diff --git a/shaders/debayer.frag b/shaders/debayer.frag
index 9e402dc..778955d 100644
--- a/shaders/debayer.frag
+++ b/shaders/debayer.frag
@@ -2,7 +2,7 @@
 
 uniform sampler2D qt_Texture0;
 in vec2 qt_TexCoord0;
-in vec4 center;
+in vec2 center;
 out vec4 color;
 
 #define f(x, y) texelFetch(qt_Texture0, icenter + ivec2(x, y), 0).r
@@ -10,7 +10,7 @@ out vec4 color;
 void main(void)
 {
     ivec2 texSize = textureSize(qt_Texture0, 0);
-    ivec2 icenter = ivec2(center.zw);
+    ivec2 icenter = ivec2(center);
     ivec2 alternate = icenter % 2;
 
     // cross, checker, theta, phi
diff --git a/shaders/debayer.vert b/shaders/debayer.vert
index f746538..bc4ea25 100644
--- a/shaders/debayer.vert
+++ b/shaders/debayer.vert
@@ -4,8 +4,7 @@ uniform sampler2D qt_Texture0;
 in vec2 qt_Vertex;
 in vec2 qt_MultiTexCoord0;
 out vec2 qt_TexCoord0;
-out vec4 center;
-uniform vec2 viewport;
+out vec2 center;
 
 void main(void)
 {
@@ -13,6 +12,5 @@ void main(void)
     gl_Position = vec4(qt_Vertex, 0.0, 1.0);
     qt_TexCoord0 = qt_MultiTexCoord0;
     qt_TexCoord0.y = 1.0 - qt_TexCoord0.y;
-    center.xy = qt_TexCoord0;
-    center.zw = qt_TexCoord0 * texSize.xy;
+    center = qt_TexCoord0 * texSize.xy;
 }