diff --git a/desmume/src/filter/filter.h b/desmume/src/filter/filter.h
index a3900f563..1d33b8d77 100644
--- a/desmume/src/filter/filter.h
+++ b/desmume/src/filter/filter.h
@@ -1,5 +1,5 @@
 /*
-Copyright (C) 2009-2011 DeSmuME team
+Copyright (C) 2009-2012 DeSmuME team
 
 This file is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@ GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with the this software.  If not, see <http://www.gnu.org/licenses/>.
-*/
+*/
 
 
 typedef struct {
@@ -28,6 +28,7 @@ void RenderLQ2X (SSurface Src, SSurface Dst);
 void RenderLQ2XS (SSurface Src, SSurface Dst);
 void RenderHQ2X (SSurface Src, SSurface Dst);
 void RenderHQ4X (SSurface Src, SSurface Dst);
+void RenderHQ4XS (SSurface Src, SSurface Dst);
 void RenderHQ2XS (SSurface Src, SSurface Dst);
 void Render2xSaI (SSurface Src, SSurface Dst);
 void RenderSuper2xSaI (SSurface Src, SSurface Dst);
diff --git a/desmume/src/filter/hq4x.cpp b/desmume/src/filter/hq4x.cpp
index 967902934..857ec48d1 100644
--- a/desmume/src/filter/hq4x.cpp
+++ b/desmume/src/filter/hq4x.cpp
@@ -39,7 +39,9 @@
  */
 
 
-void hq4x_32_def(u32* dst0, u32* dst1, u32* dst2, u32* dst3, const u32* src0, const u32* src1, const u32* src2, unsigned count, unsigned flag)
+void hq4x_32_def(u32* dst0, u32* dst1, u32* dst2, u32* dst3,
+				 const u32* src0, const u32* src1, const u32* src2,
+				 unsigned count, unsigned flag)
 {
 	unsigned i;
 
@@ -111,25 +113,190 @@ void hq4x_32_def(u32* dst0, u32* dst1, u32* dst2, u32* dst3, const u32* src0, co
 	}
 }
 
+void hq4xS_32_def(u32* dst0, u32* dst1, u32* dst2, u32* dst3,
+				  const u32* src0, const u32* src1, const u32* src2,
+				  unsigned count, unsigned flag)
+{
+	unsigned i;
+	
+	for(i=0;i<count;++i) {
+		unsigned char mask;
+		
+		u32 c[9];
+		
+		c[1] = src0[0];
+		c[4] = src1[0];
+		c[7] = src2[0];
+		
+		c[0] = src0[-1];
+		c[3] = src1[-1];
+		c[6] = src2[-1];
+		
+		c[2] = src0[1];
+		c[5] = src1[1];
+		c[8] = src2[1];
+		
+		mask = 0;
+		// hq4xS dynamic edge detection:
+		// simply comparing the center color against its surroundings will give bad results in many cases,
+		// so, instead, compare the center color relative to the max difference in brightness of this 3x3 block
+		int brightArray[9];
+		int maxBright = 0, minBright = 999999;
+		for(int j = 0 ; j < 9 ; j++)
+		{
+			const int b = (int)((c[j] & 0xF8));
+			const int g = (int)((c[j] & 0xF800)) >> 8;
+			const int r = (int)((c[j] & 0xF80000)) >> 16;
+			const int bright = r+r+r + g+g+g + b+b;
+			if(bright > maxBright) maxBright = bright;
+			if(bright < minBright) minBright = bright;
+			
+			brightArray[j] = bright;
+		}
+		unsigned int diffBright = ((maxBright - minBright) * 7) >> 4;
+		if(diffBright > 7)
+		{
+			const int centerBright = brightArray[4];
+			if(ABS(brightArray[0] - centerBright) > diffBright)
+				mask |= 1 << 0;
+			if(ABS(brightArray[1] - centerBright) > diffBright)
+				mask |= 1 << 1;
+			if(ABS(brightArray[2] - centerBright) > diffBright)
+				mask |= 1 << 2;
+			if(ABS(brightArray[3] - centerBright) > diffBright)
+				mask |= 1 << 3;
+			if(ABS(brightArray[5] - centerBright) > diffBright)
+				mask |= 1 << 4;
+			if(ABS(brightArray[6] - centerBright) > diffBright)
+				mask |= 1 << 5;
+			if(ABS(brightArray[7] - centerBright) > diffBright)
+				mask |= 1 << 6;
+			if(ABS(brightArray[8] - centerBright) > diffBright)
+				mask |= 1 << 7;
+		}
+		
+#define P(a, b) dst##b[a]
+#define MUR false//(ABS(brightArray[1] - brightArray[5]) > diffBright) // top-right
+#define MDR false//(ABS(brightArray[5] - brightArray[7]) > diffBright) // bottom-right
+#define MDL false//(ABS(brightArray[7] - brightArray[3]) > diffBright) // bottom-left
+#define MUL false//(ABS(brightArray[3] - brightArray[1]) > diffBright) // top-left
+#define I1(p0) c[p0]
+#define I2(i0, i1, p0, p1) interp_32_##i0##i1(c[p0], c[p1])
+#define I3(i0, i1, i2, p0, p1, p2) interp_32_##i0##i1##i2(c[p0], c[p1], c[p2])
+		
+		switch (mask) {
+#include "hq4x.dat"
+		}
+		
+#undef P
+#undef MUR
+#undef MDR
+#undef MDL
+#undef MUL
+#undef I1
+#undef I2
+#undef I3
+		
+		src0 += 1;
+		src1 += 1;
+		src2 += 1;
+		dst0 += 4;
+		dst1 += 4;
+		dst2 += 4;
+		dst3 += 4;
+	}
+}
+
+void hq4x32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+			u8 *dstPtr, u32 dstPitch, int width, int height)
+{
+	u32 *dst0 = (u32 *)dstPtr;
+	u32 *dst1 = dst0 + (dstPitch >> 2);
+	u32 *dst2 = dst1 + (dstPitch >> 2);
+	u32 *dst3 = dst2 + (dstPitch >> 2);
+	
+	u32 *src0 = (u32 *)srcPtr;
+	u32 *src1 = src0 + (srcPitch >> 2);
+	u32 *src2 = src1 + (srcPitch >> 2);
+	hq4x_32_def(dst0, dst1, dst2, dst3, src0, src0, src1, width, 0);
+	
+	int count = height;
+	
+	count -= 2;
+	while(count) {
+		dst0 += dstPitch;
+		dst1 += dstPitch;
+		dst2 += dstPitch;
+		dst3 += dstPitch;
+		hq4x_32_def(dst0, dst1, dst2, dst3, src0, src1, src2, width, 0);
+		src0 = src1;
+		src1 = src2;
+		src2 += srcPitch >> 2;
+		--count;
+	}
+	
+	dst0 += dstPitch;
+	dst1 += dstPitch;
+	dst2 += dstPitch;
+	dst3 += dstPitch;
+	hq4x_32_def(dst0, dst1, dst2, dst3, src0, src1, src1, width, 0);
+}
+
+void hq4x32S(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
+			 u8 *dstPtr, u32 dstPitch, int width, int height)
+{
+	u32 *dst0 = (u32 *)dstPtr;
+	u32 *dst1 = dst0 + (dstPitch >> 2);
+	u32 *dst2 = dst1 + (dstPitch >> 2);
+	u32 *dst3 = dst2 + (dstPitch >> 2);
+	
+	u32 *src0 = (u32 *)srcPtr;
+	u32 *src1 = src0 + (srcPitch >> 2);
+	u32 *src2 = src1 + (srcPitch >> 2);
+	hq4xS_32_def(dst0, dst1, dst2, dst3, src0, src0, src1, width, 0);
+	
+	int count = height;
+	
+	count -= 2;
+	while(count) {
+		dst0 += dstPitch;
+		dst1 += dstPitch;
+		dst2 += dstPitch;
+		dst3 += dstPitch;
+		hq4xS_32_def(dst0, dst1, dst2, dst3, src0, src1, src2, width, 0);
+		src0 = src1;
+		src1 = src2;
+		src2 += srcPitch >> 2;
+		--count;
+	}
+	
+	dst0 += dstPitch;
+	dst1 += dstPitch;
+	dst2 += dstPitch;
+	dst3 += dstPitch;
+	hq4xS_32_def(dst0, dst1, dst2, dst3, src0, src1, src1, width, 0);
+}
 
 void RenderHQ4X (SSurface Src, SSurface Dst)
 {
-
-    u32 *lpSrc, *lpDst;
-
-    lpSrc = (u32*)Src.Surface;
-    lpDst = (u32*)Dst.Surface;
-
-    int dp = Dst.Pitch/2;
-    int sp = Src.Pitch/2;
-    for(int i=0;i<Src.Height;i++)
-    {
-      hq4x_32_def(lpDst,lpDst+dp,lpDst+dp*2,lpDst+dp*3,lpSrc,lpSrc+sp,lpSrc+sp*2,Src.Width,0);
-      lpDst += Dst.Pitch*2;
-      lpSrc += Src.Pitch/2;
-    }
-
-    //hq4x_32_def (lpSrc, Src.Pitch*2,
-    //            lpSrc,
-    //            lpDst, Dst.Pitch*2 , Src.Width, Src.Height);
+	unsigned char *lpSrc, *lpDst;
+	
+	lpSrc = Src.Surface;
+	lpDst = Dst.Surface;
+	
+	hq4x32 (lpSrc, Src.Pitch*2,
+			lpSrc,
+			lpDst, Dst.Pitch*2 , Src.Width, Src.Height);
+}
+
+void RenderHQ4XS (SSurface Src, SSurface Dst)
+{
+	unsigned char *lpSrc, *lpDst;
+	
+	lpSrc = Src.Surface;
+	lpDst = Dst.Surface;
+	
+	hq4x32S (lpSrc, Src.Pitch*2,
+			 lpSrc,
+			 lpDst, Dst.Pitch*2 , Src.Width, Src.Height);
 }