Bug fix in motion vector limit calculation

Motion vector limits are calculated using right shifts, which
could give wrong results for negative numbers. James Berry's
test on one clip showed encoder produced some artifacts. This
change fixed that.

Change-Id: I035fc02280b10455b7f6eb388f7c2e33b796b018

diff --git a/vp8/encoder/mcomp.c b/vp8/encoder/mcomp.c
index 4169488..6f314a3 100644 (file)
--- a/vp8/encoder/mcomp.c
+++ b/vp8/encoder/mcomp.c
@@ -286,8 +286,8 @@ int vp8_find_best_sub_pixel_step_iteratively(MACROBLOCK *x, BLOCK *b, BLOCKD *d,
     bestmv->as_mv.row = br << 1;
     bestmv->as_mv.col = bc << 1;
 
-    if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > MAX_FULL_PEL_VAL) ||
-        (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > MAX_FULL_PEL_VAL))
+    if ((abs(bestmv->as_mv.col - ref_mv->as_mv.col) > (MAX_FULL_PEL_VAL<<3)) ||
+        (abs(bestmv->as_mv.row - ref_mv->as_mv.row) > (MAX_FULL_PEL_VAL<<3)))
         return INT_MAX;
 
     return besterr;

diff --git a/vp8/encoder/mcomp.h b/vp8/encoder/mcomp.h
index 44ed055..416c4d5 100644 (file)
--- a/vp8/encoder/mcomp.h
+++ b/vp8/encoder/mcomp.h
@@ -22,7 +22,7 @@ extern void accum_mv_refs(MB_PREDICTION_MODE, const int near_mv_ref_cts[4]);
 
 
 #define MAX_MVSEARCH_STEPS 8                                    // The maximum number of steps in a step search given the largest allowed initial step
-#define MAX_FULL_PEL_VAL ((1 << (MAX_MVSEARCH_STEPS+3)) - 8)    // Max full pel mv specified in 1/8 pel units
+#define MAX_FULL_PEL_VAL ((1 << (MAX_MVSEARCH_STEPS)) - 1)      // Max full pel mv specified in 1 pel units
 #define MAX_FIRST_STEP (1 << (MAX_MVSEARCH_STEPS-1))            // Maximum size of the first step in full pel units
 
 extern void print_mode_context(void);

diff --git a/vp8/encoder/pickinter.c b/vp8/encoder/pickinter.c
index b60d241..6c73511 100644 (file)
--- a/vp8/encoder/pickinter.c
+++ b/vp8/encoder/pickinter.c
@@ -588,10 +588,10 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset,
 
             /* adjust mvp to make sure it is within MV range */
             vp8_clamp_mv(&mvp,
-                         best_ref_mv.as_mv.col - MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.col + MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.row - MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.row + MAX_FULL_PEL_VAL);
+                         best_ref_mv.as_mv.col - (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.col + (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.row - (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.row + (MAX_FULL_PEL_VAL<<3));
         }
 
         switch (this_mode)
@@ -681,10 +681,14 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset,
                 mvp.as_int = best_ref_mv.as_int;
             }
 
-            col_min = (best_ref_mv.as_mv.col - MAX_FULL_PEL_VAL) >>3;
-            col_max = (best_ref_mv.as_mv.col + MAX_FULL_PEL_VAL) >>3;
-            row_min = (best_ref_mv.as_mv.row - MAX_FULL_PEL_VAL) >>3;
-            row_max = (best_ref_mv.as_mv.row + MAX_FULL_PEL_VAL) >>3;
+            col_min = (best_ref_mv.as_mv.col < 0)?(-((abs(best_ref_mv.as_mv.col))>>3) - MAX_FULL_PEL_VAL)
+                                                 :((best_ref_mv.as_mv.col>>3) - MAX_FULL_PEL_VAL);
+            col_max = (best_ref_mv.as_mv.col < 0)?(-((abs(best_ref_mv.as_mv.col))>>3) + MAX_FULL_PEL_VAL)
+                                                 :((best_ref_mv.as_mv.col>>3) + MAX_FULL_PEL_VAL);
+            row_min = (best_ref_mv.as_mv.row < 0)?(-((abs(best_ref_mv.as_mv.row))>>3) - MAX_FULL_PEL_VAL)
+                                                 :((best_ref_mv.as_mv.row>>3) - MAX_FULL_PEL_VAL);
+            row_max = (best_ref_mv.as_mv.row < 0)?(-((abs(best_ref_mv.as_mv.row))>>3) + MAX_FULL_PEL_VAL)
+                                                 :((best_ref_mv.as_mv.row>>3) + MAX_FULL_PEL_VAL);
 
             // Get intersection of UMV window and valid MV window to reduce # of checks in diamond search.
             if (x->mv_col_min < col_min )

diff --git a/vp8/encoder/rdopt.c b/vp8/encoder/rdopt.c
index e035905..fa5bb07 100644 (file)
--- a/vp8/encoder/rdopt.c
+++ b/vp8/encoder/rdopt.c
@@ -1330,10 +1330,14 @@ static int vp8_rd_pick_best_mbsegmentation(VP8_COMP *cpi, MACROBLOCK *x,
 
         if (bsi.segment_rd < best_rd)
         {
-            int col_min = (best_ref_mv->as_mv.col - MAX_FULL_PEL_VAL) >>3;
-            int col_max = (best_ref_mv->as_mv.col + MAX_FULL_PEL_VAL) >>3;
-            int row_min = (best_ref_mv->as_mv.row - MAX_FULL_PEL_VAL) >>3;
-            int row_max = (best_ref_mv->as_mv.row + MAX_FULL_PEL_VAL) >>3;
+            int col_min = (best_ref_mv->as_mv.col < 0)?(-((abs(best_ref_mv->as_mv.col))>>3) - MAX_FULL_PEL_VAL)
+                                                      :((best_ref_mv->as_mv.col>>3) - MAX_FULL_PEL_VAL);
+            int col_max = (best_ref_mv->as_mv.col < 0)?(-((abs(best_ref_mv->as_mv.col))>>3) + MAX_FULL_PEL_VAL)
+                                                      :((best_ref_mv->as_mv.col>>3) + MAX_FULL_PEL_VAL);
+            int row_min = (best_ref_mv->as_mv.row < 0)?(-((abs(best_ref_mv->as_mv.row))>>3) - MAX_FULL_PEL_VAL)
+                                                      :((best_ref_mv->as_mv.row>>3) - MAX_FULL_PEL_VAL);
+            int row_max = (best_ref_mv->as_mv.row < 0)?(-((abs(best_ref_mv->as_mv.row))>>3) + MAX_FULL_PEL_VAL)
+                                                      :((best_ref_mv->as_mv.row>>3) + MAX_FULL_PEL_VAL);
 
             int tmp_col_min = x->mv_col_min;
             int tmp_col_max = x->mv_col_max;
@@ -1876,10 +1880,10 @@ void vp8_rd_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int
 
             /* adjust mvp to make sure it is within MV range */
             vp8_clamp_mv(&mvp,
-                         best_ref_mv.as_mv.col - MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.col + MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.row - MAX_FULL_PEL_VAL,
-                         best_ref_mv.as_mv.row + MAX_FULL_PEL_VAL);
+                         best_ref_mv.as_mv.col - (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.col + (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.row - (MAX_FULL_PEL_VAL<<3),
+                         best_ref_mv.as_mv.row + (MAX_FULL_PEL_VAL<<3));
         }
 
         // Check to see if the testing frequency for this mode is at its max
@@ -2011,10 +2015,14 @@ void vp8_rd_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int
 
             int sadpb = x->sadperbit16;
 
-            int col_min = (best_ref_mv.as_mv.col - MAX_FULL_PEL_VAL) >>3;
-            int col_max = (best_ref_mv.as_mv.col + MAX_FULL_PEL_VAL) >>3;
-            int row_min = (best_ref_mv.as_mv.row - MAX_FULL_PEL_VAL) >>3;
-            int row_max = (best_ref_mv.as_mv.row + MAX_FULL_PEL_VAL) >>3;
+            int col_min = (best_ref_mv.as_mv.col < 0)?(-((abs(best_ref_mv.as_mv.col))>>3) - MAX_FULL_PEL_VAL)
+                                                     :((best_ref_mv.as_mv.col>>3) - MAX_FULL_PEL_VAL);
+            int col_max = (best_ref_mv.as_mv.col < 0)?(-((abs(best_ref_mv.as_mv.col))>>3) + MAX_FULL_PEL_VAL)
+                                                     :((best_ref_mv.as_mv.col>>3) + MAX_FULL_PEL_VAL);
+            int row_min = (best_ref_mv.as_mv.row < 0)?(-((abs(best_ref_mv.as_mv.row))>>3) - MAX_FULL_PEL_VAL)
+                                                     :((best_ref_mv.as_mv.row>>3) - MAX_FULL_PEL_VAL);
+            int row_max = (best_ref_mv.as_mv.row < 0)?(-((abs(best_ref_mv.as_mv.row))>>3) + MAX_FULL_PEL_VAL)
+                                                     :((best_ref_mv.as_mv.row>>3) + MAX_FULL_PEL_VAL);
 
             int tmp_col_min = x->mv_col_min;
             int tmp_col_max = x->mv_col_max;