gstreamer/sys/ximage/ximagesink.c

/* GStreamer
 * Copyright (C) <2005> Julien Moutte <julien@moutte.net>
 *
 * 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-ximagesink
 * @title: ximagesink
 *
 * XImageSink renders video frames to a drawable (XWindow) on a local or remote
 * display. This element can receive a Window ID from the application through
 * the #GstVideoOverlay interface and will then render video frames in this
 * drawable. If no Window ID was provided by the application, the element will
 * create its own internal window and render into it.
 *
 * ## Scaling
 *
 * As standard XImage rendering to a drawable is not scaled, XImageSink will use
 * reverse caps negotiation to try to get scaled video frames for the drawable.
 * This is accomplished by asking the peer pad if it accepts some different caps
 * which in most cases implies that there is a scaling element in the pipeline,
 * or that an element generating the video frames can generate them with a
 * different geometry. This mechanism is handled during buffer allocations, for
 * each allocation request the video sink will check the drawable geometry, look
 * at the #GstXImageSink:force-aspect-ratio property, calculate the geometry of
 * desired video frames and then check that the peer pad accept those new caps.
 * If it does it will then allocate a buffer in video memory with this new
 * geometry and return it with the new caps.
 *
 * ## Events
 *
 * XImageSink creates a thread to handle events coming from the drawable. There
 * are several kind of events that can be grouped in 2 big categories: input
 * events and window state related events. Input events will be translated to
 * navigation events and pushed upstream for other elements to react on them.
 * This includes events such as pointer moves, key press/release, clicks etc...
 * Other events are used to handle the drawable appearance even when the data
 * is not flowing (GST_STATE_PAUSED). That means that even when the element is
 * paused, it will receive expose events from the drawable and draw the latest
 * frame with correct borders/aspect-ratio.
 *
 * ## Pixel aspect ratio
 *
 * When changing state to GST_STATE_READY, XImageSink will open a connection to
 * the display specified in the #GstXImageSink:display property or the default
 * display if nothing specified. Once this connection is open it will inspect
 * the display configuration including the physical display geometry and
 * then calculate the pixel aspect ratio. When caps negotiation will occur, the
 * video sink will set the calculated pixel aspect ratio on the caps to make
 * sure that incoming video frames will have the correct pixel aspect ratio for
 * this display. Sometimes the calculated pixel aspect ratio can be wrong, it is
 * then possible to enforce a specific pixel aspect ratio using the
 * #GstXImageSink:pixel-aspect-ratio property.
 *
 * ## Examples
 * |[
 * gst-launch-1.0 -v videotestsrc ! queue ! ximagesink
 * ]|
 *  A pipeline to test reverse negotiation. When the test video signal appears
 * you can resize the window and see that scaled buffers of the desired size are
 * going to arrive with a short delay. This illustrates how buffers of desired
 * size are allocated along the way. If you take away the queue, scaling will
 * happen almost immediately.
 * |[
 * gst-launch-1.0 -v videotestsrc ! navigationtest ! videoconvert ! ximagesink
 * ]|
 *  A pipeline to test navigation events.
 * While moving the mouse pointer over the test signal you will see a black box
 * following the mouse pointer. If you press the mouse button somewhere on the
 * video and release it somewhere else a green box will appear where you pressed
 * the button and a red one where you released it. (The navigationtest element
 * is part of gst-plugins-good.)
 * |[
 * gst-launch-1.0 -v videotestsrc ! video/x-raw, pixel-aspect-ratio=(fraction)4/3 ! videoscale ! ximagesink
 * ]|
 *  This is faking a 4/3 pixel aspect ratio caps on video frames produced by
 * videotestsrc, in most cases the pixel aspect ratio of the display will be
 * 1/1. This means that videoscale will have to do the scaling to convert
 * incoming frames to a size that will match the display pixel aspect ratio
 * (from 320x240 to 320x180 in this case). Note that you might have to escape
 * some characters for your shell like '\(fraction\)'.
 *
 */

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

/* Our interfaces */
#include <gst/video/navigation.h>
#include <gst/video/videooverlay.h>

#include <gst/video/gstvideometa.h>

/* Object header */
#include "ximagesink.h"

/* Debugging category */
#include <gst/gstinfo.h>

/* for XkbKeycodeToKeysym */
#include <X11/XKBlib.h>

GST_DEBUG_CATEGORY_EXTERN (gst_debug_x_image_sink);
GST_DEBUG_CATEGORY_EXTERN (CAT_PERFORMANCE);
#define GST_CAT_DEFAULT gst_debug_x_image_sink

typedef struct
{
  unsigned long flags;
  unsigned long functions;
  unsigned long decorations;
  long input_mode;
  unsigned long status;
}
MotifWmHints, MwmHints;

#define MWM_HINTS_DECORATIONS   (1L << 1)

static void gst_x_image_sink_reset (GstXImageSink * ximagesink);
static void gst_x_image_sink_xwindow_update_geometry (GstXImageSink *
    ximagesink);
static void gst_x_image_sink_expose (GstVideoOverlay * overlay);

static GstStaticPadTemplate gst_x_image_sink_sink_template_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw, "
        "framerate = (fraction) [ 0, MAX ], "
        "width = (int) [ 1, MAX ], " "height = (int) [ 1, MAX ]")
    );

enum
{
  PROP_0,
  PROP_DISPLAY,
  PROP_SYNCHRONOUS,
  PROP_PIXEL_ASPECT_RATIO,
  PROP_FORCE_ASPECT_RATIO,
  PROP_HANDLE_EVENTS,
  PROP_HANDLE_EXPOSE,
  PROP_WINDOW_WIDTH,
  PROP_WINDOW_HEIGHT
};

/* ============================================================= */
/*                                                               */
/*                       Public Methods                          */
/*                                                               */
/* ============================================================= */

/* =========================================== */
/*                                             */
/*          Object typing & Creation           */
/*                                             */
/* =========================================== */
static void gst_x_image_sink_navigation_init (GstNavigationInterface * iface);
static void gst_x_image_sink_video_overlay_init (GstVideoOverlayInterface *
    iface);
#define gst_x_image_sink_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstXImageSink, gst_x_image_sink, GST_TYPE_VIDEO_SINK,
    G_IMPLEMENT_INTERFACE (GST_TYPE_NAVIGATION,
        gst_x_image_sink_navigation_init);
    G_IMPLEMENT_INTERFACE (GST_TYPE_VIDEO_OVERLAY,
        gst_x_image_sink_video_overlay_init));

/* ============================================================= */
/*                                                               */
/*                       Private Methods                         */
/*                                                               */
/* ============================================================= */

/* X11 stuff */

/* We are called with the x_lock taken */
static void
gst_x_image_sink_xwindow_draw_borders (GstXImageSink * ximagesink,
    GstXWindow * xwindow, GstVideoRectangle rect)
{
  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));
  g_return_if_fail (xwindow != NULL);

  XSetForeground (ximagesink->xcontext->disp, xwindow->gc,
      ximagesink->xcontext->black);

  /* Left border */
  if (rect.x > 0) {
    XFillRectangle (ximagesink->xcontext->disp, xwindow->win, xwindow->gc,
        0, 0, rect.x, xwindow->height);
  }

  /* Right border */
  if ((rect.x + rect.w) < xwindow->width) {
    XFillRectangle (ximagesink->xcontext->disp, xwindow->win, xwindow->gc,
        rect.x + rect.w, 0, xwindow->width, xwindow->height);
  }

  /* Top border */
  if (rect.y > 0) {
    XFillRectangle (ximagesink->xcontext->disp, xwindow->win, xwindow->gc,
        0, 0, xwindow->width, rect.y);
  }

  /* Bottom border */
  if ((rect.y + rect.h) < xwindow->height) {
    XFillRectangle (ximagesink->xcontext->disp, xwindow->win, xwindow->gc,
        0, rect.y + rect.h, xwindow->width, xwindow->height);
  }
}

/* This function puts a GstXImageBuffer on a GstXImageSink's window */
static gboolean
gst_x_image_sink_ximage_put (GstXImageSink * ximagesink, GstBuffer * ximage)
{
  GstXImageMemory *mem;
  GstVideoCropMeta *crop;
  GstVideoRectangle src = { 0, };
  GstVideoRectangle dst = { 0, };
  GstVideoRectangle result;
  gboolean draw_border = FALSE;

  /* We take the flow_lock. If expose is in there we don't want to run
     concurrently from the data flow thread */
  g_mutex_lock (&ximagesink->flow_lock);

  if (G_UNLIKELY (ximagesink->xwindow == NULL)) {
    g_mutex_unlock (&ximagesink->flow_lock);
    return FALSE;
  }

  /* Draw borders when displaying the first frame. After this
     draw borders only on expose event or caps change (ximagesink->draw_border = TRUE). */
  if (!ximagesink->cur_image || ximagesink->draw_border) {
    draw_border = TRUE;
  }

  /* Store a reference to the last image we put, lose the previous one */
  if (ximage && ximagesink->cur_image != ximage) {
    if (ximagesink->cur_image) {
      GST_LOG_OBJECT (ximagesink, "unreffing %p", ximagesink->cur_image);
      gst_buffer_unref (ximagesink->cur_image);
    }
    GST_LOG_OBJECT (ximagesink, "reffing %p as our current image", ximage);
    ximagesink->cur_image = gst_buffer_ref (ximage);
  }

  /* Expose sends a NULL image, we take the latest frame */
  if (!ximage) {
    draw_border = TRUE;
    if (ximagesink->cur_image) {
      ximage = ximagesink->cur_image;
    } else {
      g_mutex_unlock (&ximagesink->flow_lock);
      return TRUE;
    }
  }

  mem = (GstXImageMemory *) gst_buffer_peek_memory (ximage, 0);
  crop = gst_buffer_get_video_crop_meta (ximage);

  if (crop) {
    src.x = crop->x + mem->x;
    src.y = crop->y + mem->y;
    src.w = crop->width;
    src.h = crop->height;
    GST_LOG_OBJECT (ximagesink,
        "crop %dx%d-%dx%d", crop->x, crop->y, crop->width, crop->height);
  } else {
    src.x = mem->x;
    src.y = mem->y;
    src.w = mem->width;
    src.h = mem->height;
  }
  dst.w = ximagesink->xwindow->width;
  dst.h = ximagesink->xwindow->height;

  gst_video_sink_center_rect (src, dst, &result, FALSE);

  g_mutex_lock (&ximagesink->x_lock);

  if (draw_border) {
    gst_x_image_sink_xwindow_draw_borders (ximagesink, ximagesink->xwindow,
        result);
    ximagesink->draw_border = FALSE;
  }
#ifdef HAVE_XSHM
  if (ximagesink->xcontext->use_xshm) {
    GST_LOG_OBJECT (ximagesink,
        "XShmPutImage on %p, src: %d, %d - dest: %d, %d, dim: %dx%d, win %dx%d",
        ximage, 0, 0, result.x, result.y, result.w, result.h,
        ximagesink->xwindow->width, ximagesink->xwindow->height);
    XShmPutImage (ximagesink->xcontext->disp, ximagesink->xwindow->win,
        ximagesink->xwindow->gc, mem->ximage, src.x, src.y, result.x, result.y,
        result.w, result.h, FALSE);
  } else
#endif /* HAVE_XSHM */
  {
    GST_LOG_OBJECT (ximagesink,
        "XPutImage on %p, src: %d, %d - dest: %d, %d, dim: %dx%d, win %dx%d",
        ximage, 0, 0, result.x, result.y, result.w, result.h,
        ximagesink->xwindow->width, ximagesink->xwindow->height);
    XPutImage (ximagesink->xcontext->disp, ximagesink->xwindow->win,
        ximagesink->xwindow->gc, mem->ximage, src.x, src.y, result.x, result.y,
        result.w, result.h);
  }

  XSync (ximagesink->xcontext->disp, FALSE);

  g_mutex_unlock (&ximagesink->x_lock);

  g_mutex_unlock (&ximagesink->flow_lock);

  return TRUE;
}

static gboolean
gst_x_image_sink_xwindow_decorate (GstXImageSink * ximagesink,
    GstXWindow * window)
{
  Atom hints_atom = None;
  MotifWmHints *hints;

  g_return_val_if_fail (GST_IS_X_IMAGE_SINK (ximagesink), FALSE);
  g_return_val_if_fail (window != NULL, FALSE);

  g_mutex_lock (&ximagesink->x_lock);

  hints_atom = XInternAtom (ximagesink->xcontext->disp, "_MOTIF_WM_HINTS",
      True);
  if (hints_atom == None) {
    g_mutex_unlock (&ximagesink->x_lock);
    return FALSE;
  }

  hints = g_malloc0 (sizeof (MotifWmHints));

  hints->flags |= MWM_HINTS_DECORATIONS;
  hints->decorations = 1 << 0;

  XChangeProperty (ximagesink->xcontext->disp, window->win,
      hints_atom, hints_atom, 32, PropModeReplace,
      (guchar *) hints, sizeof (MotifWmHints) / sizeof (long));

  XSync (ximagesink->xcontext->disp, FALSE);

  g_mutex_unlock (&ximagesink->x_lock);

  g_free (hints);

  return TRUE;
}

static void
gst_x_image_sink_xwindow_set_title (GstXImageSink * ximagesink,
    GstXWindow * xwindow, const gchar * media_title)
{
  if (media_title) {
    g_free (ximagesink->media_title);
    ximagesink->media_title = g_strdup (media_title);
  }
  if (xwindow) {
    /* we have a window */
    if (xwindow->internal) {
      XTextProperty xproperty;
      XClassHint *hint = XAllocClassHint ();
      const gchar *app_name;
      const gchar *title = NULL;
      gchar *title_mem = NULL;

      /* set application name as a title */
      app_name = g_get_application_name ();

      if (app_name && ximagesink->media_title) {
        title = title_mem = g_strconcat (ximagesink->media_title, " : ",
            app_name, NULL);
      } else if (app_name) {
        title = app_name;
      } else if (ximagesink->media_title) {
        title = ximagesink->media_title;
      }

      if (title) {
        if ((XStringListToTextProperty (((char **) &title), 1,
                    &xproperty)) != 0) {
          XSetWMName (ximagesink->xcontext->disp, xwindow->win, &xproperty);
          XFree (xproperty.value);
        }

        g_free (title_mem);
      }

      if (hint) {
        hint->res_name = (char *) app_name;
        hint->res_class = (char *) "GStreamer";
        XSetClassHint (ximagesink->xcontext->disp, xwindow->win, hint);
      }
      XFree (hint);
    }
  }
}

/* This function handles a GstXWindow creation */
static GstXWindow *
gst_x_image_sink_xwindow_new (GstXImageSink * ximagesink, gint width,
    gint height)
{
  GstXWindow *xwindow = NULL;
  XGCValues values;

  g_return_val_if_fail (GST_IS_X_IMAGE_SINK (ximagesink), NULL);

  xwindow = g_new0 (GstXWindow, 1);

  xwindow->width = width;
  xwindow->height = height;
  xwindow->internal = TRUE;

  g_mutex_lock (&ximagesink->x_lock);

  xwindow->win = XCreateSimpleWindow (ximagesink->xcontext->disp,
      ximagesink->xcontext->root,
      0, 0, width, height, 0, 0, ximagesink->xcontext->black);

  /* We have to do that to prevent X from redrawing the background on 
     ConfigureNotify. This takes away flickering of video when resizing. */
  XSetWindowBackgroundPixmap (ximagesink->xcontext->disp, xwindow->win, None);

  /* set application name as a title */
  gst_x_image_sink_xwindow_set_title (ximagesink, xwindow, NULL);

  if (ximagesink->handle_events) {
    Atom wm_delete;

    XSelectInput (ximagesink->xcontext->disp, xwindow->win, ExposureMask |
        StructureNotifyMask | PointerMotionMask | KeyPressMask |
        KeyReleaseMask | ButtonPressMask | ButtonReleaseMask);

    /* Tell the window manager we'd like delete client messages instead of
     * being killed */
    wm_delete = XInternAtom (ximagesink->xcontext->disp,
        "WM_DELETE_WINDOW", False);
    (void) XSetWMProtocols (ximagesink->xcontext->disp, xwindow->win,
        &wm_delete, 1);
  }

  xwindow->gc = XCreateGC (ximagesink->xcontext->disp, xwindow->win,
      0, &values);

  XMapRaised (ximagesink->xcontext->disp, xwindow->win);

  XSync (ximagesink->xcontext->disp, FALSE);

  g_mutex_unlock (&ximagesink->x_lock);

  gst_x_image_sink_xwindow_decorate (ximagesink, xwindow);

  gst_video_overlay_got_window_handle (GST_VIDEO_OVERLAY (ximagesink),
      xwindow->win);

  return xwindow;
}

/* This function destroys a GstXWindow */
static void
gst_x_image_sink_xwindow_destroy (GstXImageSink * ximagesink,
    GstXWindow * xwindow)
{
  g_return_if_fail (xwindow != NULL);
  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));

  g_mutex_lock (&ximagesink->x_lock);

  /* If we did not create that window we just free the GC and let it live */
  if (xwindow->internal)
    XDestroyWindow (ximagesink->xcontext->disp, xwindow->win);
  else
    XSelectInput (ximagesink->xcontext->disp, xwindow->win, 0);

  XFreeGC (ximagesink->xcontext->disp, xwindow->gc);

  XSync (ximagesink->xcontext->disp, FALSE);

  g_mutex_unlock (&ximagesink->x_lock);

  g_free (xwindow);
}

static void
gst_x_image_sink_xwindow_update_geometry (GstXImageSink * ximagesink)
{
  XWindowAttributes attr;
  gboolean reconfigure;

  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));

  /* Update the window geometry */
  g_mutex_lock (&ximagesink->x_lock);
  if (G_UNLIKELY (ximagesink->xwindow == NULL)) {
    g_mutex_unlock (&ximagesink->x_lock);
    return;
  }

  XGetWindowAttributes (ximagesink->xcontext->disp,
      ximagesink->xwindow->win, &attr);

  /* Check if we would suggest a different width/height now */
  reconfigure = (ximagesink->xwindow->width != attr.width)
      || (ximagesink->xwindow->height != attr.height);
  ximagesink->xwindow->width = attr.width;
  ximagesink->xwindow->height = attr.height;

  g_mutex_unlock (&ximagesink->x_lock);

  if (reconfigure)
    gst_pad_push_event (GST_BASE_SINK (ximagesink)->sinkpad,
        gst_event_new_reconfigure ());
}

static void
gst_x_image_sink_xwindow_clear (GstXImageSink * ximagesink,
    GstXWindow * xwindow)
{
  g_return_if_fail (xwindow != NULL);
  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));

  g_mutex_lock (&ximagesink->x_lock);

  XSetForeground (ximagesink->xcontext->disp, xwindow->gc,
      ximagesink->xcontext->black);

  XFillRectangle (ximagesink->xcontext->disp, xwindow->win, xwindow->gc,
      0, 0, xwindow->width, xwindow->height);

  XSync (ximagesink->xcontext->disp, FALSE);

  g_mutex_unlock (&ximagesink->x_lock);
}

/* This function handles XEvents that might be in the queue. It generates
   GstEvent that will be sent upstream in the pipeline to handle interactivity
   and navigation.*/
static void
gst_x_image_sink_handle_xevents (GstXImageSink * ximagesink)
{
  XEvent e;
  gint pointer_x = 0, pointer_y = 0;
  gboolean pointer_moved = FALSE;
  gboolean exposed = FALSE, configured = FALSE;

  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));

  /* Then we get all pointer motion events, only the last position is
     interesting. */
  g_mutex_lock (&ximagesink->flow_lock);
  g_mutex_lock (&ximagesink->x_lock);
  while (XCheckWindowEvent (ximagesink->xcontext->disp,
          ximagesink->xwindow->win, PointerMotionMask, &e)) {
    g_mutex_unlock (&ximagesink->x_lock);
    g_mutex_unlock (&ximagesink->flow_lock);

    switch (e.type) {
      case MotionNotify:
        pointer_x = e.xmotion.x;
        pointer_y = e.xmotion.y;
        pointer_moved = TRUE;
        break;
      default:
        break;
    }
    g_mutex_lock (&ximagesink->flow_lock);
    g_mutex_lock (&ximagesink->x_lock);
  }

  if (pointer_moved) {
    g_mutex_unlock (&ximagesink->x_lock);
    g_mutex_unlock (&ximagesink->flow_lock);

    GST_DEBUG ("ximagesink pointer moved over window at %d,%d",
        pointer_x, pointer_y);
    gst_navigation_send_mouse_event (GST_NAVIGATION (ximagesink),
        "mouse-move", 0, pointer_x, pointer_y);

    g_mutex_lock (&ximagesink->flow_lock);
    g_mutex_lock (&ximagesink->x_lock);
  }

  /* We get all remaining events on our window to throw them upstream */
  while (XCheckWindowEvent (ximagesink->xcontext->disp,
          ximagesink->xwindow->win,
          KeyPressMask | KeyReleaseMask |
          ButtonPressMask | ButtonReleaseMask, &e)) {
    KeySym keysym;
    const char *key_str = NULL;

    /* We lock only for the X function call */
    g_mutex_unlock (&ximagesink->x_lock);
    g_mutex_unlock (&ximagesink->flow_lock);

    switch (e.type) {
      case ButtonPress:
        /* Mouse button pressed/released over our window. We send upstream
           events for interactivity/navigation */
        GST_DEBUG ("ximagesink button %d pressed over window at %d,%d",
            e.xbutton.button, e.xbutton.x, e.xbutton.x);
        gst_navigation_send_mouse_event (GST_NAVIGATION (ximagesink),
            "mouse-button-press", e.xbutton.button, e.xbutton.x, e.xbutton.y);
        break;
      case ButtonRelease:
        GST_DEBUG ("ximagesink button %d release over window at %d,%d",
            e.xbutton.button, e.xbutton.x, e.xbutton.x);
        gst_navigation_send_mouse_event (GST_NAVIGATION (ximagesink),
            "mouse-button-release", e.xbutton.button, e.xbutton.x, e.xbutton.y);
        break;
      case KeyPress:
      case KeyRelease:
        /* Key pressed/released over our window. We send upstream
           events for interactivity/navigation */
        g_mutex_lock (&ximagesink->x_lock);
        if (ximagesink->xcontext->use_xkb) {
          keysym = XkbKeycodeToKeysym (ximagesink->xcontext->disp,
              e.xkey.keycode, 0, 0);
        } else {
          keysym = XKeycodeToKeysym (ximagesink->xcontext->disp,
              e.xkey.keycode, 0);
        }
        if (keysym != NoSymbol) {
          key_str = XKeysymToString (keysym);
        } else {
          key_str = "unknown";
        }
        g_mutex_unlock (&ximagesink->x_lock);
        GST_DEBUG_OBJECT (ximagesink,
            "key %d pressed over window at %d,%d (%s)",
            e.xkey.keycode, e.xkey.x, e.xkey.y, key_str);
        gst_navigation_send_key_event (GST_NAVIGATION (ximagesink),
            e.type == KeyPress ? "key-press" : "key-release", key_str);
        break;
      default:
        GST_DEBUG_OBJECT (ximagesink, "ximagesink unhandled X event (%d)",
            e.type);
    }
    g_mutex_lock (&ximagesink->flow_lock);
    g_mutex_lock (&ximagesink->x_lock);
  }

  /* Handle Expose */
  while (XCheckWindowEvent (ximagesink->xcontext->disp,
          ximagesink->xwindow->win, ExposureMask | StructureNotifyMask, &e)) {
    switch (e.type) {
      case Expose:
        exposed = TRUE;
        break;
      case ConfigureNotify:
        g_mutex_unlock (&ximagesink->x_lock);
        gst_x_image_sink_xwindow_update_geometry (ximagesink);
        g_mutex_lock (&ximagesink->x_lock);
        configured = TRUE;
        break;
      default:
        break;
    }
  }

  if (ximagesink->handle_expose && (exposed || configured)) {
    g_mutex_unlock (&ximagesink->x_lock);
    g_mutex_unlock (&ximagesink->flow_lock);

    gst_x_image_sink_expose (GST_VIDEO_OVERLAY (ximagesink));

    g_mutex_lock (&ximagesink->flow_lock);
    g_mutex_lock (&ximagesink->x_lock);
  }

  /* Handle Display events */
  while (XPending (ximagesink->xcontext->disp)) {
    XNextEvent (ximagesink->xcontext->disp, &e);

    switch (e.type) {
      case ClientMessage:{
        Atom wm_delete;

        wm_delete = XInternAtom (ximagesink->xcontext->disp,
            "WM_DELETE_WINDOW", False);
        if (wm_delete == (Atom) e.xclient.data.l[0]) {
          /* Handle window deletion by posting an error on the bus */
          GST_ELEMENT_ERROR (ximagesink, RESOURCE, NOT_FOUND,
              ("Output window was closed"), (NULL));

          g_mutex_unlock (&ximagesink->x_lock);
          gst_x_image_sink_xwindow_destroy (ximagesink, ximagesink->xwindow);
          ximagesink->xwindow = NULL;
          g_mutex_lock (&ximagesink->x_lock);
        }
        break;
      }
      default:
        break;
    }
  }

  g_mutex_unlock (&ximagesink->x_lock);
  g_mutex_unlock (&ximagesink->flow_lock);
}

static gpointer
gst_x_image_sink_event_thread (GstXImageSink * ximagesink)
{
  g_return_val_if_fail (GST_IS_X_IMAGE_SINK (ximagesink), NULL);

  GST_OBJECT_LOCK (ximagesink);
  while (ximagesink->running) {
    GST_OBJECT_UNLOCK (ximagesink);

    if (ximagesink->xwindow) {
      gst_x_image_sink_handle_xevents (ximagesink);
    }
    /* FIXME: do we want to align this with the framerate or anything else? */
    g_usleep (G_USEC_PER_SEC / 20);

    GST_OBJECT_LOCK (ximagesink);
  }
  GST_OBJECT_UNLOCK (ximagesink);

  return NULL;
}

static void
gst_x_image_sink_manage_event_thread (GstXImageSink * ximagesink)
{
  GThread *thread = NULL;

  /* don't start the thread too early */
  if (ximagesink->xcontext == NULL) {
    return;
  }

  GST_OBJECT_LOCK (ximagesink);
  if (ximagesink->handle_expose || ximagesink->handle_events) {
    if (!ximagesink->event_thread) {
      /* Setup our event listening thread */
      GST_DEBUG_OBJECT (ximagesink, "run xevent thread, expose %d, events %d",
          ximagesink->handle_expose, ximagesink->handle_events);
      ximagesink->running = TRUE;
      ximagesink->event_thread = g_thread_try_new ("ximagesink-events",
          (GThreadFunc) gst_x_image_sink_event_thread, ximagesink, NULL);
    }
  } else {
    if (ximagesink->event_thread) {
      GST_DEBUG_OBJECT (ximagesink, "stop xevent thread, expose %d, events %d",
          ximagesink->handle_expose, ximagesink->handle_events);
      ximagesink->running = FALSE;
      /* grab thread and mark it as NULL */
      thread = ximagesink->event_thread;
      ximagesink->event_thread = NULL;
    }
  }
  GST_OBJECT_UNLOCK (ximagesink);

  /* Wait for our event thread to finish */
  if (thread)
    g_thread_join (thread);

}


/* This function calculates the pixel aspect ratio based on the properties
 * in the xcontext structure and stores it there. */
static void
gst_x_image_sink_calculate_pixel_aspect_ratio (GstXContext * xcontext)
{
  static const gint par[][2] = {
    {1, 1},                     /* regular screen */
    {16, 15},                   /* PAL TV */
    {11, 10},                   /* 525 line Rec.601 video */
    {54, 59},                   /* 625 line Rec.601 video */
    {64, 45},                   /* 1280x1024 on 16:9 display */
    {5, 3},                     /* 1280x1024 on 4:3 display */
    {4, 3}                      /*  800x600 on 16:9 display */
  };
  gint i;
  gint index;
  gdouble ratio;
  gdouble delta;

#define DELTA(idx) (ABS (ratio - ((gdouble) par[idx][0] / par[idx][1])))

  /* first calculate the "real" ratio based on the X values;
   * which is the "physical" w/h divided by the w/h in pixels of the display */
  ratio = (gdouble) (xcontext->widthmm * xcontext->height)
      / (xcontext->heightmm * xcontext->width);

  /* DirectFB's X in 720x576 reports the physical dimensions wrong, so
   * override here */
  if (xcontext->width == 720 && xcontext->height == 576) {
    ratio = 4.0 * 576 / (3.0 * 720);
  }
  GST_DEBUG ("calculated pixel aspect ratio: %f", ratio);

  /* now find the one from par[][2] with the lowest delta to the real one */
  delta = DELTA (0);
  index = 0;

  for (i = 1; i < sizeof (par) / (sizeof (gint) * 2); ++i) {
    gdouble this_delta = DELTA (i);

    if (this_delta < delta) {
      index = i;
      delta = this_delta;
    }
  }

  GST_DEBUG ("Decided on index %d (%d/%d)", index,
      par[index][0], par[index][1]);

  g_free (xcontext->par);
  xcontext->par = g_new0 (GValue, 1);
  g_value_init (xcontext->par, GST_TYPE_FRACTION);
  gst_value_set_fraction (xcontext->par, par[index][0], par[index][1]);
  GST_DEBUG ("set xcontext PAR to %d/%d",
      gst_value_get_fraction_numerator (xcontext->par),
      gst_value_get_fraction_denominator (xcontext->par));
}

/* This function gets the X Display and global info about it. Everything is
   stored in our object and will be cleaned when the object is disposed. Note
   here that caps for supported format are generated without any window or
   image creation */
static GstXContext *
gst_x_image_sink_xcontext_get (GstXImageSink * ximagesink)
{
  GstXContext *xcontext = NULL;
  XPixmapFormatValues *px_formats = NULL;
  gint nb_formats = 0, i;
  gint endianness;
  GstVideoFormat vformat;
  guint32 alpha_mask;
  int opcode, event, err;
  int major = XkbMajorVersion;
  int minor = XkbMinorVersion;

  g_return_val_if_fail (GST_IS_X_IMAGE_SINK (ximagesink), NULL);

  xcontext = g_new0 (GstXContext, 1);

  g_mutex_lock (&ximagesink->x_lock);

  xcontext->disp = XOpenDisplay (ximagesink->display_name);

  if (!xcontext->disp) {
    g_mutex_unlock (&ximagesink->x_lock);
    g_free (xcontext);
    GST_ELEMENT_ERROR (ximagesink, RESOURCE, WRITE,
        ("Could not initialise X output"), ("Could not open display"));
    return NULL;
  }

  xcontext->screen = DefaultScreenOfDisplay (xcontext->disp);
  xcontext->screen_num = DefaultScreen (xcontext->disp);
  xcontext->visual = DefaultVisual (xcontext->disp, xcontext->screen_num);
  xcontext->root = DefaultRootWindow (xcontext->disp);
  xcontext->white = XWhitePixel (xcontext->disp, xcontext->screen_num);
  xcontext->black = XBlackPixel (xcontext->disp, xcontext->screen_num);
  xcontext->depth = DefaultDepthOfScreen (xcontext->screen);

  xcontext->width = DisplayWidth (xcontext->disp, xcontext->screen_num);
  xcontext->height = DisplayHeight (xcontext->disp, xcontext->screen_num);
  xcontext->widthmm = DisplayWidthMM (xcontext->disp, xcontext->screen_num);
  xcontext->heightmm = DisplayHeightMM (xcontext->disp, xcontext->screen_num);

  GST_DEBUG_OBJECT (ximagesink, "X reports %dx%d pixels and %d mm x %d mm",
      xcontext->width, xcontext->height, xcontext->widthmm, xcontext->heightmm);

  gst_x_image_sink_calculate_pixel_aspect_ratio (xcontext);

  /* We get supported pixmap formats at supported depth */
  px_formats = XListPixmapFormats (xcontext->disp, &nb_formats);

  if (!px_formats) {
    XCloseDisplay (xcontext->disp);
    g_mutex_unlock (&ximagesink->x_lock);
    g_free (xcontext->par);
    g_free (xcontext);
    GST_ELEMENT_ERROR (ximagesink, RESOURCE, SETTINGS,
        ("Could not get supported pixmap formats"), (NULL));
    return NULL;
  }

  /* We get bpp value corresponding to our running depth */
  for (i = 0; i < nb_formats; i++) {
    if (px_formats[i].depth == xcontext->depth)
      xcontext->bpp = px_formats[i].bits_per_pixel;
  }

  XFree (px_formats);

  endianness = (ImageByteOrder (xcontext->disp) ==
      LSBFirst) ? G_LITTLE_ENDIAN : G_BIG_ENDIAN;

  /* Search for XShm extension support */
#ifdef HAVE_XSHM
  if (XShmQueryExtension (xcontext->disp) &&
      gst_x_image_sink_check_xshm_calls (ximagesink, xcontext)) {
    xcontext->use_xshm = TRUE;
    GST_DEBUG ("ximagesink is using XShm extension");
  } else
#endif /* HAVE_XSHM */
  {
    xcontext->use_xshm = FALSE;
    GST_DEBUG ("ximagesink is not using XShm extension");
  }
  if (XkbQueryExtension (xcontext->disp, &opcode, &event, &err, &major, &minor)) {
    xcontext->use_xkb = TRUE;
    GST_DEBUG ("ximagesink is using Xkb extension");
  } else {
    xcontext->use_xkb = FALSE;
    GST_DEBUG ("ximagesink is not using Xkb extension");
  }

  /* extrapolate alpha mask */
  if (xcontext->depth == 32) {
    alpha_mask = ~(xcontext->visual->red_mask
        | xcontext->visual->green_mask | xcontext->visual->blue_mask);
  } else {
    alpha_mask = 0;
  }

  vformat =
      gst_video_format_from_masks (xcontext->depth, xcontext->bpp, endianness,
      xcontext->visual->red_mask, xcontext->visual->green_mask,
      xcontext->visual->blue_mask, alpha_mask);

  if (vformat == GST_VIDEO_FORMAT_UNKNOWN)
    goto unknown_format;

  /* update object's par with calculated one if not set yet */
  if (!ximagesink->par) {
    ximagesink->par = g_new0 (GValue, 1);
    gst_value_init_and_copy (ximagesink->par, xcontext->par);
    GST_DEBUG_OBJECT (ximagesink, "set calculated PAR on object's PAR");
  }
  xcontext->caps = gst_caps_new_simple ("video/x-raw",
      "format", G_TYPE_STRING, gst_video_format_to_string (vformat),
      "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);
  if (ximagesink->par) {
    int nom, den;

    nom = gst_value_get_fraction_numerator (ximagesink->par);
    den = gst_value_get_fraction_denominator (ximagesink->par);
    gst_caps_set_simple (xcontext->caps, "pixel-aspect-ratio",
        GST_TYPE_FRACTION, nom, den, NULL);
  }

  g_mutex_unlock (&ximagesink->x_lock);

  return xcontext;

  /* ERRORS */
unknown_format:
  {
    GST_ERROR_OBJECT (ximagesink, "unknown format");
    return NULL;
  }
}

/* This function cleans the X context. Closing the Display and unrefing the
   caps for supported formats. */
static void
gst_x_image_sink_xcontext_clear (GstXImageSink * ximagesink)
{
  GstXContext *xcontext;

  g_return_if_fail (GST_IS_X_IMAGE_SINK (ximagesink));

  GST_OBJECT_LOCK (ximagesink);
  if (ximagesink->xcontext == NULL) {
    GST_OBJECT_UNLOCK (ximagesink);
    return;
  }

  /* Take the xcontext reference and NULL it while we
   * clean it up, so that any buffer-alloced buffers 
   * arriving after this will be freed correctly */
  xcontext = ximagesink->xcontext;
  ximagesink->xcontext = NULL;

  GST_OBJECT_UNLOCK (ximagesink);

  gst_caps_unref (xcontext->caps);
  g_free (xcontext->par);
  g_free (ximagesink->par);
  ximagesink->par = NULL;

  if (xcontext->last_caps)
    gst_caps_replace (&xcontext->last_caps, NULL);

  g_mutex_lock (&ximagesink->x_lock);

  XCloseDisplay (xcontext->disp);

  g_mutex_unlock (&ximagesink->x_lock);

  g_free (xcontext);
}

/* Element stuff */

static GstCaps *
gst_x_image_sink_getcaps (GstBaseSink * bsink, GstCaps * filter)
{
  GstXImageSink *ximagesink;
  GstCaps *caps;
  int i;

  ximagesink = GST_X_IMAGE_SINK (bsink);

  g_mutex_lock (&ximagesink->x_lock);
  if (ximagesink->xcontext) {
    GstCaps *caps;

    caps = gst_caps_ref (ximagesink->xcontext->caps);

    if (filter) {
      GstCaps *intersection;

      intersection =
          gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
      gst_caps_unref (caps);
      caps = intersection;
    }

    if (gst_caps_is_empty (caps)) {
      g_mutex_unlock (&ximagesink->x_lock);
      return caps;
    }

    if (ximagesink->xwindow && ximagesink->xwindow->width) {
      GstStructure *s0, *s1;

      caps = gst_caps_make_writable (caps);

      /* There can only be a single structure because the xcontext
       * caps only have a single structure */
      s0 = gst_caps_get_structure (caps, 0);
      s1 = gst_structure_copy (gst_caps_get_structure (caps, 0));

      gst_structure_set (s0, "width", G_TYPE_INT, ximagesink->xwindow->width,
          "height", G_TYPE_INT, ximagesink->xwindow->height, NULL);
      gst_caps_append_structure (caps, s1);

      /* This will not change the order but will remove the
       * fixed width/height caps again if not possible
       * upstream */
      if (filter) {
        GstCaps *intersection;

        intersection =
            gst_caps_intersect_full (caps, filter, GST_CAPS_INTERSECT_FIRST);
        gst_caps_unref (caps);
        caps = intersection;
      }
    }

    g_mutex_unlock (&ximagesink->x_lock);
    return caps;
  }
  g_mutex_unlock (&ximagesink->x_lock);

  /* get a template copy and add the pixel aspect ratio */
  caps = gst_pad_get_pad_template_caps (GST_BASE_SINK (ximagesink)->sinkpad);
  if (ximagesink->par) {
    caps = gst_caps_make_writable (caps);
    for (i = 0; i < gst_caps_get_size (caps); ++i) {
      GstStructure *structure = gst_caps_get_structure (caps, i);
      int nom, den;

      nom = gst_value_get_fraction_numerator (ximagesink->par);
      den = gst_value_get_fraction_denominator (ximagesink->par);
      gst_structure_set (structure, "pixel-aspect-ratio",
          GST_TYPE_FRACTION, nom, den, NULL);
    }
  }

  if (filter) {
    GstCaps *intersection;

    intersection =
        gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
    gst_caps_unref (caps);
    caps = intersection;
  }

  return caps;
}

static GstBufferPool *
gst_x_image_sink_create_pool (GstXImageSink * ximagesink, GstCaps * caps,
    gsize size, gint min)
{
  static GstAllocationParams params = { 0, 15, 0, 0, };
  GstBufferPool *pool;
  GstStructure *config;

  /* create a new pool for the new configuration */
  pool = gst_ximage_buffer_pool_new (ximagesink);

  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_set_params (config, caps, size, min, 0);
  gst_buffer_pool_config_set_allocator (config, NULL, &params);

  if (!gst_buffer_pool_set_config (pool, config))
    goto config_failed;

  return pool;

config_failed:
  {
    GST_WARNING_OBJECT (ximagesink, "failed setting config");
    gst_object_unref (pool);
    return NULL;
  }
}

static gboolean
gst_x_image_sink_setcaps (GstBaseSink * bsink, GstCaps * caps)
{
  GstXImageSink *ximagesink;
  GstStructure *structure;
  GstVideoInfo info;
  GstBufferPool *newpool, *oldpool;
  const GValue *par;

  ximagesink = GST_X_IMAGE_SINK (bsink);

  if (!ximagesink->xcontext)
    return FALSE;

  GST_DEBUG_OBJECT (ximagesink,
      "sinkconnect possible caps %" GST_PTR_FORMAT " with given caps %"
      GST_PTR_FORMAT, ximagesink->xcontext->caps, caps);

  /* We intersect those caps with our template to make sure they are correct */
  if (!gst_caps_can_intersect (ximagesink->xcontext->caps, caps))
    goto incompatible_caps;

  if (!gst_video_info_from_caps (&info, caps))
    goto invalid_format;

  structure = gst_caps_get_structure (caps, 0);
  /* if the caps contain pixel-aspect-ratio, they have to match ours,
   * otherwise linking should fail */
  par = gst_structure_get_value (structure, "pixel-aspect-ratio");
  if (par) {
    if (ximagesink->par) {
      if (gst_value_compare (par, ximagesink->par) != GST_VALUE_EQUAL) {
        goto wrong_aspect;
      }
    } else if (ximagesink->xcontext->par) {
      if (gst_value_compare (par, ximagesink->xcontext->par) != GST_VALUE_EQUAL) {
        goto wrong_aspect;
      }
    }
  }

  GST_VIDEO_SINK_WIDTH (ximagesink) = info.width;
  GST_VIDEO_SINK_HEIGHT (ximagesink) = info.height;
  ximagesink->fps_n = info.fps_n;
  ximagesink->fps_d = info.fps_d;

  /* Notify application to set xwindow id now */
  g_mutex_lock (&ximagesink->flow_lock);
  if (!ximagesink->xwindow) {
    g_mutex_unlock (&ximagesink->flow_lock);
    gst_video_overlay_prepare_window_handle (GST_VIDEO_OVERLAY (ximagesink));
  } else {
    g_mutex_unlock (&ximagesink->flow_lock);
  }

  /* Creating our window and our image */
  if (GST_VIDEO_SINK_WIDTH (ximagesink) <= 0 ||
      GST_VIDEO_SINK_HEIGHT (ximagesink) <= 0)
    goto invalid_size;

  g_mutex_lock (&ximagesink->flow_lock);
  if (!ximagesink->xwindow) {
    ximagesink->xwindow = gst_x_image_sink_xwindow_new (ximagesink,
        GST_VIDEO_SINK_WIDTH (ximagesink), GST_VIDEO_SINK_HEIGHT (ximagesink));
  }

  ximagesink->info = info;

  /* Remember to draw borders for next frame */
  ximagesink->draw_border = TRUE;

  /* create a new internal pool for the new configuration */
  newpool = gst_x_image_sink_create_pool (ximagesink, caps, info.size, 2);

  /* we don't activate the internal pool yet as it may not be needed */
  oldpool = ximagesink->pool;
  ximagesink->pool = newpool;
  g_mutex_unlock (&ximagesink->flow_lock);

  /* deactivate and unref the old internal pool */
  if (oldpool) {
    gst_buffer_pool_set_active (oldpool, FALSE);
    gst_object_unref (oldpool);
  }

  return TRUE;

  /* ERRORS */
incompatible_caps:
  {
    GST_ERROR_OBJECT (ximagesink, "caps incompatible");
    return FALSE;
  }
invalid_format:
  {
    GST_ERROR_OBJECT (ximagesink, "caps invalid");
    return FALSE;
  }
wrong_aspect:
  {
    GST_INFO_OBJECT (ximagesink, "pixel aspect ratio does not match");
    return FALSE;
  }
invalid_size:
  {
    GST_ELEMENT_ERROR (ximagesink, CORE, NEGOTIATION, (NULL),
        ("Invalid image size."));
    return FALSE;
  }
}

static GstStateChangeReturn
gst_x_image_sink_change_state (GstElement * element, GstStateChange transition)
{
  GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
  GstXImageSink *ximagesink;
  GstXContext *xcontext = NULL;

  ximagesink = GST_X_IMAGE_SINK (element);

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      /* Initializing the XContext */
      if (ximagesink->xcontext == NULL) {
        xcontext = gst_x_image_sink_xcontext_get (ximagesink);
        if (xcontext == NULL) {
          ret = GST_STATE_CHANGE_FAILURE;
          goto beach;
        }
        GST_OBJECT_LOCK (ximagesink);
        if (xcontext)
          ximagesink->xcontext = xcontext;
        GST_OBJECT_UNLOCK (ximagesink);
      }

      /* call XSynchronize with the current value of synchronous */
      GST_DEBUG_OBJECT (ximagesink, "XSynchronize called with %s",
          ximagesink->synchronous ? "TRUE" : "FALSE");
      g_mutex_lock (&ximagesink->x_lock);
      XSynchronize (ximagesink->xcontext->disp, ximagesink->synchronous);
      g_mutex_unlock (&ximagesink->x_lock);
      gst_x_image_sink_manage_event_thread (ximagesink);
      break;
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      g_mutex_lock (&ximagesink->flow_lock);
      if (ximagesink->xwindow)
        gst_x_image_sink_xwindow_clear (ximagesink, ximagesink->xwindow);
      g_mutex_unlock (&ximagesink->flow_lock);
      break;
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
      break;
    default:
      break;
  }

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

  switch (transition) {
    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      ximagesink->fps_n = 0;
      ximagesink->fps_d = 1;
      GST_VIDEO_SINK_WIDTH (ximagesink) = 0;
      GST_VIDEO_SINK_HEIGHT (ximagesink) = 0;
      g_mutex_lock (&ximagesink->flow_lock);
      if (ximagesink->pool)
        gst_buffer_pool_set_active (ximagesink->pool, FALSE);
      g_mutex_unlock (&ximagesink->flow_lock);
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      gst_x_image_sink_reset (ximagesink);
      break;
    default:
      break;
  }

beach:
  return ret;
}

static void
gst_x_image_sink_get_times (GstBaseSink * bsink, GstBuffer * buf,
    GstClockTime * start, GstClockTime * end)
{
  GstXImageSink *ximagesink;

  ximagesink = GST_X_IMAGE_SINK (bsink);

  if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) {
    *start = GST_BUFFER_TIMESTAMP (buf);
    if (GST_BUFFER_DURATION_IS_VALID (buf)) {
      *end = *start + GST_BUFFER_DURATION (buf);
    } else {
      if (ximagesink->fps_n > 0) {
        *end = *start +
            gst_util_uint64_scale_int (GST_SECOND, ximagesink->fps_d,
            ximagesink->fps_n);
      }
    }
  }
}

static GstFlowReturn
gst_x_image_sink_show_frame (GstVideoSink * vsink, GstBuffer * buf)
{
  GstFlowReturn res;
  GstXImageSink *ximagesink;
  GstXImageMemory *mem;
  GstBuffer *to_put = NULL;

  ximagesink = GST_X_IMAGE_SINK (vsink);

  if (gst_buffer_n_memory (buf) == 1
      && (mem = (GstXImageMemory *) gst_buffer_peek_memory (buf, 0))
      && g_strcmp0 (mem->parent.allocator->mem_type, "ximage") == 0
      && mem->sink == ximagesink) {
    /* If this buffer has been allocated using our buffer management we simply
       put the ximage which is in the PRIVATE pointer */
    GST_LOG_OBJECT (ximagesink, "buffer from our pool, writing directly");
    to_put = buf;
    res = GST_FLOW_OK;
  } else {
    GstVideoFrame src, dest;
    GstBufferPoolAcquireParams params = { 0, };

    /* Else we have to copy the data into our private image, */
    /* if we have one... */
    GST_LOG_OBJECT (ximagesink, "buffer not from our pool, copying");

    /* an internal pool should have been created in setcaps */
    if (G_UNLIKELY (ximagesink->pool == NULL))
      goto no_pool;

    if (!gst_buffer_pool_set_active (ximagesink->pool, TRUE))
      goto activate_failed;

    /* take a buffer from our pool, if there is no buffer in the pool something
     * is seriously wrong, waiting for the pool here might deadlock when we try
     * to go to PAUSED because we never flush the pool. */
    params.flags = GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT;
    res = gst_buffer_pool_acquire_buffer (ximagesink->pool, &to_put, &params);
    if (res != GST_FLOW_OK)
      goto no_buffer;

    GST_CAT_LOG_OBJECT (CAT_PERFORMANCE, ximagesink,
        "slow copy into bufferpool buffer %p", to_put);

    if (!gst_video_frame_map (&src, &ximagesink->info, buf, GST_MAP_READ))
      goto invalid_buffer;

    if (!gst_video_frame_map (&dest, &ximagesink->info, to_put, GST_MAP_WRITE)) {
      gst_video_frame_unmap (&src);
      goto invalid_buffer;
    }

    gst_video_frame_copy (&dest, &src);

    gst_video_frame_unmap (&dest);
    gst_video_frame_unmap (&src);
  }

  if (!gst_x_image_sink_ximage_put (ximagesink, to_put))
    goto no_window;

done:
  if (to_put != buf)
    gst_buffer_unref (to_put);

  return res;

  /* ERRORS */
no_pool:
  {
    GST_ELEMENT_ERROR (ximagesink, RESOURCE, WRITE,
        ("Internal error: can't allocate images"),
        ("We don't have a bufferpool negotiated"));
    return GST_FLOW_ERROR;
  }
no_buffer:
  {
    /* No image available. That's very bad ! */
    GST_WARNING_OBJECT (ximagesink, "could not create image");
    return GST_FLOW_OK;
  }
invalid_buffer:
  {
    /* No Window available to put our image into */
    GST_WARNING_OBJECT (ximagesink, "could not map image");
    res = GST_FLOW_OK;
    goto done;
  }
no_window:
  {
    /* No Window available to put our image into */
    GST_WARNING_OBJECT (ximagesink, "could not output image - no window");
    res = GST_FLOW_ERROR;
    goto done;
  }
activate_failed:
  {
    GST_ERROR_OBJECT (ximagesink, "failed to activate bufferpool.");
    res = GST_FLOW_ERROR;
    goto done;
  }
}

static gboolean
gst_x_image_sink_event (GstBaseSink * sink, GstEvent * event)
{
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (sink);

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_TAG:{
      GstTagList *l;
      gchar *title = NULL;

      gst_event_parse_tag (event, &l);
      gst_tag_list_get_string (l, GST_TAG_TITLE, &title);

      if (title) {
        GST_DEBUG_OBJECT (ximagesink, "got tags, title='%s'", title);
        gst_x_image_sink_xwindow_set_title (ximagesink, ximagesink->xwindow,
            title);

        g_free (title);
      }
      break;
    }
    default:
      break;
  }
  return GST_BASE_SINK_CLASS (parent_class)->event (sink, event);
}

static gboolean
gst_x_image_sink_propose_allocation (GstBaseSink * bsink, GstQuery * query)
{
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (bsink);
  GstBufferPool *pool = NULL;
  GstCaps *caps;
  GstVideoInfo info;
  guint size;
  gboolean need_pool;

  gst_query_parse_allocation (query, &caps, &need_pool);

  if (caps == NULL)
    goto no_caps;

  if (!gst_video_info_from_caps (&info, caps))
    goto invalid_caps;

  /* the normal size of a frame */
  size = info.size;

  if (need_pool) {
    pool = gst_x_image_sink_create_pool (ximagesink, caps, info.size, 0);

    if (pool == NULL)
      goto no_pool;
  }

  /* we need at least 2 buffer because we hold on to the last one */
  gst_query_add_allocation_pool (query, pool, size, 2, 0);
  if (pool)
    gst_object_unref (pool);

  /* we also support various metadata */
  gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL);
  gst_query_add_allocation_meta (query, GST_VIDEO_CROP_META_API_TYPE, NULL);

  return TRUE;

  /* ERRORS */
no_caps:
  {
    GST_DEBUG_OBJECT (bsink, "no caps specified");
    return FALSE;
  }
invalid_caps:
  {
    GST_DEBUG_OBJECT (bsink, "invalid caps specified");
    return FALSE;
  }
no_pool:
  {
    /* Already warned in create_pool */
    return FALSE;
  }
}

/* Interfaces stuff */
static void
gst_x_image_sink_navigation_send_event (GstNavigation * navigation,
    GstStructure * structure)
{
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (navigation);
  GstEvent *event = NULL;
  gint x_offset, y_offset;
  gdouble x, y;
  gboolean handled = FALSE;

  /* We are not converting the pointer coordinates as there's no hardware
     scaling done here. The only possible scaling is done by videoscale and
     videoscale will have to catch those events and transform the coordinates
     to match the applied scaling. So here we just add the offset if the image
     is centered in the window.  */

  /* We take the flow_lock while we look at the window */
  g_mutex_lock (&ximagesink->flow_lock);

  if (!ximagesink->xwindow) {
    g_mutex_unlock (&ximagesink->flow_lock);
    gst_structure_free (structure);
    return;
  }

  x_offset = ximagesink->xwindow->width - GST_VIDEO_SINK_WIDTH (ximagesink);
  y_offset = ximagesink->xwindow->height - GST_VIDEO_SINK_HEIGHT (ximagesink);

  g_mutex_unlock (&ximagesink->flow_lock);

  if (x_offset > 0 && gst_structure_get_double (structure, "pointer_x", &x)) {
    x -= x_offset / 2;
    gst_structure_set (structure, "pointer_x", G_TYPE_DOUBLE, x, NULL);
  }
  if (y_offset > 0 && gst_structure_get_double (structure, "pointer_y", &y)) {
    y -= y_offset / 2;
    gst_structure_set (structure, "pointer_y", G_TYPE_DOUBLE, y, NULL);
  }

  event = gst_event_new_navigation (structure);
  if (event) {
    gst_event_ref (event);
    handled = gst_pad_push_event (GST_VIDEO_SINK_PAD (ximagesink), event);

    if (!handled)
      gst_element_post_message (GST_ELEMENT_CAST (ximagesink),
          gst_navigation_message_new_event (GST_OBJECT_CAST (ximagesink),
              event));

    gst_event_unref (event);
  }
}

static void
gst_x_image_sink_navigation_init (GstNavigationInterface * iface)
{
  iface->send_event = gst_x_image_sink_navigation_send_event;
}

static void
gst_x_image_sink_set_window_handle (GstVideoOverlay * overlay, guintptr id)
{
  XID xwindow_id = id;
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (overlay);
  GstXWindow *xwindow = NULL;

  /* We acquire the stream lock while setting this window in the element.
     We are basically cleaning tons of stuff replacing the old window, putting
     images while we do that would surely crash */
  g_mutex_lock (&ximagesink->flow_lock);

  /* If we already use that window return */
  if (ximagesink->xwindow && (xwindow_id == ximagesink->xwindow->win)) {
    g_mutex_unlock (&ximagesink->flow_lock);
    return;
  }

  /* If the element has not initialized the X11 context try to do so */
  if (!ximagesink->xcontext &&
      !(ximagesink->xcontext = gst_x_image_sink_xcontext_get (ximagesink))) {
    g_mutex_unlock (&ximagesink->flow_lock);
    /* we have thrown a GST_ELEMENT_ERROR now */
    return;
  }

  /* If a window is there already we destroy it */
  if (ximagesink->xwindow) {
    gst_x_image_sink_xwindow_destroy (ximagesink, ximagesink->xwindow);
    ximagesink->xwindow = NULL;
  }

  /* If the xid is 0 we go back to an internal window */
  if (xwindow_id == 0) {
    /* If no width/height caps nego did not happen window will be created
       during caps nego then */
    if (GST_VIDEO_SINK_WIDTH (ximagesink) && GST_VIDEO_SINK_HEIGHT (ximagesink)) {
      xwindow = gst_x_image_sink_xwindow_new (ximagesink,
          GST_VIDEO_SINK_WIDTH (ximagesink),
          GST_VIDEO_SINK_HEIGHT (ximagesink));
    }
  } else {
    xwindow = g_new0 (GstXWindow, 1);

    xwindow->win = xwindow_id;

    /* We set the events we want to receive and create a GC. */
    g_mutex_lock (&ximagesink->x_lock);
    xwindow->internal = FALSE;
    if (ximagesink->handle_events) {
      XSelectInput (ximagesink->xcontext->disp, xwindow->win, ExposureMask |
          StructureNotifyMask | PointerMotionMask | KeyPressMask |
          KeyReleaseMask);
    }

    xwindow->gc = XCreateGC (ximagesink->xcontext->disp, xwindow->win, 0, NULL);
    g_mutex_unlock (&ximagesink->x_lock);
  }

  if (xwindow) {
    ximagesink->xwindow = xwindow;
    /* Update the window geometry, possibly generating a reconfigure event. */
    gst_x_image_sink_xwindow_update_geometry (ximagesink);
  }

  g_mutex_unlock (&ximagesink->flow_lock);
}

static void
gst_x_image_sink_expose (GstVideoOverlay * overlay)
{
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (overlay);

  gst_x_image_sink_xwindow_update_geometry (ximagesink);
  gst_x_image_sink_ximage_put (ximagesink, NULL);
}

static void
gst_x_image_sink_set_event_handling (GstVideoOverlay * overlay,
    gboolean handle_events)
{
  GstXImageSink *ximagesink = GST_X_IMAGE_SINK (overlay);

  ximagesink->handle_events = handle_events;

  g_mutex_lock (&ximagesink->flow_lock);

  if (G_UNLIKELY (!ximagesink->xwindow)) {
    g_mutex_unlock (&ximagesink->flow_lock);
    return;
  }

  g_mutex_lock (&ximagesink->x_lock);

  if (handle_events) {
    if (ximagesink->xwindow->internal) {
      XSelectInput (ximagesink->xcontext->disp, ximagesink->xwindow->win,
          ExposureMask | StructureNotifyMask | PointerMotionMask |
          KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask);
    } else {
      XSelectInput (ximagesink->xcontext->disp, ximagesink->xwindow->win,
          ExposureMask | StructureNotifyMask | PointerMotionMask |
          KeyPressMask | KeyReleaseMask);
    }
  } else {
    XSelectInput (ximagesink->xcontext->disp, ximagesink->xwindow->win, 0);
  }

  g_mutex_unlock (&ximagesink->x_lock);

  g_mutex_unlock (&ximagesink->flow_lock);
}

static void
gst_x_image_sink_video_overlay_init (GstVideoOverlayInterface * iface)
{
  iface->set_window_handle = gst_x_image_sink_set_window_handle;
  iface->expose = gst_x_image_sink_expose;
  iface->handle_events = gst_x_image_sink_set_event_handling;
}

/* =========================================== */
/*                                             */
/*              Init & Class init              */
/*                                             */
/* =========================================== */

static void
gst_x_image_sink_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstXImageSink *ximagesink;

  g_return_if_fail (GST_IS_X_IMAGE_SINK (object));

  ximagesink = GST_X_IMAGE_SINK (object);

  switch (prop_id) {
    case PROP_DISPLAY:
      ximagesink->display_name = g_strdup (g_value_get_string (value));
      break;
    case PROP_SYNCHRONOUS:
      ximagesink->synchronous = g_value_get_boolean (value);
      if (ximagesink->xcontext) {
        GST_DEBUG_OBJECT (ximagesink, "XSynchronize called with %s",
            ximagesink->synchronous ? "TRUE" : "FALSE");
        g_mutex_lock (&ximagesink->x_lock);
        XSynchronize (ximagesink->xcontext->disp, ximagesink->synchronous);
        g_mutex_unlock (&ximagesink->x_lock);
      }
      break;
    case PROP_FORCE_ASPECT_RATIO:
      ximagesink->keep_aspect = g_value_get_boolean (value);
      break;
    case PROP_PIXEL_ASPECT_RATIO:
    {
      GValue *tmp;

      tmp = g_new0 (GValue, 1);
      g_value_init (tmp, GST_TYPE_FRACTION);

      if (!g_value_transform (value, tmp)) {
        GST_WARNING_OBJECT (ximagesink,
            "Could not transform string to aspect ratio");
        g_free (tmp);
      } else {
        GST_DEBUG_OBJECT (ximagesink, "set PAR to %d/%d",
            gst_value_get_fraction_numerator (tmp),
            gst_value_get_fraction_denominator (tmp));
        g_free (ximagesink->par);
        ximagesink->par = tmp;
      }
    }
      break;
    case PROP_HANDLE_EVENTS:
      gst_x_image_sink_set_event_handling (GST_VIDEO_OVERLAY (ximagesink),
          g_value_get_boolean (value));
      gst_x_image_sink_manage_event_thread (ximagesink);
      break;
    case PROP_HANDLE_EXPOSE:
      ximagesink->handle_expose = g_value_get_boolean (value);
      gst_x_image_sink_manage_event_thread (ximagesink);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_x_image_sink_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstXImageSink *ximagesink;

  g_return_if_fail (GST_IS_X_IMAGE_SINK (object));

  ximagesink = GST_X_IMAGE_SINK (object);

  switch (prop_id) {
    case PROP_DISPLAY:
      g_value_set_string (value, ximagesink->display_name);
      break;
    case PROP_SYNCHRONOUS:
      g_value_set_boolean (value, ximagesink->synchronous);
      break;
    case PROP_FORCE_ASPECT_RATIO:
      g_value_set_boolean (value, ximagesink->keep_aspect);
      break;
    case PROP_PIXEL_ASPECT_RATIO:
      if (ximagesink->par)
        g_value_transform (ximagesink->par, value);
      break;
    case PROP_HANDLE_EVENTS:
      g_value_set_boolean (value, ximagesink->handle_events);
      break;
    case PROP_HANDLE_EXPOSE:
      g_value_set_boolean (value, ximagesink->handle_expose);
      break;
    case PROP_WINDOW_WIDTH:
      if (ximagesink->xwindow)
        g_value_set_uint64 (value, ximagesink->xwindow->width);
      else
        g_value_set_uint64 (value, 0);
      break;
    case PROP_WINDOW_HEIGHT:
      if (ximagesink->xwindow)
        g_value_set_uint64 (value, ximagesink->xwindow->height);
      else
        g_value_set_uint64 (value, 0);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_x_image_sink_reset (GstXImageSink * ximagesink)
{
  GThread *thread;

  GST_OBJECT_LOCK (ximagesink);
  ximagesink->running = FALSE;
  /* grab thread and mark it as NULL */
  thread = ximagesink->event_thread;
  ximagesink->event_thread = NULL;
  GST_OBJECT_UNLOCK (ximagesink);

  /* Wait for our event thread to finish before we clean up our stuff. */
  if (thread)
    g_thread_join (thread);

  if (ximagesink->cur_image) {
    gst_buffer_unref (ximagesink->cur_image);
    ximagesink->cur_image = NULL;
  }

  g_mutex_lock (&ximagesink->flow_lock);

  if (ximagesink->pool) {
    gst_object_unref (ximagesink->pool);
    ximagesink->pool = NULL;
  }

  if (ximagesink->xwindow) {
    gst_x_image_sink_xwindow_clear (ximagesink, ximagesink->xwindow);
    gst_x_image_sink_xwindow_destroy (ximagesink, ximagesink->xwindow);
    ximagesink->xwindow = NULL;
  }
  g_mutex_unlock (&ximagesink->flow_lock);

  gst_x_image_sink_xcontext_clear (ximagesink);
}

static void
gst_x_image_sink_finalize (GObject * object)
{
  GstXImageSink *ximagesink;

  ximagesink = GST_X_IMAGE_SINK (object);

  gst_x_image_sink_reset (ximagesink);

  if (ximagesink->display_name) {
    g_free (ximagesink->display_name);
    ximagesink->display_name = NULL;
  }
  if (ximagesink->par) {
    g_free (ximagesink->par);
    ximagesink->par = NULL;
  }
  g_mutex_clear (&ximagesink->x_lock);
  g_mutex_clear (&ximagesink->flow_lock);

  g_free (ximagesink->media_title);

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gst_x_image_sink_init (GstXImageSink * ximagesink)
{
  ximagesink->display_name = NULL;
  ximagesink->xcontext = NULL;
  ximagesink->xwindow = NULL;
  ximagesink->cur_image = NULL;

  ximagesink->event_thread = NULL;
  ximagesink->running = FALSE;

  ximagesink->fps_n = 0;
  ximagesink->fps_d = 1;

  g_mutex_init (&ximagesink->x_lock);
  g_mutex_init (&ximagesink->flow_lock);

  ximagesink->par = NULL;

  ximagesink->pool = NULL;

  ximagesink->synchronous = FALSE;
  ximagesink->keep_aspect = TRUE;
  ximagesink->handle_events = TRUE;
  ximagesink->handle_expose = TRUE;
}

static void
gst_x_image_sink_class_init (GstXImageSinkClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;
  GstBaseSinkClass *gstbasesink_class;
  GstVideoSinkClass *videosink_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;
  gstbasesink_class = (GstBaseSinkClass *) klass;
  videosink_class = (GstVideoSinkClass *) klass;

  gobject_class->finalize = gst_x_image_sink_finalize;
  gobject_class->set_property = gst_x_image_sink_set_property;
  gobject_class->get_property = gst_x_image_sink_get_property;

  g_object_class_install_property (gobject_class, PROP_DISPLAY,
      g_param_spec_string ("display", "Display", "X Display name",
          NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_class, PROP_SYNCHRONOUS,
      g_param_spec_boolean ("synchronous", "Synchronous",
          "When enabled, runs the X display in synchronous mode. "
          "(unrelated to A/V sync, used only for debugging)", FALSE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_class, PROP_FORCE_ASPECT_RATIO,
      g_param_spec_boolean ("force-aspect-ratio", "Force aspect ratio",
          "When enabled, reverse caps negotiation (scaling) will respect "
          "original aspect ratio", TRUE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_class, PROP_PIXEL_ASPECT_RATIO,
      g_param_spec_string ("pixel-aspect-ratio", "Pixel Aspect Ratio",
          "The pixel aspect ratio of the device", "1/1",
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_class, PROP_HANDLE_EVENTS,
      g_param_spec_boolean ("handle-events", "Handle XEvents",
          "When enabled, XEvents will be selected and handled", TRUE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (gobject_class, PROP_HANDLE_EXPOSE,
      g_param_spec_boolean ("handle-expose", "Handle expose",
          "When enabled, "
          "the current frame will always be drawn in response to X Expose "
          "events", TRUE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstXImageSink:window-width
   *
   * Actual width of the video window.
   */
  g_object_class_install_property (gobject_class, PROP_WINDOW_WIDTH,
      g_param_spec_uint64 ("window-width", "window-width",
          "Width of the window", 0, G_MAXUINT64, 0,
          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));

  /**
   * GstXImageSink:window-height
   *
   * Actual height of the video window.
   */
  g_object_class_install_property (gobject_class, PROP_WINDOW_HEIGHT,
      g_param_spec_uint64 ("window-height", "window-height",
          "Height of the window", 0, G_MAXUINT64, 0,
          G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));

  gst_element_class_set_static_metadata (gstelement_class,
      "Video sink", "Sink/Video",
      "A standard X based videosink", "Julien Moutte <julien@moutte.net>");

  gst_element_class_add_static_pad_template (gstelement_class,
      &gst_x_image_sink_sink_template_factory);

  gstelement_class->change_state = gst_x_image_sink_change_state;

  gstbasesink_class->get_caps = GST_DEBUG_FUNCPTR (gst_x_image_sink_getcaps);
  gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_x_image_sink_setcaps);
  gstbasesink_class->get_times = GST_DEBUG_FUNCPTR (gst_x_image_sink_get_times);
  gstbasesink_class->propose_allocation =
      GST_DEBUG_FUNCPTR (gst_x_image_sink_propose_allocation);
  gstbasesink_class->event = GST_DEBUG_FUNCPTR (gst_x_image_sink_event);

  videosink_class->show_frame = GST_DEBUG_FUNCPTR (gst_x_image_sink_show_frame);
}