Index: source/Lib/TLibEncoder/TEncSlice.cpp
===================================================================
--- source/Lib/TLibEncoder/TEncSlice.cpp	(revision 2966)
+++ source/Lib/TLibEncoder/TEncSlice.cpp	(working copy)
@@ -193,7 +193,9 @@
   // depth computation based on GOP size
   Int depth;
   {
-    Int poc = rpcSlice->getPOC()%m_pcCfg->getGOPSize();
+    Int poc=rpcSlice->getPOC();
+    if (isField) poc/=2;
+    poc = poc%m_pcCfg->getGOPSize();
     if ( poc == 0 )
     {
       depth = 0;
@@ -217,7 +219,9 @@
       }
     }
   }
-  
+
+  if (isField && depth>0) depth-=1;
+
   // slice type
   SliceType eSliceType;
   
