diff --git a/hlsl/ntsc.fx b/hlsl/ntsc.fx
index ed07e37a4cc..107be16af16 100644
--- a/hlsl/ntsc.fx
+++ b/hlsl/ntsc.fx
@@ -108,7 +108,7 @@ static const int HalfSampleCount = SampleCount / 2;
 
 float4 GetCompositeYIQ(float2 TexCoord)
 {
-	float2 SourceTexelDims = 1.0f / SourceDims;	
+	float2 SourceTexelDims = 1.0f / SourceDims;
 	float2 SourceRes = SourceDims * SourceRect;
 
 	float2 PValueSourceTexel = float2(PValue, 0.0f) * SourceTexelDims;
@@ -131,12 +131,13 @@ float4 GetCompositeYIQ(float2 TexCoord)
 	float4 I = float4(dot(Texel0, IDot), dot(Texel1, IDot), dot(Texel2, IDot), dot(Texel3, IDot));
 	float4 Q = float4(dot(Texel0, QDot), dot(Texel1, QDot), dot(Texel2, QDot), dot(Texel3, QDot));
 
-	float4 W = PI2 * CCValue * ScanTime;
+	float W = PI2 * CCValue * ScanTime;
+	float WoPI = W / PI;
 
-	float4 T = HPosition
-		+ (AValue / 360.0f * SourceRes.y) * VPosition
-		+ (BValue / 360.0f)
-		+ (SignalOffset / 360.0f);
+	float HOffset = (BValue + SignalOffset) / WoPI;
+	float VScale = (AValue * SourceRes.y) / WoPI;
+
+	float4 T = HPosition + HOffset + VPosition * VScale;
 	float4 TW = T * W;
 
 	float4 CompositeYIQ = Y + I * cos(TW) + Q * sin(TW);
@@ -171,7 +172,11 @@ float4 ps_main(PS_INPUT Input) : COLOR
 	float PI2Length = PI2 / SampleCount;
 
 	float W = PI2 * CCValue * ScanTime;
-	
+	float WoPI = W / PI;
+
+	float HOffset = (BValue + SignalOffset) / WoPI;
+	float VScale = (AValue * SourceRes.y) / WoPI;
+
 	float4 YAccum = 0.0f;
 	float4 IAccum = 0.0f;
 	float4 QAccum = 0.0f;
@@ -190,12 +195,8 @@ float4 ps_main(PS_INPUT Input) : COLOR
 
 		float4 C = GetCompositeYIQ(float2(Cx.r, Cy.r));
 
-		float4 T = HPosition
-			+ (AValue / 360.0f * SourceRes.y) * VPosition
-			+ (BValue / 360.0f)
-			+ (SignalOffset / 360.0f);
-		float4 WT = W * T
-			+ OValue;
+		float4 T = HPosition + HOffset + VPosition * VScale;
+		float4 WT = W * T + OValue;
 
 		float4 SincKernel = 0.54f + 0.46f * cos(PI2Length * n4);
 
diff --git a/src/osd/modules/render/d3d/d3dhlsl.cpp b/src/osd/modules/render/d3d/d3dhlsl.cpp
index 8a60eaa5190..712646f7a9a 100644
--- a/src/osd/modules/render/d3d/d3dhlsl.cpp
+++ b/src/osd/modules/render/d3d/d3dhlsl.cpp
@@ -990,7 +990,7 @@ int shaders::create_resources(bool reset)
 	deconverge_effect->add_uniform("RadialConvergeY", uniform::UT_VEC3, uniform::CU_CONVERGE_RADIAL_Y);
 
 	focus_effect->add_uniform("Defocus", uniform::UT_VEC2, uniform::CU_FOCUS_SIZE);
-	
+
 	phosphor_effect->add_uniform("Phosphor", uniform::UT_VEC3, uniform::CU_PHOSPHOR_LIFE);
 
 	post_effect->add_uniform("VignettingAmount", uniform::UT_FLOAT, uniform::CU_POST_VIGNETTING); // backward compatibility
@@ -1231,7 +1231,7 @@ int shaders::ntsc_pass(render_target *rt, int source_index, poly_info *poly, int
 	{
 		return next_index;
 	}
-	
+
 	float signal_offset = curr_texture->get_cur_frame() == 0
 		? 0.0f
 		: options->yiq_jitter;
@@ -1241,7 +1241,7 @@ int shaders::ntsc_pass(render_target *rt, int source_index, poly_info *poly, int
 	curr_effect = ntsc_effect;
 	curr_effect->update_uniforms();
 	curr_effect->set_float("SignalOffset", signal_offset);
-	
+
 	next_index = rt->next_index(next_index);
 	blit(rt->native_target[next_index], true, D3DPT_TRIANGLELIST, 0, 2);
 
@@ -2778,7 +2778,7 @@ static INT32 slider_ntsc_enable(running_machine &machine, void *arg, std::string
 }
 
 // static INT32 slider_ntsc_phase_count(running_machine &machine, void *arg, std::string *str, INT32 newval)
-// {	
+// {
 // 	hlsl_options *options = (hlsl_options*)arg;
 // 	if (newval != SLIDER_NOCHANGE)
 // 	{
@@ -3066,7 +3066,7 @@ void uniform::update()
 			break;
 		}
 		case CU_SOURCE_RECT:
-		{			
+		{
 			bool prepare_vector =
 				d3d->window().machine().first_screen()->screen_type() == SCREEN_TYPE_VECTOR;
 
@@ -3076,7 +3076,7 @@ void uniform::update()
 				m_shader->set_vector("SourceRect", 2, delta);
 				break;
 			}
-			
+
 			if (shadersys->curr_texture != NULL)
 			{
 				vec2f delta = shadersys->curr_texture->get_uvstop() - shadersys->curr_texture->get_uvstart();