--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/sys/v4l/gstv4lxoverlay.c	Wed Sep 01 12:16:41 2010 +0100
@@ -0,0 +1,245 @@
+/* GStreamer
+ *
+ * gstv4lxoverlay.c: X-based overlay interface implementation for V4L
+ *
+ * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.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
+
+#include <string.h>
+#include <sys/stat.h>
+
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xv.h>
+#include <X11/extensions/Xvlib.h>
+
+#include "gstv4lxoverlay.h"
+#include "gstv4lelement.h"
+#include "v4l_calls.h"
+
+GST_DEBUG_CATEGORY_STATIC (v4lxv_debug);
+#define GST_CAT_DEFAULT v4lxv_debug
+
+struct _GstV4lXv
+{
+  Display *dpy;
+  gint port, idle_id;
+  GMutex *mutex;
+};
+
+static void gst_v4l_xoverlay_set_xwindow_id (GstXOverlay * overlay,
+    XID xwindow_id);
+
+void
+gst_v4l_xoverlay_interface_init (GstXOverlayClass * klass)
+{
+  /* default virtual functions */
+  klass->set_xwindow_id = gst_v4l_xoverlay_set_xwindow_id;
+
+  GST_DEBUG_CATEGORY_INIT (v4lxv_debug, "v4lxv", 0,
+      "V4L XOverlay interface debugging");
+}
+
+static void
+gst_v4l_xoverlay_open (GstV4lElement * v4lelement)
+{
+  struct stat s;
+  GstV4lXv *v4lxv;
+  const gchar *name = g_getenv ("DISPLAY");
+  unsigned int ver, rel, req, ev, err, anum;
+  int i, id = 0, first_id = 0, min;
+  XvAdaptorInfo *ai;
+  Display *dpy;
+
+  /* we need a display, obviously */
+  if (!name || !(dpy = XOpenDisplay (name))) {
+    GST_WARNING ("No $DISPLAY set or failed to open - no overlay");
+    return;
+  }
+
+  /* First let's check that XVideo extension is available */
+  if (!XQueryExtension (dpy, "XVideo", &i, &i, &i)) {
+    GST_WARNING ("Xv extension not available - no overlay");
+    XCloseDisplay (dpy);
+    return;
+  }
+
+  /* find port that belongs to this device */
+  if (XvQueryExtension (dpy, &ver, &rel, &req, &ev, &err) != Success) {
+    GST_WARNING ("Xv extension not supported - no overlay");
+    XCloseDisplay (dpy);
+    return;
+  }
+  if (XvQueryAdaptors (dpy, DefaultRootWindow (dpy), &anum, &ai) != Success) {
+    GST_WARNING ("Failed to query Xv adaptors");
+    XCloseDisplay (dpy);
+    return;
+  }
+  if (fstat (v4lelement->video_fd, &s) < 0) {
+    GST_ERROR ("Failed to stat() file descriptor: %s", g_strerror (errno));
+    XCloseDisplay (dpy);
+    return;
+  }
+  min = s.st_rdev & 0xff;
+  for (i = 0; i < anum; i++) {
+    if (!strcmp (ai[i].name, "video4linux")) {
+      if (first_id == 0)
+        first_id = ai[i].base_id;
+
+      /* hmm... */
+      if (first_id != 0 && ai[i].base_id == first_id + min)
+        id = ai[i].base_id;
+    }
+  }
+  XvFreeAdaptorInfo (ai);
+
+  if (id == 0) {
+    GST_WARNING ("Did not find XvPortID for device - no overlay");
+    XCloseDisplay (dpy);
+    return;
+  }
+
+  v4lxv = g_new0 (GstV4lXv, 1);
+  v4lxv->dpy = dpy;
+  v4lxv->port = id;
+  v4lxv->mutex = g_mutex_new ();
+  v4lxv->idle_id = 0;
+  v4lelement->xv = v4lxv;
+
+  if (v4lelement->xwindow_id) {
+    gst_v4l_xoverlay_set_xwindow_id (GST_X_OVERLAY (v4lelement),
+        v4lelement->xwindow_id);
+  }
+}
+
+static void
+gst_v4l_xoverlay_close (GstV4lElement * v4lelement)
+{
+  GstV4lXv *v4lxv = v4lelement->xv;
+
+  if (!v4lelement->xv)
+    return;
+
+  if (v4lelement->xwindow_id) {
+    gst_v4l_xoverlay_set_xwindow_id (GST_X_OVERLAY (v4lelement), 0);
+  }
+
+  XCloseDisplay (v4lxv->dpy);
+  g_mutex_free (v4lxv->mutex);
+  if (v4lxv->idle_id)
+    g_source_remove (v4lxv->idle_id);
+  g_free (v4lxv);
+  v4lelement->xv = NULL;
+}
+
+void
+gst_v4l_xoverlay_start (GstV4lElement * v4lelement)
+{
+  if (v4lelement->xwindow_id) {
+    gst_v4l_xoverlay_open (v4lelement);
+  }
+}
+
+void
+gst_v4l_xoverlay_stop (GstV4lElement * v4lelement)
+{
+  gst_v4l_xoverlay_close (v4lelement);
+}
+
+static gboolean
+idle_refresh (gpointer data)
+{
+  GstV4lElement *v4lelement = GST_V4LELEMENT (data);
+  GstV4lXv *v4lxv = v4lelement->xv;
+  XWindowAttributes attr;
+
+  if (v4lxv) {
+    g_mutex_lock (v4lxv->mutex);
+
+    XGetWindowAttributes (v4lxv->dpy, v4lelement->xwindow_id, &attr);
+    XvPutVideo (v4lxv->dpy, v4lxv->port, v4lelement->xwindow_id,
+        DefaultGC (v4lxv->dpy, DefaultScreen (v4lxv->dpy)),
+        0, 0, attr.width, attr.height, 0, 0, attr.width, attr.height);
+
+    v4lxv->idle_id = 0;
+    g_mutex_unlock (v4lxv->mutex);
+  }
+
+  /* once */
+  return FALSE;
+}
+
+static void
+gst_v4l_xoverlay_set_xwindow_id (GstXOverlay * overlay, XID xwindow_id)
+{
+  GstV4lElement *v4lelement = GST_V4LELEMENT (overlay);
+  GstV4lXv *v4lxv;
+  XWindowAttributes attr;
+  gboolean change = (v4lelement->xwindow_id != xwindow_id);
+
+  GST_LOG_OBJECT (v4lelement, "Changing port to %lx", xwindow_id);
+
+  if (!v4lelement->xv && GST_V4L_IS_OPEN (v4lelement))
+    gst_v4l_xoverlay_open (v4lelement);
+
+  v4lxv = v4lelement->xv;
+
+  if (v4lxv)
+    g_mutex_lock (v4lxv->mutex);
+
+  if (change) {
+    if (v4lelement->xwindow_id && v4lxv) {
+      GST_DEBUG_OBJECT (v4lelement,
+          "Disabling port %lx", v4lelement->xwindow_id);
+
+      XvSelectPortNotify (v4lxv->dpy, v4lxv->port, 0);
+      XvSelectVideoNotify (v4lxv->dpy, v4lelement->xwindow_id, 0);
+      XvStopVideo (v4lxv->dpy, v4lxv->port, v4lelement->xwindow_id);
+    }
+
+    v4lelement->xwindow_id = xwindow_id;
+  }
+
+  if (!v4lxv || xwindow_id == 0) {
+    if (v4lxv)
+      g_mutex_unlock (v4lxv->mutex);
+    return;
+  }
+
+  if (change) {
+    GST_DEBUG_OBJECT (v4lelement, "Enabling port %lx", xwindow_id);
+
+    /* draw */
+    XvSelectPortNotify (v4lxv->dpy, v4lxv->port, 1);
+    XvSelectVideoNotify (v4lxv->dpy, v4lelement->xwindow_id, 1);
+  }
+
+  XGetWindowAttributes (v4lxv->dpy, v4lelement->xwindow_id, &attr);
+  XvPutVideo (v4lxv->dpy, v4lxv->port, v4lelement->xwindow_id,
+      DefaultGC (v4lxv->dpy, DefaultScreen (v4lxv->dpy)),
+      0, 0, attr.width, attr.height, 0, 0, attr.width, attr.height);
+
+  if (v4lxv->idle_id)
+    g_source_remove (v4lxv->idle_id);
+  v4lxv->idle_id = g_idle_add (idle_refresh, v4lelement);
+  g_mutex_unlock (v4lxv->mutex);
+}