diff --git a/libfreerdp/primitives/prim_YCoCg.c b/libfreerdp/primitives/prim_YCoCg.c
index a3dc1f05b..0295e3e3c 100644
--- a/libfreerdp/primitives/prim_YCoCg.c
+++ b/libfreerdp/primitives/prim_YCoCg.c
@@ -26,44 +26,44 @@
 
 #include "prim_internal.h"
 
+/* helper function to convert raw 8 bit values to signed 16bit values.
+ */
+static INT16 convert(UINT8 raw, int shift)
+{
+	const int cll = shift - 1; /* -1 builds in the /2's */
+	return (INT16)((INT8)(raw << cll));
+}
+
 /* ------------------------------------------------------------------------- */
 static pstatus_t general_YCoCgToRGB_8u_AC4R(const BYTE* pSrc, INT32 srcStep, BYTE* pDst,
                                             UINT32 DstFormat, INT32 dstStep, UINT32 width,
                                             UINT32 height, UINT8 shift, BOOL withAlpha)
 {
-	BYTE A;
 	UINT32 x, y;
-	BYTE* dptr = pDst;
-	const BYTE* sptr = pSrc;
-	INT16 Cg, Co, Y, T, R, G, B;
 	const DWORD formatSize = GetBytesPerPixel(DstFormat);
 	fkt_writePixel writePixel = getPixelWriteFunction(DstFormat, TRUE);
-	int cll = shift - 1; /* -1 builds in the /2's */
-	UINT32 srcPad = srcStep - (width * 4);
-	UINT32 dstPad = dstStep - (width * formatSize);
 
 	for (y = 0; y < height; y++)
 	{
+		const BYTE* sptr = &pSrc[srcStep * y];
+		BYTE* dptr = &pDst[dstStep * y];
 		for (x = 0; x < width; x++)
 		{
 			/* Note: shifts must be done before sign-conversion. */
-			Cg = (INT16)((INT8)((*sptr++) << cll));
-			Co = (INT16)((INT8)((*sptr++) << cll));
-			Y = (INT16)(*sptr++); /* UINT8->INT16 */
-			A = *sptr++;
+			const INT16 Cg = convert(*sptr++, shift);
+			const INT16 Co = convert(*sptr++, shift);
+			const INT16 Y = *sptr++; /* UINT8->INT16 */
+			const INT16 T = Y - Cg;
+			const INT16 B = T + Co;
+			const INT16 G = Y + Cg;
+			const INT16 R = T - Co;
+			BYTE A = *sptr++;
 
 			if (!withAlpha)
 				A = 0xFFU;
 
-			T = Y - Cg;
-			B = T + Co;
-			G = Y + Cg;
-			R = T - Co;
 			dptr = writePixel(dptr, formatSize, DstFormat, CLIP(R), CLIP(G), CLIP(B), A);
 		}
-
-		sptr += srcPad;
-		dptr += dstPad;
 	}
 
 	return PRIMITIVES_SUCCESS;