1 files changed, 147 insertions, 0 deletions
diff --git a/mpeglib/lib/util/render/dither/colorTable8Bit.cpp b/mpeglib/lib/util/render/dither/colorTable8Bit.cpp
new file mode 100644
index 00000000..57c533de
--- /dev/null
+++ b/mpeglib/lib/util/render/dither/colorTable8Bit.cpp
@@ -0,0 +1,147 @@
+/*
+  colorTables for 8 Bit depth
+  Copyright (C) 2000  Martin Vogt
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Library General Public License as published by
+  the Free Software Foundation.
+
+  For more information look at the file COPYRIGHT in this package
+
+ */
+
+
+#include "colorTable8Bit.h"
+
+
+ColorTable8Bit::ColorTable8Bit() {
+
+  lum_values = new int[LUM_RANGE];
+  cr_values = new int[CR_RANGE];
+  cb_values = new int[CB_RANGE];
+
+
+  /* We can exploit cache by allocating contiguous blocks */
+  
+  colortab = new TABTYPE[5*256];
+  
+  Cr_r_tab = &colortab[0*256];
+  Cr_g_tab = &colortab[1*256];
+  Cb_g_tab = &colortab[2*256];
+  Cb_b_tab = &colortab[3*256];
+  L_tab    = &colortab[4*256];
+
+  init8BitColor();
+} 
+
+
+ColorTable8Bit::~ColorTable8Bit() {
+  delete lum_values;
+  delete cr_values;
+  delete cb_values;
+  delete colortab;
+}
+
+
+void ColorTable8Bit::init8BitColor() {
+  int i;
+
+
+
+  for (i=0; i<LUM_RANGE; i++) {
+    lum_values[i]  = ((i * 256) / (LUM_RANGE)) + (256/(LUM_RANGE*2));
+    L_tab[i] = lum_values[i];
+    if (gammaCorrectFlag) {
+      L_tab[i] = GAMMA_CORRECTION(L_tab[i]);
+    }
+
+  }
+
+  
+  for (i=0; i<CR_RANGE; i++) {
+    register double tmp;
+    if (chromaCorrectFlag) {
+      tmp = ((i * 256) / (CR_RANGE)) + (256/(CR_RANGE*2));
+      Cr_r_tab[i]=(TABTYPE) ((0.419/0.299)*CHROMA_CORRECTION128D(tmp-128.0));
+      Cr_g_tab[i]=(TABTYPE) (-(0.299/0.419)*CHROMA_CORRECTION128D(tmp-128.0));
+      cr_values[i] = CHROMA_CORRECTION256(tmp);
+    } else {
+      tmp = ((i * 256) / (CR_RANGE)) + (256/(CR_RANGE*2));
+      Cr_r_tab[i] = (TABTYPE)  ((0.419/0.299) * (tmp - 128.0));
+      Cr_g_tab[i] = (TABTYPE) (-(0.299/0.419) * (tmp - 128.0));
+      cr_values[i] = (int) tmp;
+    }
+  }
+
+  
+  for (i=0; i<CB_RANGE; i++) {
+    register double tmp;
+    if (chromaCorrectFlag) {
+      tmp = ((i * 256) / (CB_RANGE)) + (256/(CB_RANGE*2));
+      Cb_g_tab[i]=(TABTYPE) (-(0.114/0.331)*CHROMA_CORRECTION128D(tmp-128.0));
+      Cb_b_tab[i]=(TABTYPE) ((0.587/0.331)*CHROMA_CORRECTION128D(tmp-128.0));
+      cb_values[i] = CHROMA_CORRECTION256(tmp);
+    } else {
+      tmp = ((i * 256) / (CB_RANGE)) + (256/(CB_RANGE*2));
+      Cb_g_tab[i] = (TABTYPE) (-(0.114/0.331) * (tmp - 128.0));
+      Cb_b_tab[i] = (TABTYPE) ((0.587/0.331) * (tmp - 128.0));
+      cb_values[i] = (int) tmp;
+    }
+  }
+}
+
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ConvertColor --
+ *
+ *      Given a l, cr, cb tuple, converts it to r,g,b.
+ *
+ * Results:
+ *      r,g,b values returned in pointers passed as parameters.
+ *
+ * Side effects:
+ *      None.
+ *
+ *--------------------------------------------------------------
+ */
+void ColorTable8Bit::ConvertColor(unsigned int l, unsigned int cr, 
+				  unsigned int cb, unsigned char* r, 
+				  unsigned char* g, unsigned char* b) {
+
+  double fl, fr, fg, fb;
+
+  /*
+   * Old method w/o lookup table
+   *
+   * fl = 1.164*(((double) l)-16.0);
+   * fcr =  ((double) cr) - 128.0;
+   * fcb =  ((double) cb) - 128.0;
+   *
+   * fr = fl + (1.366 * fcr);
+   * fg = fl - (0.700 * fcr) - (0.334 * fcb);
+   * fb = fl + (1.732 * fcb);
+   */
+  
+  fl = L_tab[l];
+
+  fr = fl + Cr_r_tab[cr];
+  fg = fl + Cr_g_tab[cr] + Cb_g_tab[cb];
+  fb = fl + Cb_b_tab[cb];
+
+  if (fr < 0.0) fr = 0.0;
+  else if (fr > 255.0) fr = 255.0;
+
+  if (fg < 0.0) fg = 0.0;
+  else if (fg > 255.0) fg = 255.0;
+
+  if (fb < 0.0) fb = 0.0;
+  else if (fb > 255.0) fb = 255.0;
+
+  *r = (unsigned char) fr;
+  *g = (unsigned char) fg;
+  *b = (unsigned char) fb;
+
+}