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authorMauro Carvalho Chehab <mchehab@redhat.com>2009-08-30 18:56:14 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-08-30 18:56:14 -0300
commit502293205239f8ec860b4c33187cd7a3fc0f421c (patch)
tree3859aab46057cb3726731ca0ef65cd45c9e73660 /v4l2-apps/libv4l/libv4lconvert/processing/gamma.c
parent71911bc952f2394dede17c5713de0b0dfcb04fae (diff)
parent52ef68ff244a5cd4707558c9aa803ecb9c1342dc (diff)
downloadmediapointer-dvb-s2-502293205239f8ec860b4c33187cd7a3fc0f421c.tar.gz
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merge: http://kernellabs.com/hg/~mkrufky/tda18271
From: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'v4l2-apps/libv4l/libv4lconvert/processing/gamma.c')
-rw-r--r--v4l2-apps/libv4l/libv4lconvert/processing/gamma.c57
1 files changed, 57 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..fcb5bb0cf
--- /dev/null
+++ b/v4l2-apps/libv4l/libv4lconvert/processing/gamma.c
@@ -0,0 +1,57 @@
+/*
+# (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) {
+ int gamma = v4lcontrol_get_ctrl(data->control, V4LCONTROL_GAMMA);
+
+ return gamma && 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 };