--- branches/dev-api-4/xvidcore/src/motion/gmc.c	2003/10/01 23:23:01	1161
+++ branches/dev-api-4/xvidcore/src/motion/gmc.c	2004/03/31 13:40:59	1394
@@ -19,7 +19,7 @@
  *  along with this program ; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  *
- * $Id: gmc.c,v 1.1.2.6 2003-10-01 23:23:01 edgomez Exp $
+ * $Id: gmc.c,v 1.1.2.9 2004-03-31 13:40:59 Skal Exp $
  *
  ****************************************************************************/
 
@@ -70,12 +70,17 @@
 			U += dUx; V += dVx;
 
 			if (u > 0 && u <= W) { ri = MTab[u&15]; Offset = u>>4;	}
-			else if (u > W) Offset = W>>4;
-			else Offset = -1;
+			else {
+				if (u > W) Offset = W>>4;
+				else Offset = 0;
+				ri = MTab[0];
+			}
 
 			if (v > 0 && v <= H) { rj = MTab[v&15]; Offset += (v>>4)*srcstride; }
-			else if (v > H) Offset += (H>>4)*srcstride;
-			else Offset -= srcstride;
+			else {
+				if (v > H) Offset += (H>>4)*srcstride;
+				rj = MTab[0];
+			}
 
 			f0	= src[Offset + 0];
 			f0 |= src[Offset + 1] << 16;
@@ -131,18 +136,17 @@
 				ri = MTab[u&15];
 				Offset = u>>4;
 			} else {
-				ri = 16;
 				if (u>W) Offset = W>>4;
-				else Offset = -1;
+				else Offset = 0;
+				ri = MTab[0];
 			}
 
 			if (v > 0 && v <= H) {
 				rj = MTab[v&15];
 				Offset += (v>>4)*srcstride;
 			} else {
-				rj = 16;
 				if (v>H) Offset += (H>>4)*srcstride;
-				else Offset -= srcstride;
+				rj = MTab[0];
 			}
 
 			f0	= uSrc[Offset + 0];
@@ -214,17 +218,23 @@
 
 	int32_t uo = This->Uo + (x<<8);	 /* ((16*x)<<4) */
 	int32_t vo = This->Vo + (y<<8);
-	const uint32_t ri = MTab[uo & 15];
-	const uint32_t rj = MTab[vo & 15];
+	uint32_t ri = MTab[uo & 15];
+	uint32_t rj = MTab[vo & 15];
 	int i, j;
 
 	int32_t Offset;
-	if ((uint32_t)vo<=(uint32_t)H) Offset	= (vo>>4)*srcstride;
-	else if (vo>H)				 Offset	= ( H>>4)*srcstride;
-	else							 Offset	=-16*srcstride;
-	if ((uint32_t)uo<=(uint32_t)W) Offset += (uo>>4);
-	else if (uo>W)				 Offset += ( W>>4);
-	else							 Offset -= 16;
+	if (vo>=(-16*4) && vo<=H) Offset = (vo>>4)*srcstride;
+	else {
+		if (vo>H) Offset = ( H>>4)*srcstride;
+		else Offset =-16*srcstride;
+		rj = MTab[0];
+	}
+	if (uo>=(-16*4) && uo<=W) Offset += (uo>>4);
+	else {
+		if (uo>W) Offset += (W>>4);
+		else Offset -= 16;
+		ri = MTab[0];
+	}
 
 	Dst += 16;
 
@@ -259,17 +269,23 @@
 
 	int32_t uo = This->Uco + (x<<7);
 	int32_t vo = This->Vco + (y<<7);
-	const uint32_t rri = MTab[uo & 15];
-	const uint32_t rrj = MTab[vo & 15];
+	uint32_t rri = MTab[uo & 15];
+	uint32_t rrj = MTab[vo & 15];
 	int i, j;
 
 	int32_t Offset;
-	if ((uint32_t)vo<=(uint32_t)H) Offset = (vo>>4)*srcstride;
-	else if (vo>H) Offset = ( H>>4)*srcstride;
-	else Offset =-8*srcstride;
-	if ((uint32_t)uo<=(uint32_t)W) Offset += (uo>>4);
-	else if (uo>W) Offset += (W>>4);
-	else Offset -= 8;
+	if (vo>=(-8*4) && vo<=H) Offset	= (vo>>4)*srcstride;
+	else {
+		if (vo>H) Offset = ( H>>4)*srcstride;
+		else Offset =-8*srcstride;
+		rrj = MTab[0];
+	}
+	if (uo>=(-8*4) && uo<=W) Offset	+= (uo>>4);
+	else {
+		if (uo>W) Offset += ( W>>4);
+		else Offset -= 8;
+		rri = MTab[0];
+	}
 
 	uDst += 8;
 	vDst += 8;
@@ -325,16 +341,15 @@
 	gmc->num_wp = nb_pts;
 
 	/* reduce the number of points, if possible */
-	if (nb_pts<3 || (pts->duv[2].x==-pts->duv[1].y && pts->duv[2].y==pts->duv[1].x)) {
-	if (nb_pts<2 || (pts->duv[1].x==0 && pts->duv[1].y==0)) {
-		if (nb_pts<1 || (pts->duv[0].x==0 && pts->duv[0].y==0)) {
-		nb_pts = 0;
-		}
-		else nb_pts = 1;
-	}
-	else nb_pts = 2;
-	}
-	else nb_pts = 3;
+	if (nb_pts<2 || (pts->duv[2].x==0 && pts->duv[2].y==0 && pts->duv[1].x==0 && pts->duv[1].y==0 )) {
+  	if (nb_pts<2 || (pts->duv[1].x==0 && pts->duv[1].y==0)) {
+	  	if (nb_pts<1 || (pts->duv[0].x==0 && pts->duv[0].y==0)) {
+		    nb_pts = 0;
+  		}
+	  	else nb_pts = 1;
+  	}
+	  else nb_pts = 2;
+  }
 
 	/* now, nb_pts stores the actual number of points required for interpolation */
 
@@ -364,15 +379,11 @@
 	gmc->dU[0] = 16*Ws + RDIV( 8*Ws*pts->duv[1].x, width );	 /* dU/dx */
 	gmc->dV[0] =		 RDIV( 8*Ws*pts->duv[1].y, width );	 /* dV/dx */
 
-/*	 disabled, because possibly buggy? */
-
-#if 0
 	if (nb_pts==2) {
 		gmc->dU[1] = -gmc->dV[0];	/* -Sin */
 		gmc->dV[1] =	gmc->dU[0] ;	/* Cos */
 	}
 	else
-#endif
 	{
 		const int Beta = log2bin(height-1);
 		const int Hs = 1<<Beta;