *caps);

/* prototypes from plugins */
extern GstImagePlugin* 		get_gl_rgbimage_plugin		(void);
extern GstImagePlugin* 		get_gl_nvimage_plugin		(void);
/* default output */
extern void			gst_glxwindow_new 		(GstGLSink *sink);
extern void			gst_glxwindow_hook_context 		(GstImageInfo *info);
extern void			gst_glxwindow_unhook_context 		(GstImageInfo *info);


static GstPadTemplate *sink_template;

static GstElementClass *parent_class = NULL;
/* static guint gst_glsink_signals[LAST_SIGNAL] = { 0 }; */

static GType
gst_glsink_get_type (void)
{
  static GType videosink_type = 0;

  if (!videosink_type) {
    static const GTypeInfo videosink_info = {
      sizeof(GstGLSinkClass),
      gst_glsink_base_init,
      NULL,
      (GClassInitFunc) gst_glsink_class_init,
      NULL,
      NULL,
      sizeof(GstGLSink),
      0,
      (GInstanceInitFunc) gst_glsink_init,
    };
    videosink_type = g_type_register_static(GST_TYPE_ELEMENT, "GstGLSink", &videosink_info, 0);
  }
  return videosink_type;
}

static void
gst_glsink_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
  
  gst_element_class_set_details (element_class, &gst_glsink_details);

  gst_element_class_add_pad_template (
    element_class, 
    GST_PAD_TEMPLATE_GET (gst_glsink_sink_template_factory));
}

static void
gst_glsink_class_init (GstGLSinkClass *klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass*) klass;

  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);

  g_object_class_install_property (gobject_class, ARG_WIDTH,
    g_param_spec_int ("width", "Width", "The video width",
                      G_MININT, G_MAXINT, 0, G_PARAM_READABLE)); /* CHECKME */
  g_object_class_install_property (gobject_class, ARG_HEIGHT,
    g_param_spec_int ("height", "Height", "The video height",
                      G_MININT, G_MAXINT, 0, G_PARAM_READABLE)); /* CHECKME */
  g_object_class_install_property (gobject_class, ARG_FRAMES_DISPLAYED,
    g_param_spec_int ("frames_displayed", "Frames Displayed", "The number of frames displayed so far",
                      G_MININT,G_MAXINT, 0, G_PARAM_READWRITE)); /* CHECKME */
  g_object_class_install_property (gobject_class, ARG_FRAME_TIME,
    g_param_spec_int ("frame_time", "Frame time", "The interval between frames",
                      G_MININT, G_MAXINT, 0, G_PARAM_READWRITE)); /* CHECKME */
  g_object_class_install_property (gobject_class, ARG_HOOK,
    g_param_spec_pointer ("hook", "Hook", "The object receiving the output", G_PARAM_WRITABLE));
  g_object_class_install_property (gobject_class, ARG_MUTE,
    g_param_spec_boolean ("mute", "Mute", "mute the output ?", FALSE, G_PARAM_READWRITE));
  g_object_class_install_property (gobject_class, ARG_REPAINT,
    g_param_spec_boolean ("repaint", "Repaint", "repaint the current frame", FALSE, G_PARAM_WRITABLE));
  g_object_class_install_property (gobject_class, ARG_DEMO,
    g_param_spec_int ("demo", "Demo", "demo mode (shows 3D capabilities)",0, 1, 0, G_PARAM_READWRITE)); 
  g_object_class_install_property (gobject_class, ARG_DUMP,
    g_param_spec_boolean ("dump", "Dump", "stores sequence of frames in .ppm files", FALSE, G_PARAM_READWRITE));

  gobject_class->set_property = gst_glsink_set_property;
  gobject_class->get_property = gst_glsink_get_property;

  /*gobject_class->dispose = gst_glsink_dispose; */
  
  gstelement_class->change_state = gst_glsink_change_state;
  gstelement_class->set_clock = gst_glsink_set_clock;
  
  /* plugins */
  klass->plugins = NULL;
  klass->plugins = g_list_append (klass->plugins, get_gl_rgbimage_plugin ());
  klass->plugins = g_list_append (klass->plugins, get_gl_nvimage_plugin ());
}


/*
  GLSink has its own Buffer management - this allows special plugins to create special memory areas for
  buffer upload 
*/
static void
gst_glsink_init (GstGLSink *sink)
{
  sink->sinkpad = gst_pad_new_from_template (sink_template, "sink");
  gst_element_add_pad (GST_ELEMENT (sink), sink->sinkpad);
  gst_pad_set_chain_function (sink->sinkpad, gst_glsink_chain);
  gst_pad_set_link_function (sink->sinkpad, gst_glsink_sinkconnect);
  gst_pad_set_getcaps_function (sink->sinkpad, gst_glsink_getcaps);
  gst_pad_set_bufferpool_function (sink->sinkpad, gst_glsink_get_bufferpool);

  sink->last_image = NULL;
  sink->width = 0;
  sink->height = 0;
  sink->muted = FALSE;
  sink->clock = NULL;  
  GST_FLAG_SET(sink, GST_ELEMENT_THREAD_SUGGESTED);
  GST_FLAG_SET (sink, GST_ELEMENT_EVENT_AWARE);
    
  /* create bufferpool and image cache */
  GST_DEBUG ("glsink: creating bufferpool");
  sink->cache_lock = g_mutex_new();
  sink->cache = NULL; 
  
  /* plugins */
  sink->plugin = NULL;
  sink->conn = NULL;
  
  /* do initialization of default hook here */
  gst_glxwindow_new (sink); 
  //printf("GLSink_init: Current context %p\n", glXGetCurrentContext());
  gst_glxwindow_unhook_context(sink->hook);
}

/** frees the temporary connection that tests the window system capabilities */
static void
gst_glsink_release_conn (GstGLSink *sink)
{
  if (sink->conn == NULL) return;
  
  /* free last image if any */
  if (sink->last_image != NULL)
  {
    gst_buffer_unref (sink->last_image);
    sink->last_image = NULL;
  }
  /* free cache */
  g_mutex_lock (sink->cache_lock);
  while (sink->cache)
  {
    sink->plugin->free_image ((GstImageData *) sink->cache->data);
    sink->cache = g_list_delete_link (sink->cache, sink->cache);
  }
  g_mutex_unlock (sink->cache_lock);
  
  /* release connection */
  sink->conn->free_conn (sink->conn);
  sink->conn = NULL;
}

static void 		
gst_glsink_append_cache (GstGLSink *sink, GstImageData *image)
{
  g_mutex_lock (sink->cache_lock);
  sink->cache = g_list_prepend (sink->cache, image);
  g_mutex_unlock (sink->cache_lock);
}

#if 0
/* 
   Create a new buffer to hand up the chain.
   This allows the plugins to make its own decoding buffers
 */
static GstBuffer*
gst_glsink_buffer_new (GstBufferPool *pool, gint64 location, 
		          guint size, gpointer user_data)
{
  GstGLSink *sink;
  GstBuffer *buffer;
  GstImageData *image;
  
  sink = GST_GLSINK (user_data);
  
  /* If cache is non-empty, get buffer from there */
  if (sink->cache != NULL) {
    g_mutex_lock (sink->cache_lock);
    image = (GstImageData *) sink->cache->data;
    sink->cache = g_list_delete_link (sink->cache, sink->cache);
    g_mutex_unlock (sink->cache_lock);
  } else {
    /* otherwise, get one from the plugin */
    image = sink->plugin->get_image (sink->hook, sink->conn);
  }
  
  buffer = gst_buffer_new ();
  GST_BUFFER_DATA (buffer) = image->data;
  GST_BUFFER_SIZE (buffer) = image->size;
  GST_BUFFER_POOL_PRIVATE (buffer) = image;
  
  return buffer;
}

/*
  Free a buffer that the chain doesn't need anymore. 
*/
static void
gst_glsink_buffer_free (GstBufferPool *pool, GstBuffer *buffer, gpointer user_data)
{
  GstGLSink *sink = GST_GLSINK (gst_buffer_pool_get_user_data (GST_BUFFER_BUFFERPOOL (buffer)));

  gst_glsink_append_cache (sink, (GstImageData *) GST_BUFFER_POOL_PRIVATE (buffer));

  /* set to NULL so the data is not freed */
  GST_BUFFER_DATA (buffer) = NULL;

  gst_buffer_default_free (buffer);
}
#endif

/* 
   Set the caps that the application desires. 
   Go through the plugin list, finding the plugin that first fits the given parameters 
*/
static gboolean
gst_glsink_set_caps (GstGLSink *sink, GstCaps *caps)
{
  g_warning("in glsink set caps!\n");
  printf("Getting GLstring, context is %p\n",  glXGetCurrentContext());
    
  GList *list = ((GstGLSinkClass *) G_OBJECT_GET_CLASS (sink))->plugins;
  GstImageConnection *conn = NULL;
  while (list)    
  {
  printf("AGetting GLstring, context is %p\n",  glXGetCurrentContext());
    GstImagePlugin *plugin = (GstImagePlugin *) list->data;
    if ((conn = plugin->set_caps (sink->hook, caps)) != NULL)
    {
      //gst_glsink_release_conn (sink);
  printf("BGetting GLstring, context is %p\n",  glXGetCurrentContext());
      sink->conn = conn;
  printf("CGetting GLstring, context is %p\n",  glXGetCurrentContext());
      sink->plugin = plugin;
      sink->conn->open_conn (sink->conn, sink->hook);
      return TRUE;
    }
    list = g_list_next (list);
  }
  return FALSE;
}

/**
Link the input video sink internally.
*/
static GstPadLinkReturn
gst_glsink_sinkconnect (GstPad *pad, GstCaps *caps)
{
  g_warning("in glsink sinkconnect!\n");
  GstGLSink *sink;
  guint32 fourcc, print_format, result;

  sink = GST_GLSINK (gst_pad_get_parent (pad));

  /* we are not going to act on variable caps */
  if (!GST_CAPS_IS_FIXED (caps))
    return GST_PAD_LINK_DELAYED;
  
  gst_glxwindow_hook_context(sink->hook);
  /* try to set the caps on the output */
  result = gst_glsink_set_caps (sink, caps);
  gst_glxwindow_unhook_context(sink->hook);

  if (result == FALSE)
    {
      return GST_PAD_LINK_REFUSED;
    }
  
  /* remember width & height */
  gst_caps_get_int (caps, "width", &sink->width);
  gst_caps_get_int (caps, "height", &sink->height);

  gst_caps_get_fourcc_int (caps, "format", &fourcc);
  print_format = GULONG_FROM_LE (fourcc);
  GST_DEBUG ("glsink: setting %08x (%4.4s) %dx%d\n", 
		  fourcc, (gchar*)&print_format, sink->width, sink->height);

  /* emit signal */
  g_object_freeze_notify (G_OBJECT (sink));
  g_object_notify (G_OBJECT (sink), "width");
  g_object_notify (G_OBJECT (sink), "height");
  g_object_thaw_notify (G_OBJECT (sink));

  return GST_PAD_LINK_OK;
}
static GstCaps *
gst_glsink_getcaps (GstPad *pad, GstCaps *caps)
{
  g_warning("in glsink get caps!\n");
  /* what is the "caps" parameter good for? */
  GstGLSink *sink = GST_GLSINK (gst_pad_get_parent (pad));
  GstCaps *ret = NULL;
  GList *list = ((GstGLSinkClass *) G_OBJECT_GET_CLASS (sink))->plugins;
  
  gst_glxwindow_hook_context(sink->hook);
  while (list)    
  {
    ret = gst_caps_append (ret, ((GstImagePlugin *) list->data)->get_caps (sink->hook));
    list = g_list_next (list);
  }

  gst_glxwindow_unhook_context(sink->hook);
  return ret;
}

static void
gst_glsink_set_clock (GstElement *element, GstClock *clock)
{
  GstGLSink *sink = GST_GLSINK (element);
  
  sink->clock = clock;
}
static void
gst_glsink_chain (GstPad *pad, GstData *_data)
{
  //g_warning("in glsink_chain!\n");
  GstBuffer *buf = GST_BUFFER (_data);
  GstGLSink *sink;

  GstBuffer *buffer;

  g_return_if_fail (pad != NULL);
  g_return_if_fail (GST_IS_PAD (pad));
  g_return_if_fail (buf != NULL);

  sink = GST_GLSINK (gst_pad_get_parent (pad));

  if (GST_IS_EVENT (buf)) {
    GstEvent *event = GST_EVENT (buf);

    switch (GST_EVENT_TYPE (event)) {
      default:
        gst_pad_event_default (pad, event);
    }
    return;
  }
  GST_DEBUG ("glsink: clock wait: %llu %u", 
		  GST_BUFFER_TIMESTAMP (buf), GST_BUFFER_SIZE (buf));

#if 0
  GstClockTime time = GST_BUFFER_TIMESTAMP (buf);
  static int frame_drops = 0;

  if (sink->clock && time != -1) {
    if (time < gst_clock_get_time(sink->clock))
      {
	g_warning("Frame drop (%d consecutive) !!", frame_drops);
	/* we are going to drop late buffers */
	gst_buffer_unref (buf);
	frame_drops++;
	return;
      }
    frame_drops = 0; // we made it - reset time

    GstClockReturn ret;
    GstClockID id = gst_clock_new_single_shot_id (sink->clock, GST_BUFFER_TIMESTAMP (buf));

    ret = gst_element_clock_wait (GST_ELEMENT (sink), id, NULL);
    gst_clock_id_free (id);

    /* we are going to drop early buffers */
    if (ret == GST_CLOCK_EARLY) {
      gst_buffer_unref (buf);
      return;
    }
  }
#endif

  /* call the notify _before_ displaying so the handlers can react */
  sink->frames_displayed++;
  g_object_notify (G_OBJECT (sink), "frames_displayed");

  if (!sink->muted)
  {
    if (glXGetCurrentContext() == NULL)
      {
	printf("Rehooking window !\n");
	gst_glxwindow_hook_context(sink->hook);

#if 1
	GST_DEBUG("Initializing OpenGL parameters\n");
	/* initialize OpenGL drawing */
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_TEXTURE_2D);
	glClearDepth(1.0f);
	glClearColor(0, 0, 0, 0);
	
	glEnable(GL_AUTO_NORMAL); // let OpenGL generate the Normals
	
	glDisable(GL_BLEND);
	glDisable(GL_CULL_FACE);
	glPolygonMode(GL_FRONT, GL_FILL);
	glPolygonMode(GL_BACK, GL_FILL);
	
	glShadeModel(GL_SMOOTH);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
	
	GstGLImageInfo *window = (GstGLImageInfo *)sink->hook;
	int w=window->width, h = window->height;

	glViewport(0, 0, (GLint) w, (GLint) h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	
	GLfloat aspect = (GLfloat) w / (GLfloat) h;
	glFrustum(-aspect, aspect, -1.0, 1.0, 5.0, 500.0);

#endif
	gst_glxwindow_unhook_context(sink->hook);
	gst_glxwindow_hook_context(sink->hook);
	glMatrixMode(GL_MODELVIEW);
#if 0 
	sink->hook->free_info(sink->hook);
	printf("Reallocating window brutally !\n");
	gst_glxwindow_new(sink);
#endif
      }
    
    /* free last_image, if any */
    if (sink->last_image != NULL)
      gst_buffer_unref (sink->last_image);
    if (sink->bufferpool && GST_BUFFER_BUFFERPOOL (buf) == sink->bufferpool) {
      
      // awful hack ! But I currently have no other solution without changing the API
      sink->hook->demo = sink->demo;
      sink->hook->dumpvideo = sink->dumpvideo;

      sink->plugin->put_image (sink->hook, (GstImageData *) GST_BUFFER_POOL_PRIVATE (buf));
      sink->last_image = buf;
    } else {
      buffer = gst_buffer_new_from_pool (gst_glsink_get_bufferpool (sink->sinkpad), 
		                         0, GST_BUFFER_SIZE (buf));
      memcpy (GST_BUFFER_DATA (buffer), GST_BUFFER_DATA (buf), 
	      GST_BUFFER_SIZE (buf) > GST_BUFFER_SIZE (buffer) ? 
	        GST_BUFFER_SIZE (buffer) : GST_BUFFER_SIZE (buf));

      sink->plugin->put_image (sink->hook, (GstImageData *) GST_BUFFER_POOL_PRIVATE (buffer));

      sink->last_image = buffer;
      gst_buffer_unref (buf);
    }

    //gst_glxwindow_unhook_context(sink->hook);
  }
  
}


static void
gst_glsink_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
  //g_warning("in set_property!\n");
  GstGLSink *sink;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_GLSINK (object));

  sink = GST_GLSINK (object);

  switch (prop_id) {
    case ARG_FRAMES_DISPLAYED:
      sink->frames_displayed = g_value_get_int (value);
      g_object_notify (object, "frames_displayed");
      break;
    case ARG_FRAME_TIME:
      sink->frame_time = g_value_get_int (value);
      break;
    case ARG_HOOK:
      if (sink->hook)
      {
	sink->hook->free_info (sink->hook);
      }
      sink->hook = g_value_get_pointer (value);
      break;
    case ARG_MUTE:
      sink->muted = g_value_get_boolean (value);
      g_object_notify (object, "mute");
      break;
    case ARG_DEMO:
      sink->demo = g_value_get_int (value);
      g_object_notify (object, "demo");
      break;
    case ARG_DUMP:
      sink->dumpvideo = g_value_get_boolean (value);
      g_object_notify (object, "dump");
      break;
    case ARG_REPAINT:
      if (sink->last_image != NULL) {
	sink->plugin->put_image (sink->hook, (GstImageData *) GST_BUFFER_POOL_PRIVATE (sink->last_image));
      }
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_glsink_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
  //g_warning("in get_property!\n");
  GstGLSink *sink;

  /* it's not null if we got it, but it might not be ours */
  sink = GST_GLSINK(object);

  switch (prop_id) {
    case ARG_WIDTH:
      g_value_set_int (value, sink->width);
      break;
    case ARG_HEIGHT:
      g_value_set_int (value, sink->height);
      break;
    case ARG_FRAMES_DISPLAYED:
      g_value_set_int (value, sink->frames_displayed);
      break;
    case ARG_FRAME_TIME:
      g_value_set_int (value, sink->frame_time/1000000);
      break;
    case ARG_MUTE:
      g_value_set_boolean (value, sink->muted);
      break;
    case ARG_DEMO:
      g_value_set_int (value, sink->demo);
      break;
    case ARG_DUMP:
      g_value_set_boolean (value, sink->dumpvideo);
      break;
    default: 
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


static GstElementStateReturn
gst_glsink_change_state (GstElement *element)
{
  //g_warning("in change_state!\n");
  GstGLSink *sink;

  sink = GST_GLSINK (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_NULL_TO_READY:
      break;
    case GST_STATE_READY_TO_PAUSED:
      {
	//g_warning("Going GST_STATE_READY_TO_PAUSED: %p", sink->conn);
      }
      break;
    case GST_STATE_PAUSED_TO_PLAYING:
      {
	//g_warning("Going GST_STATE_PAUSED_TO_PLAYING: %p", sink->conn);
      }
      break;
    case GST_STATE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      if (sink->conn)
        sink->conn->close_conn (sink->conn, sink->hook);
      if (sink->last_image) {
	gst_buffer_unref (sink->last_image);
        sink->last_image = NULL;
      }
      break;
    case GST_STATE_READY_TO_NULL:
      gst_glsink_release_conn (sink);
      break;
  }

  parent_class->change_state (element);

  return GST_STATE_SUCCESS;
}

static gboolean
plugin_init (GstPlugin *plugin)
{
  /* Loading the library containing GstVideoSink, our parent object */
  if (!gst_library_load ("gstvideo"))
    return FALSE;

  /* this is needed later on in the _real_ init (during a gst-launch) */
  sink_template = gst_pad_template_new (
		  "sink",
                  GST_PAD_SINK,
  		  GST_PAD_ALWAYS,
		  NULL);

  if (!gst_element_register (plugin, "glsink", GST_RANK_NONE, GST_TYPE_GLSINK))
    return FALSE;

  return TRUE;
}

GST_PLUGIN_DEFINE (
  GST_VERSION_MAJOR,
  GST_VERSION_MINOR,
  "glsink",
  "An OpenGL based video sink - uses OpenGL and GLX to draw video, utilizing different acceleration options",
  plugin_init,
  VERSION,
  GST_LICENSE,
  GST_PACKAGE,
  GST_ORIGIN
);