1 files changed, 55 insertions, 0 deletions
diff --git a/v4l2-apps/libv4l/libv4lconvert/processing/gamma.c b/v4l2-apps/libv4l/libv4lconvert/processing/gamma.c
new file mode 100644
index 000000000..7695abcb7
--- /dev/null
+++ b/v4l2-apps/libv4l/libv4lconvert/processing/gamma.c
@@ -0,0 +1,55 @@
+/*
+#             (C) 2008-2009 Hans de Goede <hdegoede@redhat.com>
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# This program 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#include <math.h>
+#include "libv4lprocessing.h"
+#include "libv4lprocessing-priv.h"
+
+#define CLIP(color) (unsigned char)(((color)>0xff)?0xff:(((color)<0)?0:(color)))
+
+static int gamma_active(struct v4lprocessing_data *data) {
+  return v4lcontrol_get_ctrl(data->control, V4LCONTROL_GAMMA) != 1000;
+}
+
+static int gamma_calculate_lookup_tables(
+  struct v4lprocessing_data *data,
+  unsigned char *buf, const struct v4l2_format *fmt)
+{
+  int i, x, gamma;
+
+  gamma = v4lcontrol_get_ctrl(data->control, V4LCONTROL_GAMMA);
+
+  if (gamma != data->last_gamma) {
+    for (i = 0; i < 256; i++) {
+      x = powf(i / 255.0, 1000.0 / gamma) * 255;
+      data->gamma_table[i] = CLIP(x);
+    }
+    data->last_gamma = gamma;
+  }
+
+  for (i = 0; i < 256; i++) {
+    data->comp1[i] = data->gamma_table[data->comp1[i]];
+    data->green[i] = data->gamma_table[data->green[i]];
+    data->comp2[i] = data->gamma_table[data->comp2[i]];
+  }
+
+  return 1;
+}
+
+struct v4lprocessing_filter gamma_filter = {
+  gamma_active, gamma_calculate_lookup_tables };