Adding upstream version 2.10.36.upstream/2.10.36

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 782 insertions, 0 deletions

diff --git a/plug-ins/common/hot.c b/plug-ins/common/hot.c
new file mode 100644
index 0000000..8ed215e
--- /dev/null
+++ b/plug-ins/common/hot.c
@@ -0,0 +1,782 @@
+/*
+ * GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+ * hot.c - Scan an image for pixels with RGB values that will give
+ *      "unsafe" values of chrominance signal or composite signal
+ *      amplitude when encoded into an NTSC or PAL color signal.
+ *      (This happens for certain high-intensity high-saturation colors
+ *      that are rare in real scenes, but can easily be present
+ *      in synthetic images.)
+ *
+ *      Such pixels can be flagged so the user may then choose other
+ *      colors.  Or, the offending pixels can be made "safe"
+ *      in a manner that preserves hue.
+ *
+ *      There are two reasonable ways to make a pixel "safe":
+ *      We can reduce its intensity (luminance) while leaving
+ *      hue and saturation the same.  Or, we can reduce saturation
+ *      while leaving hue and luminance the same.  A #define selects
+ *      which strategy to use.
+ *
+ * Note to the user: You must add your own read_pixel() and write_pixel()
+ *      routines.  You may have to modify pix_decode() and pix_encode().
+ *      MAXPIX, WID, and HGT are likely to need modification.
+ */
+
+/*
+ * Originally written as "ikNTSC.c" by Alan Wm Paeth,
+ *      University of Waterloo, August, 1985
+ * Updated by Dave Martindale, Imax Systems Corp., December 1990
+ */
+
+/*
+ * Compile time options:
+ *
+ *
+ * CHROMA_LIM is the limit (in IRE units) of the overall
+ *      chrominance amplitude; it should be 50 or perhaps
+ *      very slightly higher.
+ *
+ * COMPOS_LIM is the maximum amplitude (in IRE units) allowed for
+ *      the composite signal.  A value of 100 is the maximum
+ *      monochrome white, and is always safe.  120 is the absolute
+ *      limit for NTSC broadcasting, since the transmitter's carrier
+ *      goes to zero with 120 IRE input signal.  Generally, 110
+ *      is a good compromise - it allows somewhat brighter colors
+ *      than 100, while staying safely away from the hard limit.
+ */
+
+#include "config.h"
+
+#include <string.h>
+
+#include <libgimp/gimp.h>
+#include <libgimp/gimpui.h>
+
+#include "libgimp/stdplugins-intl.h"
+
+
+#define PLUG_IN_PROC   "plug-in-hot"
+#define PLUG_IN_BINARY "hot"
+#define PLUG_IN_ROLE   "gimp-hot"
+
+
+typedef struct
+{
+  gint32 image;
+  gint32 drawable;
+  gint32 mode;
+  gint32 action;
+  gint32 new_layerp;
+} piArgs;
+
+typedef enum
+{
+  ACT_LREDUX,
+  ACT_SREDUX,
+  ACT_FLAG
+} hotAction;
+
+typedef enum
+{
+  MODE_NTSC,
+  MODE_PAL
+} hotModes;
+
+#define CHROMA_LIM      50.0            /* chroma amplitude limit */
+#define COMPOS_LIM      110.0           /* max IRE amplitude */
+
+/*
+ * RGB to YIQ encoding matrix.
+ */
+
+struct
+{
+  gdouble pedestal;
+  gdouble gamma;
+  gdouble code[3][3];
+} static mode[2] = {
+  {
+    7.5,
+    2.2,
+    {
+      { 0.2989,  0.5866,  0.1144 },
+      { 0.5959, -0.2741, -0.3218 },
+      { 0.2113, -0.5227,  0.3113 }
+    }
+  },
+  {
+    0.0,
+    2.8,
+    {
+      { 0.2989,  0.5866,  0.1144 },
+      { -0.1473, -0.2891,  0.4364 },
+      { 0.6149, -0.5145, -0.1004 }
+    }
+  }
+};
+
+
+#define SCALE   8192            /* scale factor: do floats with int math */
+#define MAXPIX   255            /* white value */
+
+static gint     tab[3][3][MAXPIX+1]; /* multiply lookup table */
+static gdouble  chroma_lim;          /* chroma limit */
+static gdouble  compos_lim;          /* composite amplitude limit */
+static glong    ichroma_lim2;        /* chroma limit squared (scaled integer) */
+static gint     icompos_lim;         /* composite amplitude limit (scaled integer) */
+
+static void       query         (void);
+static void       run           (const gchar      *name,
+                                 gint              nparam,
+                                 const GimpParam  *param,
+                                 gint             *nretvals,
+                                 GimpParam       **retvals);
+
+static gboolean   pluginCore    (piArgs           *argp);
+static gboolean   plugin_dialog (piArgs           *argp);
+static gboolean   hotp          (guint8            r,
+                                 guint8            g,
+                                 guint8            b);
+static void       build_tab     (gint              m);
+
+/*
+ * gc: apply the gamma correction specified for this video standard.
+ * inv_gc: inverse function of gc.
+ *
+ * These are generally just a call to pow(), but be careful!
+ * Future standards may use more complex functions.
+ * (e.g. SMPTE 240M's "electro-optic transfer characteristic").
+ */
+#define gc(x,m)     pow(x, 1.0 / mode[m].gamma)
+#define inv_gc(x,m) pow(x,       mode[m].gamma)
+
+/*
+ * pix_decode: decode an integer pixel value into a floating-point
+ *      intensity in the range [0, 1].
+ *
+ * pix_encode: encode a floating-point intensity into an integer
+ *      pixel value.
+ *
+ * The code given here assumes simple linear encoding; you must change
+ * these routines if you use a different pixel encoding technique.
+ */
+#define pix_decode(v)  ((double)v / (double)MAXPIX)
+#define pix_encode(v)  ((int)(v * (double)MAXPIX + 0.5))
+
+const GimpPlugInInfo PLUG_IN_INFO =
+{
+  NULL,  /* init_proc  */
+  NULL,  /* quit_proc  */
+  query, /* query_proc */
+  run,   /* run_proc   */
+};
+
+MAIN ()
+
+static void
+query (void)
+{
+  static const GimpParamDef args[] =
+  {
+    { GIMP_PDB_INT32,    "run-mode",  "The run mode { RUN-INTERACTIVE (0), RUN-NONINTERACTIVE (1) }" },
+    { GIMP_PDB_IMAGE,    "image",     "The Image" },
+    { GIMP_PDB_DRAWABLE, "drawable",  "The Drawable" },
+    { GIMP_PDB_INT32,    "mode",      "Mode { NTSC (0), PAL (1) }" },
+    { GIMP_PDB_INT32,    "action",    "The action to perform" },
+    { GIMP_PDB_INT32,    "new-layer", "Create a new layer { TRUE, FALSE }" }
+  };
+
+  gimp_install_procedure (PLUG_IN_PROC,
+                          N_("Find and fix pixels that may be unsafely bright"),
+                          "hot scans an image for pixels that will give unsave "
+                          "values of chrominance or composite signale "
+                          "amplitude when encoded into an NTSC or PAL signal.  "
+                          "Three actions can be performed on these ``hot'' "
+                          "pixels. (0) reduce luminance, (1) reduce "
+                          "saturation, or (2) Blacken.",
+                          "Eric L. Hernes, Alan Wm Paeth",
+                          "Eric L. Hernes",
+                          "1997",
+                          N_("_Hot..."),
+                          "RGB",
+                          GIMP_PLUGIN,
+                          G_N_ELEMENTS (args), 0,
+                          args, NULL);
+
+  gimp_plugin_menu_register (PLUG_IN_PROC, "<Image>/Colors/Modify");
+}
+
+static void
+run (const gchar      *name,
+     gint              nparam,
+     const GimpParam  *param,
+     gint             *nretvals,
+     GimpParam       **retvals)
+{
+  static GimpParam rvals[1];
+  piArgs           args;
+
+  *nretvals = 1;
+  *retvals  = rvals;
+
+  INIT_I18N ();
+  gegl_init (NULL, NULL);
+
+  memset (&args, 0, sizeof (args));
+  args.mode = -1;
+
+  gimp_get_data (PLUG_IN_PROC, &args);
+
+  args.image    = param[1].data.d_image;
+  args.drawable = param[2].data.d_drawable;
+
+  rvals[0].type          = GIMP_PDB_STATUS;
+  rvals[0].data.d_status = GIMP_PDB_SUCCESS;
+
+  switch (param[0].data.d_int32)
+    {
+    case GIMP_RUN_INTERACTIVE:
+      /* XXX: add code here for interactive running */
+      if (args.mode == -1)
+        {
+          args.mode       = MODE_NTSC;
+          args.action     = ACT_LREDUX;
+          args.new_layerp = 1;
+        }
+
+      if (plugin_dialog (&args))
+        {
+          if (! pluginCore (&args))
+            {
+              rvals[0].data.d_status = GIMP_PDB_EXECUTION_ERROR;
+            }
+        }
+      else
+        {
+          rvals[0].data.d_status = GIMP_PDB_CANCEL;
+        }
+
+      gimp_set_data (PLUG_IN_PROC, &args, sizeof (args));
+    break;
+
+    case GIMP_RUN_NONINTERACTIVE:
+      /* XXX: add code here for non-interactive running */
+      if (nparam != 6)
+        {
+          rvals[0].data.d_status = GIMP_PDB_CALLING_ERROR;
+          break;
+        }
+      args.mode       = param[3].data.d_int32;
+      args.action     = param[4].data.d_int32;
+      args.new_layerp = param[5].data.d_int32;
+
+      if (! pluginCore (&args))
+        {
+          rvals[0].data.d_status = GIMP_PDB_EXECUTION_ERROR;
+          break;
+        }
+    break;
+
+    case GIMP_RUN_WITH_LAST_VALS:
+      /* XXX: add code here for last-values running */
+      if (! pluginCore (&args))
+        {
+          rvals[0].data.d_status = GIMP_PDB_EXECUTION_ERROR;
+        }
+    break;
+  }
+}
+
+static gboolean
+pluginCore (piArgs *argp)
+{
+  GeglBuffer *src_buffer;
+  GeglBuffer *dest_buffer;
+  const Babl *src_format;
+  const Babl *dest_format;
+  gint        src_bpp;
+  gint        dest_bpp;
+  gboolean    success = TRUE;
+  gint        nl      = 0;
+  gint        y, i;
+  gint        Y, I, Q;
+  gint        width, height;
+  gint        sel_x1, sel_x2, sel_y1, sel_y2;
+  gint        prog_interval;
+  guchar     *src, *s, *dst, *d;
+  guchar      r, prev_r=0, new_r=0;
+  guchar      g, prev_g=0, new_g=0;
+  guchar      b, prev_b=0, new_b=0;
+  gdouble     fy, fc, t, scale;
+  gdouble     pr, pg, pb;
+  gdouble     py;
+
+  width  = gimp_drawable_width  (argp->drawable);
+  height = gimp_drawable_height (argp->drawable);
+
+  if (gimp_drawable_has_alpha (argp->drawable))
+    src_format = babl_format ("R'G'B'A u8");
+  else
+    src_format = babl_format ("R'G'B' u8");
+
+  dest_format = src_format;
+
+  if (argp->new_layerp)
+    {
+      gchar        name[40];
+      const gchar *mode_names[] =
+      {
+        "ntsc",
+        "pal",
+      };
+      const gchar *action_names[] =
+      {
+        "lum redux",
+        "sat redux",
+        "flag",
+      };
+
+      g_snprintf (name, sizeof (name), "hot mask (%s, %s)",
+                  mode_names[argp->mode],
+                  action_names[argp->action]);
+
+      nl = gimp_layer_new (argp->image, name, width, height,
+                           GIMP_RGBA_IMAGE,
+                           100,
+                           gimp_image_get_default_new_layer_mode (argp->image));
+
+      gimp_drawable_fill (nl, GIMP_FILL_TRANSPARENT);
+      gimp_image_insert_layer (argp->image, nl, -1, 0);
+
+      dest_format = babl_format ("R'G'B'A u8");
+    }
+
+  if (! gimp_drawable_mask_intersect (argp->drawable,
+                                      &sel_x1, &sel_y1, &width, &height))
+    return success;
+
+  src_bpp  = babl_format_get_bytes_per_pixel (src_format);
+  dest_bpp = babl_format_get_bytes_per_pixel (dest_format);
+
+  sel_x2 = sel_x1 + width;
+  sel_y2 = sel_y1 + height;
+
+  src = g_new (guchar, width * height * src_bpp);
+  dst = g_new (guchar, width * height * dest_bpp);
+
+  src_buffer = gimp_drawable_get_buffer (argp->drawable);
+
+  if (argp->new_layerp)
+    {
+      dest_buffer = gimp_drawable_get_buffer (nl);
+    }
+  else
+    {
+      dest_buffer = gimp_drawable_get_shadow_buffer (argp->drawable);
+    }
+
+  gegl_buffer_get (src_buffer,
+                   GEGL_RECTANGLE (sel_x1, sel_y1, width, height), 1.0,
+                   src_format, src,
+                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  s = src;
+  d = dst;
+
+  build_tab (argp->mode);
+
+  gimp_progress_init (_("Hot"));
+  prog_interval = height / 10;
+
+  for (y = sel_y1; y < sel_y2; y++)
+    {
+      gint x;
+
+      if (y % prog_interval == 0)
+        gimp_progress_update ((double) y / (double) (sel_y2 - sel_y1));
+
+      for (x = sel_x1; x < sel_x2; x++)
+        {
+          if (hotp (r = *(s + 0), g = *(s + 1), b = *(s + 2)))
+            {
+              if (argp->action == ACT_FLAG)
+                {
+                  for (i = 0; i < 3; i++)
+                    *d++ = 0;
+                  s += 3;
+                  if (src_bpp == 4)
+                    *d++ = *s++;
+                  else if (argp->new_layerp)
+                    *d++ = 255;
+                }
+              else
+                {
+                  /*
+                   * Optimization: cache the last-computed hot pixel.
+                   */
+                  if (r == prev_r && g == prev_g && b == prev_b)
+                    {
+                      *d++ = new_r;
+                      *d++ = new_g;
+                      *d++ = new_b;
+                      s += 3;
+                      if (src_bpp == 4)
+                        *d++ = *s++;
+                      else if (argp->new_layerp)
+                        *d++ = 255;
+                    }
+                  else
+                    {
+                      Y = tab[0][0][r] + tab[0][1][g] + tab[0][2][b];
+                      I = tab[1][0][r] + tab[1][1][g] + tab[1][2][b];
+                      Q = tab[2][0][r] + tab[2][1][g] + tab[2][2][b];
+
+                      prev_r = r;
+                      prev_g = g;
+                      prev_b = b;
+                      /*
+                       * Get Y and chroma amplitudes in floating point.
+                       *
+                       * If your C library doesn't have hypot(), just use
+                       * hypot(a,b) = sqrt(a*a, b*b);
+                       *
+                       * Then extract linear (un-gamma-corrected)
+                       * floating-point pixel RGB values.
+                       */
+                      fy = (double)Y / (double)SCALE;
+                      fc = hypot ((double) I / (double) SCALE,
+                                  (double) Q / (double) SCALE);
+
+                      pr = (double) pix_decode (r);
+                      pg = (double) pix_decode (g);
+                      pb = (double) pix_decode (b);
+
+                      /*
+                       * Reducing overall pixel intensity by scaling R,
+                       * G, and B reduces Y, I, and Q by the same factor.
+                       * This changes luminance but not saturation, since
+                       * saturation is determined by the chroma/luminance
+                       * ratio.
+                       *
+                       * On the other hand, by linearly interpolating
+                       * between the original pixel value and a grey
+                       * pixel with the same luminance (R=G=B=Y), we
+                       * change saturation without affecting luminance.
+                       */
+                      if (argp->action == ACT_LREDUX)
+                        {
+                          /*
+                           * Calculate a scale factor that will bring the pixel
+                           * within both chroma and composite limits, if we scale
+                           * luminance and chroma simultaneously.
+                           *
+                           * The calculated chrominance reduction applies
+                           * to the gamma-corrected RGB values that are
+                           * the input to the RGB-to-YIQ operation.
+                           * Multiplying the original un-gamma-corrected
+                           * pixel values by the scaling factor raised to
+                           * the "gamma" power is equivalent, and avoids
+                           * calling gc() and inv_gc() three times each.  */
+                          scale = chroma_lim / fc;
+                          t = compos_lim / (fy + fc);
+                          if (t < scale)
+                            scale = t;
+                          scale = pow (scale, mode[argp->mode].gamma);
+
+                          r = (guint8) pix_encode (scale * pr);
+                          g = (guint8) pix_encode (scale * pg);
+                          b = (guint8) pix_encode (scale * pb);
+                        }
+                      else
+                        { /* ACT_SREDUX hopefully */
+                          /*
+                           * Calculate a scale factor that will bring the
+                           * pixel within both chroma and composite
+                           * limits, if we scale chroma while leaving
+                           * luminance unchanged.
+                           *
+                           * We have to interpolate gamma-corrected RGB
+                           * values, so we must convert from linear to
+                           * gamma-corrected before interpolation and then
+                           * back to linear afterwards.
+                           */
+                          scale = chroma_lim / fc;
+                          t = (compos_lim - fy) / fc;
+                          if (t < scale)
+                            scale = t;
+
+                          pr = gc (pr, argp->mode);
+                          pg = gc (pg, argp->mode);
+                          pb = gc (pb, argp->mode);
+
+                          py = pr * mode[argp->mode].code[0][0] +
+                               pg * mode[argp->mode].code[0][1] +
+                               pb * mode[argp->mode].code[0][2];
+
+                          r = pix_encode (inv_gc (py + scale * (pr - py),
+                                                  argp->mode));
+                          g = pix_encode (inv_gc (py + scale * (pg - py),
+                                                  argp->mode));
+                          b = pix_encode (inv_gc (py + scale * (pb - py),
+                                                  argp->mode));
+                        }
+
+                      *d++ = new_r = r;
+                      *d++ = new_g = g;
+                      *d++ = new_b = b;
+
+                      s += 3;
+
+                      if (src_bpp == 4)
+                        *d++ = *s++;
+                      else if (argp->new_layerp)
+                        *d++ = 255;
+                    }
+                }
+            }
+          else
+            {
+              if (! argp->new_layerp)
+                {
+                  for (i = 0; i < src_bpp; i++)
+                    *d++ = *s++;
+                }
+              else
+                {
+                  s += src_bpp;
+                  d += dest_bpp;
+                }
+            }
+        }
+    }
+
+  gegl_buffer_set (dest_buffer,
+                   GEGL_RECTANGLE (sel_x1, sel_y1, width, height), 0,
+                   dest_format, dst,
+                   GEGL_AUTO_ROWSTRIDE);
+
+  gimp_progress_update (1.0);
+
+  g_free (src);
+  g_free (dst);
+
+  g_object_unref (src_buffer);
+  g_object_unref (dest_buffer);
+
+  if (argp->new_layerp)
+    {
+      gimp_drawable_update (nl, sel_x1, sel_y1, width, height);
+    }
+  else
+    {
+      gimp_drawable_merge_shadow (argp->drawable, TRUE);
+      gimp_drawable_update (argp->drawable, sel_x1, sel_y1, width, height);
+    }
+
+  gimp_displays_flush ();
+
+  return success;
+}
+
+static gboolean
+plugin_dialog (piArgs *argp)
+{
+  GtkWidget *dlg;
+  GtkWidget *hbox;
+  GtkWidget *vbox;
+  GtkWidget *toggle;
+  GtkWidget *frame;
+  gboolean   run;
+
+  gimp_ui_init (PLUG_IN_BINARY, FALSE);
+
+  dlg = gimp_dialog_new (_("Hot"), PLUG_IN_ROLE,
+                         NULL, 0,
+                         gimp_standard_help_func, PLUG_IN_PROC,
+
+                         _("_Cancel"), GTK_RESPONSE_CANCEL,
+                         _("_OK"),     GTK_RESPONSE_OK,
+
+                         NULL);
+
+  gtk_dialog_set_alternative_button_order (GTK_DIALOG (dlg),
+                                           GTK_RESPONSE_OK,
+                                           GTK_RESPONSE_CANCEL,
+                                           -1);
+
+  gimp_window_set_transient (GTK_WINDOW (dlg));
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
+  gtk_container_set_border_width (GTK_CONTAINER (hbox), 12);
+  gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dlg))),
+                      hbox, TRUE, TRUE, 0);
+  gtk_widget_show (hbox);
+
+  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
+  gtk_box_pack_start (GTK_BOX (hbox), vbox, TRUE, TRUE, 0);
+  gtk_widget_show (vbox);
+
+  frame = gimp_int_radio_group_new (TRUE, _("Mode"),
+                                    G_CALLBACK (gimp_radio_button_update),
+                                    &argp->mode, argp->mode,
+
+                                    "N_TSC", MODE_NTSC, NULL,
+                                    "_PAL",  MODE_PAL,  NULL,
+
+                                    NULL);
+
+  gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);
+  gtk_widget_show (frame);
+
+  toggle = gtk_check_button_new_with_mnemonic (_("Create _new layer"));
+  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle), argp->new_layerp);
+  gtk_box_pack_start (GTK_BOX (vbox), toggle, FALSE, FALSE, 0);
+  gtk_widget_show (toggle);
+
+  g_signal_connect (toggle, "toggled",
+                    G_CALLBACK (gimp_toggle_button_update),
+                    &argp->new_layerp);
+
+  frame = gimp_int_radio_group_new (TRUE, _("Action"),
+                                    G_CALLBACK (gimp_radio_button_update),
+                                    &argp->action, argp->action,
+
+                                    _("Reduce _Luminance"),  ACT_LREDUX, NULL,
+                                    _("Reduce _Saturation"), ACT_SREDUX, NULL,
+                                    _("_Blacken"),           ACT_FLAG,   NULL,
+
+                                    NULL);
+
+  gtk_box_pack_start (GTK_BOX (hbox), frame, FALSE, FALSE, 0);
+  gtk_widget_show (frame);
+
+  gtk_widget_show (dlg);
+
+  run = (gimp_dialog_run (GIMP_DIALOG (dlg)) == GTK_RESPONSE_OK);
+
+  gtk_widget_destroy (dlg);
+
+  return run;
+}
+
+/*
+ * build_tab: Build multiply lookup table.
+ *
+ * For each possible pixel value, decode value into floating-point
+ * intensity.  Then do gamma correction required by the video
+ * standard.  Scale the result by our fixed-point scale factor.
+ * Then calculate 9 lookup table entries for this pixel value.
+ *
+ * We also calculate floating-point and scaled integer versions
+ * of our limits here.  This prevents evaluating expressions every pixel
+ * when the compiler is too stupid to evaluate constant-valued
+ * floating-point expressions at compile time.
+ *
+ * For convenience, the limits are #defined using IRE units.
+ * We must convert them here into the units in which YIQ
+ * are measured.  The conversion from IRE to internal units
+ * depends on the pedestal level in use, since as Y goes from
+ * 0 to 1, the signal goes from the pedestal level to 100 IRE.
+ * Chroma is always scaled to remain consistent with Y.
+ */
+static void
+build_tab (int m)
+{
+  double f;
+  int pv;
+
+  for (pv = 0; pv <= MAXPIX; pv++)
+    {
+      f = (double)SCALE * (double)gc((double)pix_decode(pv),m);
+      tab[0][0][pv] = (int)(f * mode[m].code[0][0] + 0.5);
+      tab[0][1][pv] = (int)(f * mode[m].code[0][1] + 0.5);
+      tab[0][2][pv] = (int)(f * mode[m].code[0][2] + 0.5);
+      tab[1][0][pv] = (int)(f * mode[m].code[1][0] + 0.5);
+      tab[1][1][pv] = (int)(f * mode[m].code[1][1] + 0.5);
+      tab[1][2][pv] = (int)(f * mode[m].code[1][2] + 0.5);
+      tab[2][0][pv] = (int)(f * mode[m].code[2][0] + 0.5);
+      tab[2][1][pv] = (int)(f * mode[m].code[2][1] + 0.5);
+      tab[2][2][pv] = (int)(f * mode[m].code[2][2] + 0.5);
+    }
+
+  chroma_lim = (double)CHROMA_LIM / (100.0 - mode[m].pedestal);
+  compos_lim = ((double)COMPOS_LIM - mode[m].pedestal) /
+    (100.0 - mode[m].pedestal);
+
+  ichroma_lim2 = (int)(chroma_lim * SCALE + 0.5);
+  ichroma_lim2 *= ichroma_lim2;
+  icompos_lim = (int)(compos_lim * SCALE + 0.5);
+}
+
+static gboolean
+hotp (guint8 r,
+      guint8 g,
+      guint8 b)
+{
+  int   y, i, q;
+  long  y2, c2;
+
+  /*
+   * Pixel decoding, gamma correction, and matrix multiplication
+   * all done by lookup table.
+   *
+   * "i" and "q" are the two chrominance components;
+   * they are I and Q for NTSC.
+   * For PAL, "i" is U (scaled B-Y) and "q" is V (scaled R-Y).
+   * Since we only care about the length of the chroma vector,
+   * not its angle, we don't care which is which.
+   */
+  y = tab[0][0][r] + tab[0][1][g] + tab[0][2][b];
+  i = tab[1][0][r] + tab[1][1][g] + tab[1][2][b];
+  q = tab[2][0][r] + tab[2][1][g] + tab[2][2][b];
+
+  /*
+   * Check to see if the chrominance vector is too long or the
+   * composite waveform amplitude is too large.
+   *
+   * Chrominance is too large if
+   *
+   *    sqrt(i^2, q^2)  >  chroma_lim.
+   *
+   * The composite signal amplitude is too large if
+   *
+   *    y + sqrt(i^2, q^2)  >  compos_lim.
+   *
+   * We avoid doing the sqrt by checking
+   *
+   *    i^2 + q^2  >  chroma_lim^2
+   * and
+   *    y + sqrt(i^2 + q^2)  >  compos_lim
+   *    sqrt(i^2 + q^2)  >  compos_lim - y
+   *    i^2 + q^2  >  (compos_lim - y)^2
+   *
+   */
+
+  c2 = (long)i * i + (long)q * q;
+  y2 = (long)icompos_lim - y;
+  y2 *= y2;
+
+  if (c2 <= ichroma_lim2 && c2 <= y2)
+    {   /* no problems */
+      return FALSE;
+    }
+
+  return TRUE;
+}