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, 151 insertions, 0 deletions

diff --git a/sys/v4l2/gstv4l2colorbalance.c b/sys/v4l2/gstv4l2colorbalance.c
new file mode 100644
index 00000000..d0c1dcf8
--- /dev/null
+++ b/sys/v4l2/gstv4l2colorbalance.c
@@ -0,0 +1,151 @@
+/* GStreamer Color Balance interface implementation
+ * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ *
+ * gstv4l2colorbalance.c: color balance 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 "gstv4l2colorbalance.h"
+#include "gstv4l2element.h"
+
+static void
+gst_v4l2_color_balance_channel_class_init(GstV4l2ColorBalanceChannelClass *klass);
+static void
+gst_v4l2_color_balance_channel_init	(GstV4l2ColorBalanceChannel *channel);
+
+static const GList *
+gst_v4l2_color_balance_list_channels	(GstColorBalance        *balance);
+static void
+gst_v4l2_color_balance_set_value	(GstColorBalance        *balance,
+					 GstColorBalanceChannel *channel,
+					 gint                    value);
+static gint
+gst_v4l2_color_balance_get_value	(GstColorBalance        *balance,
+					 GstColorBalanceChannel *channel);
+
+static GstColorBalanceChannelClass *parent_class = NULL;
+
+GType
+gst_v4l2_color_balance_channel_get_type (void)
+{
+  static GType gst_v4l2_color_balance_channel_type = 0;
+
+  if (!gst_v4l2_color_balance_channel_type) {
+    static const GTypeInfo v4l2_tuner_channel_info = {
+      sizeof (GstV4l2ColorBalanceChannelClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) gst_v4l2_color_balance_channel_class_init,
+      NULL,
+      NULL,
+      sizeof (GstV4l2ColorBalanceChannel),
+      0,
+      (GInstanceInitFunc) gst_v4l2_color_balance_channel_init,
+      NULL
+    };
+
+    gst_v4l2_color_balance_channel_type =
+	g_type_register_static (GST_TYPE_COLOR_BALANCE_CHANNEL,
+				"GstV4l2ColorBalanceChannel",
+				&v4l2_tuner_channel_info, 0);
+  }
+
+  return gst_v4l2_color_balance_channel_type;
+}
+
+static void
+gst_v4l2_color_balance_channel_class_init (GstV4l2ColorBalanceChannelClass *klass)
+{
+  parent_class = g_type_class_ref (GST_TYPE_COLOR_BALANCE_CHANNEL);
+}
+
+static void
+gst_v4l2_color_balance_channel_init (GstV4l2ColorBalanceChannel *channel)
+{
+  channel->index = 0;
+}
+
+void
+gst_v4l2_color_balance_interface_init (GstColorBalanceClass *klass)
+{
+  /* default virtual functions */
+  klass->list_channels = gst_v4l2_color_balance_list_channels;
+  klass->set_value = gst_v4l2_color_balance_set_value;
+  klass->get_value = gst_v4l2_color_balance_get_value;
+}
+
+static gboolean
+gst_v4l2_color_balance_contains_channel (GstV4l2Element             *v4l2element,
+					 GstV4l2ColorBalanceChannel *v4l2channel)
+{
+  const GList *item;
+
+  for (item = v4l2element->colors; item != NULL; item = item->next)
+    if (item->data == v4l2channel)
+      return TRUE;
+
+  return FALSE;
+}
+
+static const GList *
+gst_v4l2_color_balance_list_channels (GstColorBalance *balance)
+{
+  return GST_V4L2ELEMENT (balance)->colors;
+}
+
+static void
+gst_v4l2_color_balance_set_value (GstColorBalance        *balance,
+				  GstColorBalanceChannel *channel,
+				  gint                    value)
+{
+  GstV4l2Element *v4l2element = GST_V4L2ELEMENT (balance);
+  GstV4l2ColorBalanceChannel *v4l2channel =
+	GST_V4L2_COLOR_BALANCE_CHANNEL (channel);
+
+  /* assert that we're opened and that we're using a known item */
+  g_return_if_fail (GST_V4L2_IS_OPEN (v4l2element));
+  g_return_if_fail (gst_v4l2_color_balance_contains_channel (v4l2element,
+							     v4l2channel));
+
+  gst_v4l2_set_attribute (v4l2element, v4l2channel->index, value);
+}
+
+static gint
+gst_v4l2_color_balance_get_value (GstColorBalance        *balance,
+				  GstColorBalanceChannel *channel)
+{
+  GstV4l2Element *v4l2element = GST_V4L2ELEMENT (balance);
+  GstV4l2ColorBalanceChannel *v4l2channel =
+	GST_V4L2_COLOR_BALANCE_CHANNEL (channel);
+  gint value;
+
+  /* assert that we're opened and that we're using a known item */
+  g_return_val_if_fail (GST_V4L2_IS_OPEN (v4l2element), 0);
+  g_return_val_if_fail (gst_v4l2_color_balance_contains_channel (v4l2element,
+							         v4l2channel),
+			0);
+
+  if (!gst_v4l2_get_attribute (v4l2element, v4l2channel->index, &value))
+    return 0;
+
+  return value;
+}