diff --git a/src/add-ons/media/plugins/avcodec/gfx_conv_c.cpp b/src/add-ons/media/plugins/avcodec/gfx_conv_c.cpp
index 5383e21076..ecc7e51ea2 100644
--- a/src/add-ons/media/plugins/avcodec/gfx_conv_c.cpp
+++ b/src/add-ons/media/plugins/avcodec/gfx_conv_c.cpp
@@ -176,41 +176,51 @@ void gfx_conv_yuv411p_rgb32_c(AVFrame *in, AVFrame *out, int width, int height)
 
 void gfx_conv_yuv420p_rgb32_c(AVFrame *in, AVFrame *out, int width, int height)
 {
+	uint32 poutInc = 2 * out->linesize[0];
+	uint32 *poutEven = (uint32 *)out->data[0];
+	uint32 *poutOdd = (uint32 *)(out->linesize[0] + (uint8 *)poutEven);
+	
+	uint32 pi1Inc = in->linesize[0];
+	uint32 pi1Inc2 = 2 * pi1Inc;
+	uint32 pi2Inc = in->linesize[1];
+	uint32 pi3Inc = in->linesize[2];
+	
+	uint8 *pi1Base = (uint8 *)in->data[0];
+	uint8 *pi2Base = (uint8 *)in->data[1];
+	uint8 *pi3Base = (uint8 *)in->data[2];
 
-	for (int i = 0; i < height; i++) {
+	uint32 runs = height / 2;
+	for (uint32 i = 0; i < runs; i++) {
 
-		uint32 *pout = (uint32 *)(i * out->linesize[0] + (uint8 *)out->data[0]);
-		uint8 *pi1 = i * in->linesize[0] + (uint8 *)in->data[0];
-		uint8 *pi2 = (i/2) * in->linesize[1] + (uint8 *)in->data[1];
-		uint8 *pi3 = (i/2) * in->linesize[2] + (uint8 *)in->data[2];
+		uint8 *pi1Even = i * pi1Inc2 + pi1Base;
+		uint8 *pi1Odd = pi1Inc + pi1Even;
+		uint8 *pi2 = i * pi2Inc + pi2Base;
+		uint8 *pi3 = i *pi3Inc + pi3Base;
 
-		for (int j = 0; j < width; j+= 2) {
+		for (uint32 j = 0; j < (uint32)width; j+= 2) {
 
-			int32 Cb, Cr, Y0, Y1, Cr_R, Cr_G, Cb_G, Cb_B, R, G, B;
-		
-			uint32 Y = *(uint16 *)pi1;
-			pi1 += 2;
+			int32 Cr_R, Cr_G, Cb_G, Cb_B;
+			register int32 Y0, Y1, R, G, B;
+
+			B = - 128 + *(pi2++);
+			R = - 128 + *(pi3++);
+			Cr_R = R * 52298;
+			Cr_G = R * -26640;
+			Cb_G = B * -12845;
+			Cb_B = B * 66493;
+
+			G = *(uint16 *)pi1Even;
+			pi1Even += 2;
+			Y0 = ((G & 0x000000ff) - 16) * 38142;
+			Y1 = (((G & 0x0000ff00) >> 8) - 16) * 38142;
 			
-			Y1 = (((Y & 0x0000ff00) >> 8) - 16) * 38142;
-			Y0 = ((Y & 0x000000ff) - 16) * 38142;
-
-			Cb = - 128 + *pi2;
-			Cr = - 128 + *pi3;
-			pi2 ++;
-			pi3 ++;
-
-			Cr_R = Cr * 52298;
-			Cr_G = Cr * -26640;
-			Cb_G = Cb * -12845;
-			Cb_B = Cb * 66493;
-
 			R = (Y0 + Cr_R) >> 15;
 			if (R < 0) R = 0; else if (R > 255) R = 255;
 			G = (Y0 + Cr_G + Cb_G) >> 15;
 			if (G < 0) G = 0; else if (G > 255) G = 255;
 			B = (Y0 + Cb_B) >> 15;
 			if (B < 0) B = 0; else if (B > 255) B = 255;
-			pout[j] = (R << 16) | (G << 8) | B;
+			poutEven[j] = (R << 16) | (G << 8) | B;
 			
 			R = (Y1 + Cr_R) >> 15;
 			if (R < 0) R = 0; else if (R > 255) R = 255;
@@ -218,9 +228,34 @@ void gfx_conv_yuv420p_rgb32_c(AVFrame *in, AVFrame *out, int width, int height)
 			if (G < 0) G = 0; else if (G > 255) G = 255;
 			B = (Y1 + Cb_B) >> 15;
 			if (B < 0) B = 0; else if (B > 255) B = 255;
-			pout[j + 1] = (R << 16) | (G << 8) | B;
+			poutEven[j + 1] = (R << 16) | (G << 8) | B;
 
+			G = *(uint16 *)pi1Odd;
+			pi1Odd += 2;
+			Y0 = ((G & 0x000000ff) - 16) * 38142;
+			Y1 = (((G & 0x0000ff00) >> 8) - 16) * 38142;
+
+			R = (Y0 + Cr_R) >> 15;
+			if (R < 0) R = 0; else if (R > 255) R = 255;
+			G = (Y0 + Cr_G + Cb_G) >> 15;
+			if (G < 0) G = 0; else if (G > 255) G = 255;
+			B = (Y0 + Cb_B) >> 15;
+			if (B < 0) B = 0; else if (B > 255) B = 255;
+			poutOdd[j] = (R << 16) | (G << 8) | B;
+			
+			R = (Y1 + Cr_R) >> 15;
+			if (R < 0) R = 0; else if (R > 255) R = 255;
+			G = (Y1 + Cr_G + Cb_G) >> 15;
+			if (G < 0) G = 0; else if (G > 255) G = 255;
+			B = (Y1 + Cb_B) >> 15;
+			if (B < 0) B = 0; else if (B > 255) B = 255;
+			poutOdd[j + 1] = (R << 16) | (G << 8) | B;
 		}
+		poutEven = (uint32 *)(poutInc + (uint8 *)poutEven);
+		poutOdd = (uint32 *)(poutInc + (uint8 *)poutOdd);
+	}
+	if (height & 1) {
+		// XXX special case for last line if height not multiple of 2 goes here
+		memset((height - 1) * out->linesize[0] + (uint8 *)out->data[0], 0, width * 4);
 	}
 }
-