[gegl] workshop: add vhsfix

[Øyvind Kolås <ok src gnome org>]

commit 2eada2ff877c501ef5924af7fe4ebd2b705e94ef
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Mar 25 01:24:25 2016 +0100

    workshop: add vhsfix

 operations/workshop/Makefile.am |    1 +
 operations/workshop/vhsfix.c    |  263 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 264 insertions(+), 0 deletions(-)
---
diff --git a/operations/workshop/Makefile.am b/operations/workshop/Makefile.am
index 7e528b2..1dff8a5 100644
--- a/operations/workshop/Makefile.am
+++ b/operations/workshop/Makefile.am
@@ -26,4 +26,5 @@ op_LTLIBRARIES =    \
        rawbayer-load.la \
        rgb-clip.la \
        unpremul.la \
+    vhsfix.la \
        gradient-map.la
diff --git a/operations/workshop/vhsfix.c b/operations/workshop/vhsfix.c
new file mode 100644
index 0000000..aae99c2
--- /dev/null
+++ b/operations/workshop/vhsfix.c
@@ -0,0 +1,263 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL 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 3 of the License, or (at your option) any later version.
+ *
+ * GEGL 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 GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2016 Øyvind Kolås <pippin gimp org>
+ */
+
+//#include <glib/gi18n-lib.h>
+#define _(a) (a)
+
+#ifdef GEGL_PROPERTIES
+
+property_double (dampness, _("Dampness"), 0.95)
+    description (_("The value represents the contribution of the past to the new frame."))
+    value_range (0.0, 1.0)
+
+#else
+
+#define GEGL_OP_FILTER
+#define GEGL_OP_NO_SOURCE
+#define GEGL_OP_C_SOURCE vhsfix.c
+
+#include "gegl-op.h"
+
+#define TEMP_BUFS 5
+
+typedef struct
+{
+  GeglBuffer *acc[TEMP_BUFS];
+  int         uninitialized;
+} Priv;
+
+
+static void
+init (GeglProperties *o)
+{
+  Priv         *priv = (Priv*)o->user_data;
+  GeglRectangle extent = {0,0,1024,1024};
+
+  g_assert (priv == NULL);
+
+  priv = g_new0 (Priv, 1);
+  o->user_data = (void*) priv;
+
+  for (int i=0;i< TEMP_BUFS;i++)
+    priv->acc[i] = gegl_buffer_new (&extent, babl_format ("RGBA float"));
+  priv->uninitialized = 1;
+}
+
+static void prepare (GeglOperation *operation)
+{
+  gegl_operation_set_format (operation, "output", babl_format ("RGBA float"));
+}
+
+#include <math.h>
+
+#include <stdio.h>
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result,
+         gint                 level)
+{
+  GeglProperties *o;
+  Priv           *p;
+
+  o = GEGL_PROPERTIES (operation);
+  p = (Priv*)o->user_data;
+  if (p == NULL)
+    init (o);
+  p = (Priv*)o->user_data;
+
+  {
+    gint pixels = result->width * result->height;
+    gfloat *acc[TEMP_BUFS];
+    gfloat *buf;
+    gint i;
+    gfloat totdiff = 0.0;
+    int x, y;
+    int last_set[8192]={0,};
+    for (i = 0; i < TEMP_BUFS; i++)
+      acc[i] = g_new (gfloat, pixels * 4);
+    buf = g_new (gfloat, pixels * 4);
+
+    if (p->uninitialized)
+    {
+      gegl_buffer_get (input, result, 1.0, babl_format ("RGBA float"), buf, GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+      for (i = 0; i<TEMP_BUFS; i++)
+      {
+        gegl_buffer_set (p->acc[i], result, 0, babl_format ("RGBA float"), buf, GEGL_AUTO_ROWSTRIDE);
+        gegl_buffer_get (input, result, 1.0, babl_format ("RGBA float"), acc[i], GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+      }
+      p->uninitialized = 0;
+    }
+    else
+    {
+
+    for (i = TEMP_BUFS-1; i > 0; i--)
+    {
+      gegl_buffer_get (p->acc[i-1], result, 1.0, babl_format ("RGBA float"), acc[i], GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+      gegl_buffer_set (p->acc[i], result, 0, babl_format ("RGBA float"), acc[i], GEGL_AUTO_ROWSTRIDE);
+    }
+
+    gegl_buffer_get (input, result, 1.0, babl_format ("RGBA float"), acc[0], GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+    gegl_buffer_get (input, result, 1.0, babl_format ("RGBA float"), buf, GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+    gegl_buffer_set (p->acc[0], result, 0, babl_format ("RGBA float"), acc[0], GEGL_AUTO_ROWSTRIDE);
+    }
+
+    for (i=0;i<pixels;i++)
+      {
+        gint c;
+        for (c=0;c<4;c++)
+        {
+          int t;
+          float avg[4] = {0,0,0,0};
+          float avg2[4] = {0,0,0,0};
+
+          for (t = 2; t < TEMP_BUFS; t++)
+            avg[c] += acc[t][i*4+c];
+          avg[c] /= (TEMP_BUFS);
+
+          for (t = 1; t < TEMP_BUFS-2; t++)
+            avg2[c] += acc[t][i*4+c];
+          avg2[c] /= (TEMP_BUFS - 1 - 2);
+
+#define ACC(a) acc[a][i*4+c]
+          if (fabs (ACC(0) - avg[c]) > 0.05)
+            ACC(0) = avg2[c];
+        }
+      }
+
+    i = 0;
+
+    for (y = result->y; y < result->y + result->height-1; y++)
+      for (x = result->x; x < result->x + result->width; x++)
+      {
+        int c;
+        float diff = 0;
+        for (c = 0; c < 3; c++)
+          if (acc[0][i * 4 + c] != buf[i * 4 + c])
+          {
+            diff+=fabs(acc[0][i * 4 + c] - buf[i * 4 + c]) *
+                  fabs(acc[0][i * 4 + c] - buf[i * 4 + c]);
+          }
+        diff = sqrtf (diff);
+        if (diff > 0.02f)
+        {
+          if (last_set[x] < 1) /* permit up to two pixels wide artifacts */
+          {
+            if (y > 1)
+            for (c = 0; c < 4; c++)
+              buf[i * 4 + c] = acc[0][i * 4 + c] * 0.2 + buf[(i-result->width) * 4 + c] * 0.4 + 
buf[(i-result->width) * 4 + c] * 0.4;
+            else
+            for (c = 0; c < 4; c++)
+              buf[i * 4 + c] = acc[0][i * 4 + c];
+            last_set[x]++;
+          }
+          else if (last_set[x] > 1)
+          {
+            if (y > 1)
+            for (c = 0; c < 4; c++)
+              buf[i * 4 + c] = acc[0][i * 4 + c] * 0.2 + buf[(i-result->width) * 4 + c] * 0.4 + 
buf[(i-result->width) * 4 + c] * 0.4;
+
+            else
+            for (c = 0; c < 4; c++)
+              buf[i * 4 + c] = acc[0][i * 4 + c];
+            last_set[x] = 0;
+          }
+        }
+        else
+        {
+          last_set[x]++;
+        }
+        i++;
+      }
+
+    /* if reset, refetch buf .. and set scene-change flag */
+
+    totdiff = 0;
+    i = 0;
+    for (y = result->y; y < result->y + result->height; y++)
+      for (x = result->x; x < result->x + result->width; x++)
+      {
+        int c;
+        float diff = 0;
+        for (c = 0; c < 3; c++)
+          diff+=fabs(acc[0][i * 4 + c] - acc[1][i * 4 + c]) *
+                fabs(acc[0][i * 4 + c] - acc[1][i * 4 + c]);
+        if (diff != 0.0)
+          totdiff += sqrtf (diff);
+        i++;
+      }
+    totdiff /= i;
+
+    if (totdiff > 0.04)
+    {
+      gegl_buffer_get (input, result, 1.0, babl_format ("RGBA float"), buf, GEGL_AUTO_ROWSTRIDE, 
GEGL_ABYSS_NONE);
+      p->uninitialized = 1;
+    }
+
+    gegl_buffer_set (output, result, 0, babl_format ("RGBA float"), buf, GEGL_AUTO_ROWSTRIDE);
+    for (i = 0; i < TEMP_BUFS; i++)
+      g_free (acc[i]);
+    g_free (buf);
+  }
+
+  return  TRUE;
+}
+
+static void
+finalize (GObject *object)
+{
+  GeglProperties *o = GEGL_PROPERTIES (object);
+
+  if (o->user_data)
+    {
+      Priv *p = (Priv*)o->user_data;
+
+      g_object_unref (p->acc);
+
+      g_free (o->user_data);
+      o->user_data = NULL;
+    }
+  G_OBJECT_CLASS (gegl_op_parent_class)->finalize (object);
+}
+
+
+static void
+gegl_op_class_init (GeglOpClass *klass)
+{
+  GeglOperationClass       *operation_class;
+  GeglOperationFilterClass *filter_class;
+
+  G_OBJECT_CLASS (klass)->finalize = finalize;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);
+
+  filter_class->process = process;
+  operation_class->prepare = prepare;
+
+  gegl_operation_class_set_keys (operation_class,
+    "name",        "gegl:vhsfix",
+    "title",       _("vhs glitch fixer"),
+    "categories" , "video",
+    "description", _("fixes vhs digitization glithces"),
+    NULL);
+}
+
+#endif