Fix for unbiased integer

division error

Author: DTL2020

Sources/MDegrainN.cpp

@@ -1948,8 +1948,10 @@ void	MDegrainN::use_block_uv(
   if (usable_flag)
   {
     const FakeBlockData &block = c_info._clip_sptr->GetBlock(0, i);
-    const int blx = block.GetX() * nPel + block.GetMV().x;
-    const int bly = block.GetY() * nPel + block.GetMV().y;
+    int blx = block.GetX() * nPel + block.GetMV().x;
+    int bly = block.GetY() * nPel + block.GetMV().y;
+    if (nLogxRatioUV_super == 1) blx++; // add bias for integer division for 4:2:x formats
+    if (nLogyRatioUV_super == 1) bly++; // add bias for integer division for 4:2:x formats
     p = plane_ptr->GetPointer(blx >> nLogxRatioUV_super, bly >> nLogyRatioUV_super);
     np = plane_ptr->GetPitch();
     const sad_t block_sad = block.GetSAD(); // SAD of MV Block. Scaled to MVClip's bits_per_pixel;

Sources/MVDegrain3.cpp

@@ -1544,7 +1544,9 @@ MV_FORCEINLINE void MVDegrainX::use_block_uv(const BYTE * &p, int &np, int &WRef
   {
     const FakeBlockData &block = mvclip.GetBlock(0, i);
     int blx = block.GetX() * nPel + block.GetMV().x;
-    int bly = block.GetY() * nPel + block.GetMV().y;
+    int bly = block.GetY() * nPel + block.GetMV().y;
+    if (nLogxRatioUV_super == 1) blx++; // add bias for integer division for 4:2:x formats
+    if (nLogyRatioUV_super == 1) bly++; // add bias for integer division for 4:2:x formats
     p = pPlane->GetPointer(blx >> nLogxRatioUV_super, bly >> nLogyRatioUV_super); // pixelsize - aware
     np = pPlane->GetPitch();
     sad_t blockSAD = block.GetSAD();  // SAD of MV Block. Scaled to MVClip's bits_per_pixel;

Sources/PlaneOfBlocks.h

@@ -409,18 +409,23 @@ class PlaneOfBlocks
 
   MV_FORCEINLINE const uint8_t* GetRefBlockU(WorkingArea& workarea, int nVx, int nVy)
   {
+    int nVx1 = (nLogxRatioUV == 1) ? nVx + 1 : nVx;
+    int nVy1 = (nLogxRatioUV == 1) ? nVy + 1 : nVy;
     return
-      (nPel == 2) ? pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <1>((workarea.x[1] << 1) + (nVx >> nLogxRatioUV), (workarea.y[1] << 1) + (nVy >> nLogyRatioUV)) :
-      (nPel == 1) ? pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <0>((workarea.x[1]) + (nVx >> nLogxRatioUV), (workarea.y[1]) + (nVy >> nLogyRatioUV)) :
-      pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <2>((workarea.x[1] << 2) + (nVx >> nLogxRatioUV), (workarea.y[1] << 2) + (nVy >> nLogyRatioUV));
+      (nPel == 2) ? pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <1>((workarea.x[1] << 1) + (nVx1 >> nLogxRatioUV), (workarea.y[1] << 1) + (nVy1 >> nLogyRatioUV)) :
+      (nPel == 1) ? pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <0>((workarea.x[1]) + (nVx1 >> nLogxRatioUV), (workarea.y[1]) + (nVy1 >> nLogyRatioUV)) :
+      pRefFrame->GetPlane(UPLANE)->GetAbsolutePointerPel <2>((workarea.x[1] << 2) + (nVx1 >> nLogxRatioUV), (workarea.y[1] << 2) + (nVy1 >> nLogyRatioUV));
+
   }
 
   MV_FORCEINLINE const uint8_t* GetRefBlockV(WorkingArea& workarea, int nVx, int nVy)
   {
+    int nVx1 = (nLogxRatioUV == 1) ? nVx + 1 : nVx;
+    int nVy1 = (nLogxRatioUV == 1) ? nVy + 1 : nVy;
     return
-      (nPel == 2) ? pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <1>((workarea.x[2] << 1) + (nVx >> nLogxRatioUV), (workarea.y[2] << 1) + (nVy >> nLogyRatioUV)) :
-      (nPel == 1) ? pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <0>((workarea.x[2]) + (nVx >> nLogxRatioUV), (workarea.y[2]) + (nVy >> nLogyRatioUV)) :
-      pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <2>((workarea.x[2] << 2) + (nVx >> nLogxRatioUV), (workarea.y[2] << 2) + (nVy >> nLogyRatioUV));
+      (nPel == 2) ? pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <1>((workarea.x[2] << 1) + (nVx1 >> nLogxRatioUV), (workarea.y[2] << 1) + (nVy1 >> nLogyRatioUV)) :
+      (nPel == 1) ? pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <0>((workarea.x[2]) + (nVx1 >> nLogxRatioUV), (workarea.y[2]) + (nVy1 >> nLogyRatioUV)) :
+      pRefFrame->GetPlane(VPLANE)->GetAbsolutePointerPel <2>((workarea.x[2] << 2) + (nVx1 >> nLogxRatioUV), (workarea.y[2] << 2) + (nVy1 >> nLogyRatioUV));
   }
 
   MV_FORCEINLINE const uint8_t* GetSrcBlock(int nX, int nY)