Limit mv search range for first pass and mbgraph

Both first pass and mbgraph search use block size 16x16 for motion
estimation. This commit put a limit of motion vector range. The
effective range allows the entire 16x16 with required subpel
interpolation input to be completely outside image border, but
not any further away from image border.

Change-Id: Id70a5ed08be49e70959f064859d72adc7d775d08

vp9/encoder/vp9_firstpass.c

@@ -534,10 +534,11 @@ void vp9_first_pass(VP9_COMP *cpi) {
     recon_yoffset = (mb_row * recon_y_stride * 16);
     recon_uvoffset = (mb_row * recon_uv_stride * 8);
 
-    // Set up limit values for motion vectors to prevent them extending outside the UMV borders
-    x->mv_row_min = -((mb_row * 16) + (VP9BORDERINPIXELS - 8));
+    // Set up limit values for motion vectors to prevent them extending
+    // outside the UMV borders
+    x->mv_row_min = -((mb_row * 16) + BORDER_MV_PIXELS_B16);
     x->mv_row_max = ((cm->mb_rows - 1 - mb_row) * 16)
-                    + (VP9BORDERINPIXELS - 8);
+                    + BORDER_MV_PIXELS_B16;
 
     // for each macroblock col in image
     for (mb_col = 0; mb_col < cm->mb_cols; mb_col++) {
@@ -583,9 +584,9 @@ void vp9_first_pass(VP9_COMP *cpi) {
       intra_error += (int64_t)this_error;
 
       // Set up limit values for motion vectors to prevent them extending outside the UMV borders
-      x->mv_col_min = -((mb_col * 16) + (VP9BORDERINPIXELS - 8));
+      x->mv_col_min = -((mb_col * 16) + BORDER_MV_PIXELS_B16);
       x->mv_col_max = ((cm->mb_cols - 1 - mb_col) * 16)
-                      + (VP9BORDERINPIXELS - 8);
+                      + BORDER_MV_PIXELS_B16;
 
       // Other than for the first frame do a motion search
       if (cm->current_video_frame > 0) {

vp9/encoder/vp9_mbgraph.c

@@ -10,14 +10,17 @@
 
 #include <limits.h>
 
-#include <vpx_mem/vpx_mem.h>
-#include <vp9/encoder/vp9_encodeintra.h>
-#include <vp9/encoder/vp9_rdopt.h>
-#include <vp9/common/vp9_blockd.h>
-#include <vp9/common/vp9_reconinter.h>
-#include <vp9/common/vp9_reconintra.h>
-#include <vp9/common/vp9_systemdependent.h>
-#include <vp9/encoder/vp9_segmentation.h>
+#include "vpx_mem/vpx_mem.h"
+#include "vp9/encoder/vp9_encodeintra.h"
+#include "vp9/encoder/vp9_rdopt.h"
+#include "vp9/encoder/vp9_segmentation.h"
+#include "vp9/encoder/vp9_mcomp.h"
+#include "vp9/common/vp9_blockd.h"
+#include "vp9/common/vp9_reconinter.h"
+#include "vp9/common/vp9_reconintra.h"
+#include "vp9/common/vp9_systemdependent.h"
+
+
 
 static unsigned int do_16x16_motion_iteration(VP9_COMP *cpi,
                                               int_mv *ref_mv,
@@ -246,9 +249,8 @@ static void update_mbgraph_frame_stats(VP9_COMP *cpi,
   // Set up limit values for motion vectors to prevent them extending outside the UMV borders
   arf_top_mv.as_int = 0;
   gld_top_mv.as_int = 0;
-  x->mv_row_min     = -(VP9BORDERINPIXELS - 8 - VP9_INTERP_EXTEND);
-  x->mv_row_max     = (cm->mb_rows - 1) * 8 + VP9BORDERINPIXELS
-                      - 8 - VP9_INTERP_EXTEND;
+  x->mv_row_min     = -BORDER_MV_PIXELS_B16;
+  x->mv_row_max     = (cm->mb_rows - 1) * 8 + BORDER_MV_PIXELS_B16;
   xd->up_available  = 0;
   xd->plane[0].dst.stride  = buf->y_stride;
   xd->plane[0].pre[0].stride  = buf->y_stride;
@@ -267,9 +269,8 @@ static void update_mbgraph_frame_stats(VP9_COMP *cpi,
     // Set up limit values for motion vectors to prevent them extending outside the UMV borders
     arf_left_mv.as_int = arf_top_mv.as_int;
     gld_left_mv.as_int = gld_top_mv.as_int;
-    x->mv_col_min      = -(VP9BORDERINPIXELS - 8 - VP9_INTERP_EXTEND);
-    x->mv_col_max      = (cm->mb_cols - 1) * 8 + VP9BORDERINPIXELS
-                         - 8 - VP9_INTERP_EXTEND;
+    x->mv_col_min      = -BORDER_MV_PIXELS_B16;
+    x->mv_col_max      = (cm->mb_cols - 1) * 8 + BORDER_MV_PIXELS_B16;
     xd->left_available = 0;
 
     for (mb_col = 0; mb_col < cm->mb_cols; mb_col++) {

vp9/encoder/vp9_mcomp.h

@@ -22,6 +22,10 @@
 #define MAX_FULL_PEL_VAL ((1 << (MAX_MVSEARCH_STEPS)) - 1)
 // Maximum size of the first step in full pel units
 #define MAX_FIRST_STEP (1 << (MAX_MVSEARCH_STEPS-1))
+// Allowed motion vector pixel distance outside image border
+// for Block_16x16
+#define BORDER_MV_PIXELS_B16 (16 + VP9_INTERP_EXTEND)
+
 
 void vp9_clamp_mv_min_max(MACROBLOCK *x, MV *mv);
 int vp9_mv_bit_cost(const MV *mv, const MV *ref,