libv4l: rewrite video processing code

From: Hans de Goede <hdegoede@redhat.com>

Rewrite video processing code to make it easier to add more video filters
(and with little extra processing cost). As part of this the normalize
filter has been removed as it wasn't functioning satisfactory anyways

Priority: normal

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/v4l2-apps/libv4l/libv4lconvert/processing/whitebalance.c b/v4l2-apps/libv4l/libv4lconvert/processing/whitebalance.c
new file mode 100644
index 000000000..f5bfd961c
--- /dev/null
+++ b/v4l2-apps/libv4l/libv4lconvert/processing/whitebalance.c
@@ -0,0 +1,143 @@
+/*
+#             (C) 2008-2009 Elmar Kleijn <elmar_kleijn@hotmail.com>
+#             (C) 2008-2009 Sjoerd Piepenbrink <need4weed@gmail.com>
+#             (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 <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <syscall.h>
+#include <unistd.h>
+#include "libv4lprocessing.h"
+#include "libv4lprocessing-priv.h"
+#include "../libv4lconvert-priv.h" /* for PIX_FMT defines */
+
+#define CLIP(color) (unsigned char)(((color)>0xff)?0xff:(((color)<0)?0:(color)))
+
+static int whitebalance_active(struct v4lprocessing_data *data) {
+  return v4lcontrol_get_ctrl(data->control, V4LCONTROL_WHITEBALANCE);
+}
+
+static int whitebalance_calculate_lookup_tables_bayer(
+  struct v4lprocessing_data *data, unsigned char *buf,
+  const struct v4l2_format *fmt, int starts_with_green)
+{
+  int x, y, a1 = 0, a2 = 0, b1 = 0, b2 = 0;
+  int green_avg, comp1_avg, comp2_avg, avg_avg;
+
+  for (y = 0; y < fmt->fmt.pix.height; y += 2) {
+    for (x = 0; x < fmt->fmt.pix.width; x += 2) {
+      a1 += *buf++;
+      a2 += *buf++;
+    }
+    buf += fmt->fmt.pix.bytesperline - fmt->fmt.pix.width;
+    for (x = 0; x < fmt->fmt.pix.width; x += 2) {
+      b1 += *buf++;
+      b2 += *buf++;
+    }
+    buf += fmt->fmt.pix.bytesperline - fmt->fmt.pix.width;
+  }
+
+  if (starts_with_green) {
+    green_avg = (a1 + b2) / 512;
+    comp1_avg = a2 / 256;
+    comp2_avg = b1 / 256;
+  } else {
+    green_avg = (a2 + b1) / 512;
+    comp1_avg = a1 / 256;
+    comp2_avg = b2 / 256;
+  }
+
+  x = fmt->fmt.pix.width * fmt->fmt.pix.height / 64;
+  if (abs(green_avg - comp1_avg) < x &&
+      abs(green_avg - comp2_avg) < x &&
+      abs(comp1_avg - comp2_avg) < x)
+    return 0;
+
+  avg_avg = (green_avg + comp1_avg + comp2_avg) / 3;
+
+  for (x = 0; x < 256; x++) {
+    data->comp1[x] = CLIP(data->comp1[x] * avg_avg / comp1_avg);
+    data->green[x] = CLIP(data->green[x] * avg_avg / green_avg);
+    data->comp2[x] = CLIP(data->comp2[x] * avg_avg / comp2_avg);
+  }
+
+  return 1;
+}
+
+static int whitebalance_calculate_lookup_tables_rgb(
+  struct v4lprocessing_data *data, unsigned char *buf,
+  const struct v4l2_format *fmt)
+{
+  int x, y, green_avg = 0, comp1_avg = 0, comp2_avg = 0, avg_avg;
+
+  for (y = 0; y < fmt->fmt.pix.height; y++) {
+    for (x = 0; x < fmt->fmt.pix.width; x++) {
+      comp1_avg += *buf++;
+      green_avg += *buf++;
+      comp2_avg += *buf++;
+    }
+    buf += fmt->fmt.pix.bytesperline - fmt->fmt.pix.width * 3;
+  }
+
+  x = fmt->fmt.pix.width * fmt->fmt.pix.height * 4;
+  if (abs(green_avg - comp1_avg) < x &&
+      abs(green_avg - comp2_avg) < x &&
+      abs(comp1_avg - comp2_avg) < x)
+    return 0;
+
+  /* scale to avoid integer overflows */
+  green_avg /= 256;
+  comp1_avg /= 256;
+  comp2_avg /= 256;
+  avg_avg = (green_avg + comp1_avg + comp2_avg) / 3;
+
+  for (x = 0; x < 256; x++) {
+    data->comp1[x] = CLIP(data->comp1[x] * avg_avg / comp1_avg);
+    data->green[x] = CLIP(data->green[x] * avg_avg / green_avg);
+    data->comp2[x] = CLIP(data->comp2[x] * avg_avg / comp2_avg);
+  }
+
+  return 1;
+}
+
+
+static int whitebalance_calculate_lookup_tables(
+  struct v4lprocessing_data *data,
+  unsigned char *buf, const struct v4l2_format *fmt)
+{
+  switch (fmt->fmt.pix.pixelformat) {
+    case V4L2_PIX_FMT_SGBRG8:
+    case V4L2_PIX_FMT_SGRBG8: /* Bayer patterns starting with green */
+      return whitebalance_calculate_lookup_tables_bayer(data, buf, fmt, 1);
+
+    case V4L2_PIX_FMT_SBGGR8:
+    case V4L2_PIX_FMT_SRGGB8: /* Bayer patterns *NOT* starting with green */
+      return whitebalance_calculate_lookup_tables_bayer(data, buf, fmt, 0);
+
+    case V4L2_PIX_FMT_RGB24:
+    case V4L2_PIX_FMT_BGR24:
+      return whitebalance_calculate_lookup_tables_rgb(data, buf, fmt);
+  }
+
+  return 0; /* Should never happen */
+}
+
+struct v4lprocessing_filter whitebalance_filter = {
+  whitebalance_active, whitebalance_calculate_lookup_tables };