Some interface implementations for video4linux/video4linux2 plugins: a Tuner interface, with which one can select inp...

Original commit message from CVS:
Some interface implementations for video4linux/video4linux2 plugins:
* a Tuner interface, with which one can select inputs and stations. Audio
work is underway here, but unfinished.
* A Xoverlay interface with which one can do simple overlay. Similar to
the API of the v4l/Xv XFree86 extension. Widget implementation for
GTK-2.0 coming up in the sandbox.
* Colorbalance - for adapting colors (brightness, contrast, etc.) - pretty
basic and maybe somewhat overdesigned. But it'll do for now.

Apart from these interfaces, there's also a loadable library 'xwindowlistener'
that listenes to X for the movement of a window and the overlap of other
windows. This is partly copied from xawtv (and thus partly GPL :(), but it's
needed for the xoverlay interface implementation in the v4l/v4l2 elements.

Lastly, some small changes to remove redundant properties from the v4l/v4l2
elements since these can be done much simpler. Comments appreciated!

1 files changed, 128 insertions, 0 deletions

diff --git a/sys/v4l2/gstv4l2xoverlay.c b/sys/v4l2/gstv4l2xoverlay.c
new file mode 100644
index 00000000..10c5f77b
--- /dev/null
+++ b/sys/v4l2/gstv4l2xoverlay.c
@@ -0,0 +1,128 @@
+/* GStreamer X-based overlay interface implementation
+ * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ *
+ * gstv4l2xoverlay.c: X-based overlay interface implementation for V4L2
+ *
+ * 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 <gst/gst.h>
+#include <gst/xoverlay/xoverlay.h>
+#include <gst/xwindowlistener/xwindowlistener.h>
+
+#include "gstv4l2xoverlay.h"
+#include "gstv4l2element.h"
+#include "v4l2_calls.h"
+
+static void	gst_v4l2_xoverlay_set_xwindow_id (GstXOverlay *overlay,
+						  XID          xwindow_id);
+
+void
+gst_v4l2_xoverlay_interface_init (GstXOverlayClass *klass)
+{
+  /* default virtual functions */
+  klass->set_xwindow_id = gst_v4l2_xoverlay_set_xwindow_id;
+}
+
+GstXWindowListener *
+gst_v4l2_xoverlay_new (GstV4l2Element *v4l2element)
+{
+  GstXWindowListener *xwin =
+	gst_x_window_listener_new (NULL,
+				   (MapWindowFunc) gst_v4l2_enable_overlay,
+				   (SetWindowFunc) gst_v4l2_set_window,
+				   (gpointer) v4l2element);
+
+  v4l2element->overlay = xwin;
+  v4l2element->xwindow_id = 0;
+
+  return xwin;
+}
+
+void
+gst_v4l2_xoverlay_free (GstV4l2Element *v4l2element)
+{
+  gst_v4l2_xoverlay_close (v4l2element);
+  g_object_unref (G_OBJECT (v4l2element->overlay));
+  v4l2element->overlay = NULL;
+}
+
+void
+gst_v4l2_xoverlay_open (GstV4l2Element *v4l2element)
+{
+  GstXWindowListener *xwin = v4l2element->overlay;
+
+  if (xwin) {
+    xwin->display_name = g_strdup (v4l2element->display);
+
+    if (v4l2element->xwindow_id != 0 &&
+        xwin->display_name &&
+        xwin->display_name[0] == ':') {
+      gst_x_window_listener_set_xid (xwin, v4l2element->xwindow_id);
+    }
+  }
+}
+
+void
+gst_v4l2_xoverlay_close (GstV4l2Element *v4l2element)
+{
+  GstXWindowListener *xwin = v4l2element->overlay;
+
+  if (xwin != NULL) {
+    if (v4l2element->xwindow_id != 0 &&
+        xwin->display_name &&
+        xwin->display_name[0] == ':') {
+      gst_x_window_listener_set_xid (xwin, 0);
+    }
+
+    g_free (xwin->display_name);
+    xwin->display_name = NULL;
+  }
+}
+
+static void
+gst_v4l2_xoverlay_set_xwindow_id (GstXOverlay *overlay,
+				  XID          xwindow_id)
+{
+  GstV4l2Element *v4l2element = GST_V4L2ELEMENT (overlay);
+  GstXWindowListener *xwin = v4l2element->overlay;
+
+  if (v4l2element->xwindow_id == xwindow_id) {
+    return;
+  }
+
+  if (gst_element_get_state (GST_ELEMENT (v4l2element)) != GST_STATE_NULL &&
+      v4l2element->xwindow_id != 0 &&
+      xwin != NULL &&
+      xwin->display_name &&
+      xwin->display_name[0] == ':') {
+    gst_x_window_listener_set_xid (xwin, 0);
+  }
+
+  v4l2element->xwindow_id = xwindow_id;
+
+  if (gst_element_get_state (GST_ELEMENT (v4l2element)) != GST_STATE_NULL &&
+      v4l2element->xwindow_id != 0 &&
+      xwin != NULL &&
+      xwin->display_name &&
+      xwin->display_name[0] == ':') {
+    gst_x_window_listener_set_xid (xwin, v4l2element->xwindow_id);
+  }
+}