shithub: libvpx

Info  •  Files  •  Log  •  Branches

VP8: Fix out of range index for mvcost.

Clamp index between 0 and MVvals.

Bit exact for speed -8, -6 and -4 on RTC set.

BUG=b/72510002

Change-Id: I61bdb02a0924e157b3c1980f74fbbfe5ce51bc44

--- a/vp8/encoder/mcomp.c

+++ b/vp8/encoder/mcomp.c

@@ -34,10 +34,11 @@

    * NEAREST for subsequent blocks. The "Weight" parameter allows, to a

    * limited extent, for some account to be taken of these factors.

    */

-  return ((mvcost[0][(mv->as_mv.row - ref->as_mv.row) >> 1] +

-           mvcost[1][(mv->as_mv.col - ref->as_mv.col) >> 1]) *

-          Weight) >>

-         7;

+  const int mv_idx_row =

+      clamp((mv->as_mv.row - ref->as_mv.row) >> 1, 0, MVvals);

+  const int mv_idx_col =

+      clamp((mv->as_mv.col - ref->as_mv.col) >> 1, 0, MVvals);

+  return ((mvcost[0][mv_idx_row] + mvcost[1][mv_idx_col]) * Weight) >> 7;

 }

 static int mv_err_cost(int_mv *mv, int_mv *ref, int *mvcost[2],

@@ -44,9 +45,11 @@

                        int error_per_bit) {

   /* Ignore mv costing if mvcost is NULL */

   if (mvcost) {

-    return ((mvcost[0][(mv->as_mv.row - ref->as_mv.row) >> 1] +

-             mvcost[1][(mv->as_mv.col - ref->as_mv.col) >> 1]) *

-                error_per_bit +

+    const int mv_idx_row =

+        clamp((mv->as_mv.row - ref->as_mv.row) >> 1, 0, MVvals);

+    const int mv_idx_col =

+        clamp((mv->as_mv.col - ref->as_mv.col) >> 1, 0, MVvals);

+    return ((mvcost[0][mv_idx_row] + mvcost[1][mv_idx_col]) * error_per_bit +

             128) >>

            8;

   }