Proposed changes to intrabc valid source area

The horizontal delay is specified in pixels to work for SB64 and SB128.
The wavefront gradient is changed so the above block is available.

Change-Id: I24cc426bded6904925930f6d431f5737070f9e17

av1/common/mvref_common.h

@@ -451,8 +451,9 @@ static INLINE void av1_find_ref_dv(int_mv *ref_dv, int mi_row, int mi_col) {
   }
 }
 
-#define INTRABC_DELAY 0   // Writing back delay in units of super-block.
-#define USE_WAVE_FRONT 0  // Use only top left area of frame for reference.
+#define INTRABC_DELAY_PIXELS 256  //  Delay of 256 pixels
+#define INTRABC_DELAY_SB64 (INTRABC_DELAY_PIXELS / 64)
+#define USE_WAVE_FRONT 1  // Use only top left area of frame for reference.
 static INLINE int av1_is_dv_valid(const MV dv, const TileInfo *const tile,
                                   int mi_row, int mi_col, BLOCK_SIZE bsize,
                                   int mib_size_log2) {
@@ -482,19 +483,20 @@ static INLINE int av1_is_dv_valid(const MV dv, const TileInfo *const tile,
   // constraints to facilitate HW decoder.
   const int max_mib_size = 1 << mib_size_log2;
   const int active_sb_row = mi_row >> mib_size_log2;
-  const int active_sb_col = mi_col >> mib_size_log2;
+  const int active_64_col = (mi_col * MI_SIZE) >> 6;
   const int sb_size = max_mib_size * MI_SIZE;
   const int src_sb_row = ((src_bottom_edge >> 3) - 1) / sb_size;
-  const int src_sb_col = ((src_right_edge >> 3) - 1) / sb_size;
+  const int src_64_col = ((src_right_edge >> 3) - 1) >> 6;
 #if USE_WAVE_FRONT
+  const int gradient = 1 + INTRABC_DELAY_SB64 + (sb_size > 64);
+  const int wf_offset = gradient * (active_sb_row - src_sb_row);
   if (src_sb_row > active_sb_row ||
-      src_sb_col >=
-          active_sb_col - INTRABC_DELAY + 2 * (active_sb_row - src_sb_row))
+      src_64_col >= active_64_col - INTRABC_DELAY_SB64 + wf_offset)
     return 0;
 #else
   if (src_sb_row > active_sb_row ||
       (src_sb_row == active_sb_row &&
-       src_sb_col >= active_sb_col - INTRABC_DELAY))
+       src_64_col >= active_64_col - INTRABC_DELAY_SB64))
     return 0;
 #endif
   return 1;