--- trunk/xvidcore/src/quant/adapt_quant.c	2002/06/19 08:46:57	224
+++ trunk/xvidcore/src/quant/adapt_quant.c	2002/10/19 12:20:33	605
@@ -1,3 +1,38 @@
+/*****************************************************************************
+ *
+ *  XVID MPEG-4 VIDEO CODEC
+ *  - Adaptive quantization functions -
+ *
+ *  Copyright(C) 2002 Peter Ross <pross@xvid.org>
+ *               2002 Christoph Lampert <gruel@web.de>
+ *
+ *  This program is an implementation of a part of one or more MPEG-4
+ *  Video tools as specified in ISO/IEC 14496-2 standard.  Those intending
+ *  to use this software module in hardware or software products are
+ *  advised that its use may infringe existing patents or copyrights, and
+ *  any such use would be at such party's own risk.  The original
+ *  developer of this software module and his/her company, and subsequent
+ *  editors and their companies, will have no liability for use of this
+ *  software or modifications or derivatives thereof.
+ *
+ *  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 2 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, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ *  $Id: adapt_quant.c,v 1.11 2002-10-19 12:20:33 edgomez Exp $
+ *
+ ****************************************************************************/
+
 #include "../portab.h"
 #include "adapt_quant.h"
 
@@ -6,6 +41,10 @@
 #define MAX(a,b)      (((a) > (b)) ? (a) : (b))
 #define RDIFF(a,b)    ((int)(a+0.5)-(int)(b+0.5))
 
+/*****************************************************************************
+ * Functions
+ ****************************************************************************/
+
 int
 normalize_quantizer_field(float *in,
 						  int *out,
@@ -65,28 +104,32 @@
 {
 	int i, j, k, l;
 
-	static float *quant;
+	float *quant;
 	unsigned char *ptr;
 	float *val;
-	float global = 0., maxval = 0.;
+	float global = 0.;
+	uint32_t mid_range = 0;
 
-	const float DarkThres = 0.25;
-	const float DarkAmpl = 7.0;
-	
-	const float BrightThres = 4.0;
-	const float BrightAmpl = 5.0;
+	const float DarkAmpl = 14 / 2;
+	const float BrightAmpl = 10 / 2;
+	const float DarkThres = 70;
+	const float BrightThres = 200;
 
-	const char LowestVal = 10;
+	const float GlobalDarkThres = 60;
+	const float GlobalBrightThres = 170;
 
-	const float GlobalBrightThres = 220.0;
-	const float GlobalDarkThres = 20.0;
-	float global_quant = 1.0;
+	const float MidRangeThres = 20;
+	const float UpperLimit = 200;
+	const float LowerLimit = 25;
 
-	if (!quant)
-		if (!(quant = (float *) malloc(mb_width * mb_height * sizeof(float))))
-			return -1;
 
-	val = (float *) malloc(mb_width * mb_height * sizeof(float));
+	if (!(quant = (float *) malloc(mb_width * mb_height * sizeof(float))))
+		return(-1);
+
+	if(!(val = (float *) malloc(mb_width * mb_height * sizeof(float)))) {
+		free(quant);
+		return(-1);
+	}
 
 	for (k = 0; k < mb_height; k++) {
 		for (l = 0; l < mb_width; l++)	// do this for all macroblocks individually 
@@ -100,38 +143,42 @@
 
 			for (i = 0; i < 16; i++)
 				for (j = 0; j < 16; j++)
-				{
-					if( ptr[i * stride + j] < LowestVal )
-						ptr[i * stride + j] = 0;
 					val[k * mb_width + l] += ptr[i * stride + j];
-				}
 			val[k * mb_width + l] /= 256.;
-			global += val[k * mb_width + l];
-			if( val[k * mb_width + l] > maxval )
-				maxval = val[k * mb_width + l];
+			global +=val[k * mb_width + l];
+
+			if ((val[k * mb_width + l] > LowerLimit) &&
+				(val[k * mb_width + l] < UpperLimit))
+				mid_range++;
 		}
 	}
 
-	global /= mb_width * mb_height;
-	maxval /= global;
-	if( global < GlobalDarkThres )
-		global_quant *= -1.0;
-	else if ( global < GlobalBrightThres )
-		global_quant = 0.0;
+	global /=mb_width * mb_height;
 
-	for (k = 0; k < mb_height; k++) {
-		for (l = 0; l < mb_width; l++)	// do this for all macroblocks individually 
-		{
-			val[k * mb_width + l] /= global;
-			if (val[k * mb_width + l] < DarkThres)
-				quant[k * mb_width + l] += global_quant +
-					DarkAmpl * (DarkThres - val[k * mb_width + l]) / DarkThres;
-			else if (val[k * mb_width + l] > BrightThres)
-				quant[k * mb_width + l] += global_quant +
-					BrightAmpl * (val[k * mb_width + l] - BrightThres) / (maxval - BrightThres);
+	if (((global <GlobalBrightThres) &&(global >GlobalDarkThres))
+		|| (mid_range < MidRangeThres)) {
+		for (k = 0; k < mb_height; k++) {
+			for (l = 0; l < mb_width; l++)	// do this for all macroblocks individually 
+			{
+				if (val[k * mb_width + l] < DarkThres)
+					quant[k * mb_width + l] +=
+						DarkAmpl * (DarkThres -
+									val[k * mb_width + l]) / DarkThres;
+				else if (val[k * mb_width + l] > BrightThres)
+					quant[k * mb_width + l] +=
+						BrightAmpl * (val[k * mb_width + l] -
+									  BrightThres) / (255 - BrightThres);
+			}
 		}
 	}
+
+	i = normalize_quantizer_field(quant, intquant,
+								  mb_width * mb_height,
+								  min_quant, max_quant);
+
 	free(val);
-	return normalize_quantizer_field(quant, intquant, mb_width * mb_height,
-									 min_quant, max_quant);
+	free(quant);
+
+	return(i);
+
 }