+#define BOUNDARY_LEFT_SLICE (1 << 0)
+#define BOUNDARY_LEFT_TILE (1 << 1)
+#define BOUNDARY_UPPER_SLICE (1 << 2)
+#define BOUNDARY_UPPER_TILE (1 << 3)
+ /* properties of the boundary of the current CTB for the purposes
+ * of the deblocking filter */
+ int boundary_flags;