xvimagesink.c

/* GStreamer
 * Copyright (C) <2003> 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

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

/* Our interfaces */
#include <gst/interfaces/navigation.h>
#include <gst/interfaces/xoverlay.h>
#include <gst/interfaces/colorbalance.h>

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

/* Debugging category */
#include <gst/gstinfo.h>
GST_DEBUG_CATEGORY_STATIC (gst_debug_xvimagesink);
#define GST_CAT_DEFAULT gst_debug_xvimagesink

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_xvimage_buffer_finalize (GstXvImageBuffer * xvimage);

//static void gst_xvimagesink_send_pending_navigation (GstXvImageSink * xvimagesink);

/* ElementFactory information */
static GstElementDetails gst_xvimagesink_details =
GST_ELEMENT_DETAILS ("Video sink",
    "Sink/Video",
    "A Xv based videosink",
    "Julien Moutte <julien@moutte.net>");

/* Default template - initiated with class struct to allow gst-register to work
   without X running */
static GstStaticPadTemplate gst_xvimagesink_sink_template_factory =
    GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw-rgb, "
        "framerate = (double) [ 0.0, MAX ], "
        "width = (int) [ 1, MAX ], "
        "height = (int) [ 1, MAX ]; "
        "video/x-raw-yuv, "
        "framerate = (double) [ 0.0, MAX ], "
        "width = (int) [ 1, MAX ], " "height = (int) [ 1, MAX ]")
    );

enum
{
  ARG_0,
  ARG_CONTRAST,
  ARG_BRIGHTNESS,
  ARG_HUE,
  ARG_SATURATION,
  ARG_DISPLAY,
  ARG_SYNCHRONOUS,
  ARG_PIXEL_ASPECT_RATIO
      /* FILL ME */
};

static GstVideoSinkClass *parent_class = NULL;

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

/* xvimage buffers */

#define GST_TYPE_XVIMAGE_BUFFER (gst_xvimage_buffer_get_type())

#define GST_IS_XVIMAGE_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_XVIMAGE_BUFFER))
#define GST_XVIMAGE_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_XVIMAGE_BUFFER, GstXvImageBuffer))

/* This function destroys a GstXvImage handling XShm availability */
static void
gst_xvimage_buffer_destroy (GstXvImageBuffer * xvimage)
{
  GstXvImageSink *xvimagesink;

  xvimagesink = xvimage->xvimagesink;
  if (xvimagesink == NULL)
    goto no_sink;

  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

  /* If the destroyed image is the current one we destroy our reference too */
  if (xvimagesink->cur_image == xvimage)
    xvimagesink->cur_image = NULL;

  g_mutex_lock (xvimagesink->x_lock);

#ifdef HAVE_XSHM
  if (xvimagesink->xcontext->use_xshm) {
    if (xvimage->SHMInfo.shmaddr != ((void *) -1)) {
      XShmDetach (xvimagesink->xcontext->disp, &xvimage->SHMInfo);
      XSync (xvimagesink->xcontext->disp, FALSE);
      shmdt (xvimage->SHMInfo.shmaddr);
    }
    if (xvimage->SHMInfo.shmid > 0)
      shmctl (xvimage->SHMInfo.shmid, IPC_RMID, 0);
    if (xvimage->xvimage)
      XFree (xvimage->xvimage);
  } else
#endif /* HAVE_XSHM */
  {
    if (xvimage->xvimage) {
      if (xvimage->xvimage->data) {
        g_free (xvimage->xvimage->data);
      }
      XFree (xvimage->xvimage);
    }
  }

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

  g_mutex_unlock (xvimagesink->x_lock);

  xvimage->xvimagesink = NULL;
  gst_object_unref (xvimagesink);

  return;

no_sink:
  {
    GST_WARNING ("no sink found");
    return;
  }
}

static void
gst_xvimage_buffer_finalize (GstXvImageBuffer * xvimage)
{
  GstXvImageSink *xvimagesink;

  xvimagesink = xvimage->xvimagesink;
  if (xvimagesink == NULL)
    goto no_sink;

  /* If our geometry changed we can't reuse that image. */
  if ((xvimage->width != xvimagesink->video_width) ||
      (xvimage->height != xvimagesink->video_height)) {
    GST_DEBUG ("destroy image as its size changed %dx%d vs current %dx%d",
        xvimage->width, xvimage->height,
        xvimagesink->video_width, xvimagesink->video_height);
    gst_xvimage_buffer_destroy (xvimage);
  } else {
    /* In that case we can reuse the image and add it to our image pool. */
    GST_DEBUG ("recycling image in pool");
    /* need to increment the refcount again to recycle */
    gst_buffer_ref (GST_BUFFER (xvimage));
    g_mutex_lock (xvimagesink->pool_lock);
    xvimagesink->image_pool = g_slist_prepend (xvimagesink->image_pool,
        xvimage);
    g_mutex_unlock (xvimagesink->pool_lock);
  }
  return;

no_sink:
  {
    GST_WARNING ("no sink found");
    return;
  }
}

static void
gst_xvimage_buffer_free (GstXvImageBuffer * xvimage)
{
  /* make sure it is not recycled */
  xvimage->width = -1;
  xvimage->height = -1;
  gst_buffer_unref (GST_BUFFER (xvimage));
}

static void
gst_xvimage_buffer_init (GstXvImageBuffer * xvimage, gpointer g_class)
{
#ifdef HAVE_XSHM
  xvimage->SHMInfo.shmaddr = ((void *) -1);
  xvimage->SHMInfo.shmid = -1;
#endif
}

static void
gst_xvimage_buffer_class_init (gpointer g_class, gpointer class_data)
{
  GstMiniObjectClass *mini_object_class = GST_MINI_OBJECT_CLASS (g_class);

  mini_object_class->finalize = (GstMiniObjectFinalizeFunction)
      gst_xvimage_buffer_finalize;
}

GType
gst_xvimage_buffer_get_type (void)
{
  static GType _gst_xvimage_buffer_type;

  if (G_UNLIKELY (_gst_xvimage_buffer_type == 0)) {
    static const GTypeInfo xvimage_buffer_info = {
      sizeof (GstBufferClass),
      NULL,
      NULL,
      gst_xvimage_buffer_class_init,
      NULL,
      NULL,
      sizeof (GstXvImageBuffer),
      0,
      (GInstanceInitFunc) gst_xvimage_buffer_init,
      NULL
    };
    _gst_xvimage_buffer_type = g_type_register_static (GST_TYPE_BUFFER,
        "GstXvImageBuffer", &xvimage_buffer_info, 0);
  }
  return _gst_xvimage_buffer_type;
}

/* X11 stuff */

#ifdef HAVE_XSHM
static gboolean error_caught = FALSE;

static int
gst_xvimagesink_handle_xerror (Display * display, XErrorEvent * xevent)
{
  char error_msg[1024];

  XGetErrorText (display, xevent->error_code, error_msg, 1024);
  GST_DEBUG ("xvimagesink failed to use XShm calls. error: %s", error_msg);
  error_caught = TRUE;
  return 0;
}

/* This function checks that it is actually really possible to create an image
   using XShm */
static gboolean
gst_xvimagesink_check_xshm_calls (GstXContext * xcontext)
{
  XvImage *xvimage;
  XShmSegmentInfo SHMInfo;
  gint size;
  int (*handler) (Display *, XErrorEvent *);
  gboolean result = FALSE;

  g_return_val_if_fail (xcontext != NULL, FALSE);

  /* Setting an error handler to catch failure */
  error_caught = FALSE;
  handler = XSetErrorHandler (gst_xvimagesink_handle_xerror);

  /* Trying to create a 1x1 picture */
  GST_DEBUG ("XvShmCreateImage of 1x1");
  xvimage = XvShmCreateImage (xcontext->disp, xcontext->xv_port_id,
      xcontext->im_format, NULL, 1, 1, &SHMInfo);
  if (!xvimage) {
    GST_WARNING ("could not XvShmCreateImage a 1x1 image");
    goto beach;
  }
  size = xvimage->data_size;

  SHMInfo.shmid = shmget (IPC_PRIVATE, size, IPC_CREAT | 0777);
  if (SHMInfo.shmid == -1) {
    GST_WARNING ("could not get shared memory of %d bytes", size);
    goto beach;
  }

  SHMInfo.shmaddr = shmat (SHMInfo.shmid, 0, 0);
  if (SHMInfo.shmaddr == ((void *) -1)) {
    GST_WARNING ("Failed to shmat: %s", g_strerror (errno));
    goto beach;
  }

  xvimage->data = SHMInfo.shmaddr;
  SHMInfo.readOnly = FALSE;

  if (XShmAttach (xcontext->disp, &SHMInfo) == 0) {
    GST_WARNING ("Failed to XShmAttach");
    goto beach;
  }

  /* store whether we succeeded in result and reset error_caught */
  result = !error_caught;
  error_caught = FALSE;

beach:
  XSetErrorHandler (handler);

  XSync (xcontext->disp, FALSE);
  if (SHMInfo.shmaddr != ((void *) -1)) {
    XShmDetach (xcontext->disp, &SHMInfo);
    XSync (xcontext->disp, FALSE);
    shmdt (SHMInfo.shmaddr);
  }
  if (SHMInfo.shmid > 0)
    shmctl (SHMInfo.shmid, IPC_RMID, 0);
  if (xvimage)
    XFree (xvimage);
  return result;
}
#endif /* HAVE_XSHM */

/* This function handles GstXvImage creation depending on XShm availability */
static GstXvImageBuffer *
gst_xvimagesink_xvimage_new (GstXvImageSink * xvimagesink,
    gint width, gint height)
{
  GstXvImageBuffer *xvimage = NULL;
  gboolean succeeded = FALSE;

  g_return_val_if_fail (GST_IS_XVIMAGESINK (xvimagesink), NULL);
  GST_LOG_OBJECT (xvimagesink, "creating %dx%d", width, height);

  xvimage = (GstXvImageBuffer *) gst_mini_object_new (GST_TYPE_XVIMAGE_BUFFER);

  xvimage->width = width;
  xvimage->height = height;
  xvimage->im_format = xvimagesink->xcontext->im_format;
  xvimage->xvimagesink = gst_object_ref (xvimagesink);

  g_mutex_lock (xvimagesink->x_lock);

#ifdef HAVE_XSHM
  if (xvimagesink->xcontext->use_xshm) {
    xvimage->xvimage = XvShmCreateImage (xvimagesink->xcontext->disp,
        xvimagesink->xcontext->xv_port_id,
        xvimage->im_format, NULL,
        xvimage->width, xvimage->height, &xvimage->SHMInfo);
    if (!xvimage->xvimage) {
      GST_ELEMENT_ERROR (xvimagesink, RESOURCE, WRITE, (NULL),
          ("could not XvShmCreateImage a %dx%d image"));
      goto beach;
    }

    /* we have to use the returned data_size for our shm size */
    xvimage->size = xvimage->xvimage->data_size;
    GST_LOG_OBJECT (xvimagesink, "XShm image size is %d", xvimage->size);

    xvimage->SHMInfo.shmid = shmget (IPC_PRIVATE, xvimage->size,
        IPC_CREAT | 0777);
    if (xvimage->SHMInfo.shmid == -1) {
      GST_ELEMENT_ERROR (xvimagesink, RESOURCE, WRITE, (NULL),
          ("could not get shared memory of %d bytes", xvimage->size));
      goto beach;
    }

    xvimage->SHMInfo.shmaddr = shmat (xvimage->SHMInfo.shmid, 0, 0);
    if (xvimage->SHMInfo.shmaddr == ((void *) -1)) {
      GST_ELEMENT_ERROR (xvimagesink, RESOURCE, WRITE, (NULL),
          ("Failed to shmat: %s", g_strerror (errno)));
      goto beach;
    }

    xvimage->xvimage->data = xvimage->SHMInfo.shmaddr;
    xvimage->SHMInfo.readOnly = FALSE;

    if (XShmAttach (xvimagesink->xcontext->disp, &xvimage->SHMInfo) == 0) {
      GST_ELEMENT_ERROR (xvimagesink, RESOURCE, WRITE, (NULL),
          ("Failed to XShmAttach"));
      goto beach;
    }

    XSync (xvimagesink->xcontext->disp, FALSE);
  } else
#endif /* HAVE_XSHM */
  {
    xvimage->xvimage = XvCreateImage (xvimagesink->xcontext->disp,
        xvimagesink->xcontext->xv_port_id,
        xvimage->im_format, NULL, xvimage->width, xvimage->height);
    if (!xvimage->xvimage) {
      GST_ELEMENT_ERROR (xvimagesink, RESOURCE, WRITE, (NULL),
          ("could not XvCreateImage a %dx%d image"));
      goto beach;
    }

    /* we have to use the returned data_size for our image size */
    xvimage->size = xvimage->xvimage->data_size;
    xvimage->xvimage->data = g_malloc (xvimage->size);

    XSync (xvimagesink->xcontext->disp, FALSE);
  }
  succeeded = TRUE;

  GST_BUFFER_DATA (xvimage) = (guchar *) xvimage->xvimage->data;
  GST_BUFFER_SIZE (xvimage) = xvimage->size;

beach:
  g_mutex_unlock (xvimagesink->x_lock);

  if (!succeeded) {
    gst_xvimage_buffer_free (xvimage);
    xvimage = NULL;
  }

  return xvimage;
}

/* This function puts a GstXvImage on a GstXvImageSink's window */
static void
gst_xvimagesink_xvimage_put (GstXvImageSink * xvimagesink,
    GstXvImageBuffer * xvimage)
{
  g_return_if_fail (xvimage != NULL);
  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));
  g_return_if_fail (xvimagesink->xwindow != NULL);

  /* Store a reference to the last image we put */
  if (xvimagesink->cur_image != xvimage)
    xvimagesink->cur_image = xvimage;

  g_mutex_lock (xvimagesink->x_lock);

  /* We scale to the window's geometry */
#ifdef HAVE_XSHM
  if (xvimagesink->xcontext->use_xshm) {
    GST_LOG_OBJECT (xvimagesink,
        "XvShmPutImage with image %dx%d and window %dx%d",
        xvimage->width, xvimage->height,
        xvimagesink->xwindow->width, xvimagesink->xwindow->height);
    XvShmPutImage (xvimagesink->xcontext->disp,
        xvimagesink->xcontext->xv_port_id,
        xvimagesink->xwindow->win,
        xvimagesink->xwindow->gc, xvimage->xvimage,
        0, 0, xvimage->width, xvimage->height,
        0, 0, xvimagesink->xwindow->width, xvimagesink->xwindow->height, FALSE);
  } else
#endif /* HAVE_XSHM */
  {
    XvPutImage (xvimagesink->xcontext->disp,
        xvimagesink->xcontext->xv_port_id,
        xvimagesink->xwindow->win,
        xvimagesink->xwindow->gc, xvimage->xvimage,
        0, 0, xvimage->width, xvimage->height,
        0, 0, xvimagesink->xwindow->width, xvimagesink->xwindow->height);
  }

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

  g_mutex_unlock (xvimagesink->x_lock);
}

static gboolean
gst_xvimagesink_xwindow_decorate (GstXvImageSink * xvimagesink,
    GstXWindow * window)
{
  Atom hints_atom = None;
  MotifWmHints *hints;

  g_return_val_if_fail (GST_IS_XVIMAGESINK (xvimagesink), FALSE);
  g_return_val_if_fail (window != NULL, FALSE);

  g_mutex_lock (xvimagesink->x_lock);

  hints_atom = XInternAtom (xvimagesink->xcontext->disp, "_MOTIF_WM_HINTS", 1);
  if (hints_atom == None) {
    g_mutex_unlock (xvimagesink->x_lock);
    return FALSE;
  }

  hints = g_malloc0 (sizeof (MotifWmHints));

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

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

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

  g_mutex_unlock (xvimagesink->x_lock);

  g_free (hints);

  return TRUE;
}

/* This function handles a GstXWindow creation
 * The width and height are the actual pixel size on the display */
static GstXWindow *
gst_xvimagesink_xwindow_new (GstXvImageSink * xvimagesink,
    gint width, gint height)
{
  GstXWindow *xwindow = NULL;
  XGCValues values;

  g_return_val_if_fail (GST_IS_XVIMAGESINK (xvimagesink), NULL);

  xwindow = g_new0 (GstXWindow, 1);

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

  g_mutex_lock (xvimagesink->x_lock);

  xwindow->win = XCreateSimpleWindow (xvimagesink->xcontext->disp,
      xvimagesink->xcontext->root,
      0, 0, xwindow->width, xwindow->height,
      0, 0, xvimagesink->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 (xvimagesink->xcontext->disp, xwindow->win, None);

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

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

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

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

  g_mutex_unlock (xvimagesink->x_lock);

  gst_xvimagesink_xwindow_decorate (xvimagesink, xwindow);

  gst_x_overlay_got_xwindow_id (GST_X_OVERLAY (xvimagesink), xwindow->win);

  return xwindow;
}

/* This function destroys a GstXWindow */
static void
gst_xvimagesink_xwindow_destroy (GstXvImageSink * xvimagesink,
    GstXWindow * xwindow)
{
  g_return_if_fail (xwindow != NULL);
  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

  g_mutex_lock (xvimagesink->x_lock);

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

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

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

  g_mutex_unlock (xvimagesink->x_lock);

  g_free (xwindow);
}

/* This function resizes a GstXWindow.
 * The width and height are the actual pixel size on the display. */
static void
gst_xvimagesink_xwindow_resize (GstXvImageSink * xvimagesink,
    GstXWindow * xwindow, guint width, guint height)
{
  g_return_if_fail (xwindow != NULL);
  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

  g_mutex_lock (xvimagesink->x_lock);

  xwindow->width = width;
  xwindow->height = height;

  XResizeWindow (xvimagesink->xcontext->disp, xwindow->win,
      xwindow->width, xwindow->height);

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

  g_mutex_unlock (xvimagesink->x_lock);
}

static void
gst_xvimagesink_xwindow_clear (GstXvImageSink * xvimagesink,
    GstXWindow * xwindow)
{
  g_return_if_fail (xwindow != NULL);
  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

  g_mutex_lock (xvimagesink->x_lock);

  XvStopVideo (xvimagesink->xcontext->disp, xvimagesink->xcontext->xv_port_id,
      xwindow->win);

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

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

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

  g_mutex_unlock (xvimagesink->x_lock);
}

/* This function commits our internal colorbalance settings to our grabbed Xv
   port. If the xcontext is not initialized yet it simply returns */
static void
gst_xvimagesink_update_colorbalance (GstXvImageSink * xvimagesink)
{
  GList *channels = NULL;

  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

  /* If we haven't initialized the X context we can't update anything */
  if (xvimagesink->xcontext == NULL)
    return;

  /* For each channel of the colorbalance we calculate the correct value
     doing range conversion and then set the Xv port attribute to match our
     values. */
  channels = xvimagesink->xcontext->channels_list;

  while (channels) {
    if (channels->data && GST_IS_COLOR_BALANCE_CHANNEL (channels->data)) {
      GstColorBalanceChannel *channel = NULL;
      gint value = 0;
      gdouble convert_coef;

      channel = GST_COLOR_BALANCE_CHANNEL (channels->data);
      g_object_ref (channel);

      /* Our range conversion coef */
      convert_coef = (channel->max_value - channel->min_value) / 2000.0;

      if (g_ascii_strcasecmp (channel->label, "XV_HUE") == 0) {
        value = (xvimagesink->hue + 1000) * convert_coef + channel->min_value;
      } else if (g_ascii_strcasecmp (channel->label, "XV_SATURATION") == 0) {
        value = (xvimagesink->saturation + 1000) * convert_coef +
            channel->min_value;
      } else if (g_ascii_strcasecmp (channel->label, "XV_CONTRAST") == 0) {
        value = (xvimagesink->contrast + 1000) * convert_coef +
            channel->min_value;
      } else if (g_ascii_strcasecmp (channel->label, "XV_BRIGHTNESS") == 0) {
        value = (xvimagesink->brightness + 1000) * convert_coef +
            channel->min_value;
      } else {
        g_warning ("got an unknown channel %s", channel->label);
        g_object_unref (channel);
        return;
      }

      /* Committing to Xv port */
      g_mutex_lock (xvimagesink->x_lock);
      XvSetPortAttribute (xvimagesink->xcontext->disp,
          xvimagesink->xcontext->xv_port_id,
          XInternAtom (xvimagesink->xcontext->disp, channel->label, 1), value);
      g_mutex_unlock (xvimagesink->x_lock);

      g_object_unref (channel);
    }
    channels = g_list_next (channels);
  }
}

/* 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. It will also listen for configure events on the window to
   trigger caps renegotiation so on the fly software scaling can work. */
static void
gst_xvimagesink_handle_xevents (GstXvImageSink * xvimagesink, GstPad * pad)
{
  XEvent e;
  guint pointer_x = 0, pointer_y = 0;
  gboolean pointer_moved = FALSE;

  g_return_if_fail (GST_IS_XVIMAGESINK (xvimagesink));

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

  if (pointer_moved) {
    GST_DEBUG ("xvimagesink pointer moved over window at %d,%d",
        pointer_x, pointer_y);
    gst_navigation_send_mouse_event (GST_NAVIGATION (xvimagesink),
        "mouse-move", 0, e.xbutton.x, e.xbutton.y);
  }

  /* We get all events on our window to throw them upstream */
  g_mutex_lock (xvimagesink->x_lock);
  while (XCheckWindowEvent (xvimagesink->xcontext->disp,
          xvimagesink->xwindow->win,
          StructureNotifyMask | KeyPressMask |
          KeyReleaseMask | ButtonPressMask | ButtonReleaseMask, &e)) {
    KeySym keysym;

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

    switch (e.type) {
      case ConfigureNotify:
        /* Window got resized or moved. We update our data. */
        GST_DEBUG ("xvimagesink window is at %d, %d with geometry : %d,%d",
            e.xconfigure.x, e.xconfigure.y,
            e.xconfigure.width, e.xconfigure.height);
        xvimagesink->xwindow->width = e.xconfigure.width;
        xvimagesink->xwindow->height = e.xconfigure.height;
        break;
      case ButtonPress:
        /* Mouse button pressed over our window. We send upstream
           events for interactivity/navigation */
        GST_DEBUG ("xvimagesink button %d pressed over window at %d,%d",
            e.xbutton.button, e.xbutton.x, e.xbutton.y);
        gst_navigation_send_mouse_event (GST_NAVIGATION (xvimagesink),
            "mouse-button-press", e.xbutton.button, e.xbutton.x, e.xbutton.y);
        break;
      case ButtonRelease:
        /* Mouse button released over our window. We send upstream
           events for interactivity/navigation */
        GST_DEBUG ("xvimagesink button %d released over window at %d,%d",
            e.xbutton.button, e.xbutton.x, e.xbutton.y);
        gst_navigation_send_mouse_event (GST_NAVIGATION (xvimagesink),
            "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 */
        GST_DEBUG ("xvimagesink key %d pressed over window at %d,%d",
            e.xkey.keycode, e.xkey.x, e.xkey.y);
        keysym = XKeycodeToKeysym (xvimagesink->xcontext->disp,
            e.xkey.keycode, 0);
        if (keysym != NoSymbol) {
          gst_navigation_send_key_event (GST_NAVIGATION (xvimagesink),
              e.type == KeyPress ?
              "key-press" : "key-release", XKeysymToString (keysym));
        } else {
          gst_navigation_send_key_event (GST_NAVIGATION (xvimagesink),
              e.type == KeyPress ? "key-press" : "key-release", "unknown");
        }
        break;
      default:
        GST_DEBUG ("xvimagesink unhandled X event (%d)", e.type);
    }

    g_mutex_lock (xvimagesink->x_lock);
  }
  g_mutex_unlock (xvimagesink->x_lock);
}

/* This function generates a caps with all supported format by the first
   Xv grabable port we find. We store each one of the supported formats in a
   format list and append the format to a newly created caps that we return
   If this function does not return NULL because of an error, it also grabs
   the port via XvGrabPort */
static GstCaps *
gst_xvimagesink_get_xv_support (GstXvImageSink * xvimagesink,
    GstXContext * xcontext)
{
  gint i;
  guint nb_adaptors;
  XvAdaptorInfo *adaptors;
  gint nb_formats;
  XvImageFormatValues *formats = NULL;
  GstCaps *caps = NULL;

  g_return_val_if_fail (xcontext != NULL, NULL);

  /* First let's check that XVideo extension is available */
  if (!XQueryExtension (xcontext->disp, "XVideo", &i, &i, &i)) {
    GST_ELEMENT_ERROR (xvimagesink, RESOURCE, SETTINGS, (NULL),
        ("XVideo extension is not available"));
    return NULL;
  }

  /* Then we get adaptors list */
  if (Success != XvQueryAdaptors (xcontext->disp, xcontext->root,
          &nb_adaptors, &adaptors)) {
    GST_ELEMENT_ERROR (xvimagesink, RESOURCE, SETTINGS, (NULL),
        ("Failed getting XV adaptors list"));
    return NULL;
  }

  xcontext->xv_port_id = 0;

  GST_DEBUG ("Found %u XV adaptor(s)", nb_adaptors);

  /* Now search for an adaptor that supports XvImageMask */
  for (i = 0; i < nb_adaptors && !xcontext->xv_port_id; i++) {
    if (adaptors[i].type & XvImageMask) {
      gint j;

      /* We found such an adaptor, looking for an available port */
      for (j = 0; j < adaptors[i].num_ports && !xcontext->xv_port_id; j++) {
        /* We try to grab the port */
        if (Success == XvGrabPort (xcontext->disp, adaptors[i].base_id + j, 0)) {
          xcontext->xv_port_id = adaptors[i].base_id + j;
        }
      }
    }

    GST_DEBUG ("XV Adaptor %s with %ld ports", adaptors[i].name,
        adaptors[i].num_ports);

  }
  XvFreeAdaptorInfo (adaptors);

  if (!xcontext->xv_port_id) {
    GST_ELEMENT_ERROR (xvimagesink, RESOURCE, BUSY, (NULL),
        ("No port available"));
    return NULL;
  }

  /* Set XV_AUTOPAINT_COLORKEY */
  {
    int count;
    XvAttribute *const attr = XvQueryPortAttributes (xcontext->disp,
        xcontext->xv_port_id, &count);
    static const char autopaint[] = "XV_AUTOPAINT_COLORKEY";

    for (i = 0; i < count; i++)
      if (!strcmp (attr[i].name, autopaint)) {
        const Atom atom = XInternAtom (xcontext->disp, autopaint, False);

        XvSetPortAttribute (xcontext->disp, xcontext->xv_port_id, atom, 1);
        break;
      }

    XFree (attr);
  }

  /* We get all image formats supported by our port */
  formats = XvListImageFormats (xcontext->disp,
      xcontext->xv_port_id, &nb_formats);
  caps = gst_caps_new_empty ();
  for (i = 0; i < nb_formats; i++) {
    GstCaps *format_caps = NULL;

    /* We set the image format of the xcontext to an existing one. Sink
       connect method will override that but we need to have at least a
       valid image format so that we can make our xshm calls check before
       caps negotiation really happens. */
    xcontext->im_format = formats[i].id;

    switch (formats[i].type) {
      case XvRGB:
      {
        format_caps = gst_caps_new_simple ("video/x-raw-rgb",
            "endianness", G_TYPE_INT, xcontext->endianness,
            "depth", G_TYPE_INT, xcontext->depth,
            "bpp", G_TYPE_INT, xcontext->bpp,
            "blue_mask", G_TYPE_INT, formats[i].red_mask,
            "green_mask", G_TYPE_INT, formats[i].green_mask,
            "red_mask", G_TYPE_INT, formats[i].blue_mask,
            "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
            "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
            "framerate", GST_TYPE_DOUBLE_RANGE, 0.0, G_MAXDOUBLE, NULL);

        /* For RGB caps we store them and the image
           format so that we can get back the format
           when sinkconnect will give us a caps without
           format property */
        if (format_caps) {
          GstXvImageFormat *format = NULL;

          format = g_new0 (GstXvImageFormat, 1);
          if (format) {
            format->format = formats[i].id;
            format->caps = gst_caps_copy (format_caps);
            xcontext->formats_list =
                g_list_append (xcontext->formats_list, format);
          }
        }
        break;
      }
      case XvYUV:
        format_caps = gst_caps_new_simple ("video/x-raw-yuv",
            "format", GST_TYPE_FOURCC, formats[i].id,
            "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
            "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
            "framerate", GST_TYPE_DOUBLE_RANGE, 0.0, G_MAXDOUBLE, NULL);
        break;
      default:
        g_assert_not_reached ();
        break;
    }

    gst_caps_append (caps, format_caps);
  }

  if (formats)
    XFree (formats);

  GST_DEBUG ("Generated the following caps: %" GST_PTR_FORMAT, caps);

  if (gst_caps_is_empty (caps)) {
    gst_caps_unref (caps);
    XvUngrabPort (xcontext->disp, xcontext->xv_port_id, 0);
    GST_ELEMENT_ERROR (xvimagesink, STREAM, WRONG_TYPE, (NULL),
        ("No supported format found"));
    return NULL;
  }

  return caps;
}

/* This function calculates the pixel aspect ratio based on the properties
 * in the xcontext structure and stores it there. */
static void
gst_xvimagesink_calculate_pixel_aspect_ratio (GstXContext * xcontext)
{
  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 */
  };
  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_xvimagesink_xcontext_get (GstXvImageSink * xvimagesink)