[x265] [PATCH] motion: fix overflow in mvcost() check failure

[Divya Manivannan]

# HG changeset patch
# User Divya Manivannan <divya at multicorewareinc.com>
# Date 1435933202 -19800
#      Fri Jul 03 19:50:02 2015 +0530
# Node ID 5a28e41404c776a0f8f81c301cbb7c0426857624
# Parent  f3571dc7b077e2de084f5118c6f6a9316f40f54a
motion: fix overflow in mvcost() check failure.

mvcost() funtion always truncate the value to 16 bits but there is a possiblity
of overflow in the mvcost() check failure condition given.

This check can be done in the cost calculation (s_costs) initially andso it is
removed here.

diff -r f3571dc7b077 -r 5a28e41404c7 source/encoder/motion.cpp
--- a/source/encoder/motion.cpp	Wed Jul 01 14:36:18 2015 +0530
+++ b/source/encoder/motion.cpp	Fri Jul 03 19:50:02 2015 +0530
@@ -234,14 +234,9 @@
                pix_base + (m1x) + (m1y) * stride, \
                pix_base + (m2x) + (m2y) * stride, \
                stride, costs); \
-        const uint16_t *base_mvx = &m_cost_mvx[(bmv.x + (m0x)) << 2]; \
-        const uint16_t *base_mvy = &m_cost_mvy[(bmv.y + (m0y)) << 2]; \
-        X265_CHECK(mvcost((bmv + MV(m0x, m0y)) << 2) == (base_mvx[((m0x) - (m0x)) << 2] + base_mvy[((m0y) - (m0y)) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((bmv + MV(m1x, m1y)) << 2) == (base_mvx[((m1x) - (m0x)) << 2] + base_mvy[((m1y) - (m0y)) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((bmv + MV(m2x, m2y)) << 2) == (base_mvx[((m2x) - (m0x)) << 2] + base_mvy[((m2y) - (m0y)) << 2]), "mvcost() check failure\n"); \
-        (costs)[0] += (base_mvx[((m0x) - (m0x)) << 2] + base_mvy[((m0y) - (m0y)) << 2]); \
-        (costs)[1] += (base_mvx[((m1x) - (m0x)) << 2] + base_mvy[((m1y) - (m0y)) << 2]); \
-        (costs)[2] += (base_mvx[((m2x) - (m0x)) << 2] + base_mvy[((m2y) - (m0y)) << 2]); \
+        (costs)[0] += mvcost((bmv + MV(m0x, m0y)) << 2); \
+        (costs)[1] += mvcost((bmv + MV(m1x, m1y)) << 2); \
+        (costs)[2] += mvcost((bmv + MV(m2x, m2y)) << 2); \
     }
 
 #define COST_MV_PT_DIST_X4(m0x, m0y, p0, d0, m1x, m1y, p1, d1, m2x, m2y, p2, d2, m3x, m3y, p3, d3) \
@@ -271,16 +266,10 @@
                pix_base + (m2x) + (m2y) * stride, \
                pix_base + (m3x) + (m3y) * stride, \
                stride, costs); \
-        const uint16_t *base_mvx = &m_cost_mvx[(omv.x << 2)]; \
-        const uint16_t *base_mvy = &m_cost_mvy[(omv.y << 2)]; \
-        X265_CHECK(mvcost((omv + MV(m0x, m0y)) << 2) == (base_mvx[(m0x) << 2] + base_mvy[(m0y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((omv + MV(m1x, m1y)) << 2) == (base_mvx[(m1x) << 2] + base_mvy[(m1y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((omv + MV(m2x, m2y)) << 2) == (base_mvx[(m2x) << 2] + base_mvy[(m2y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((omv + MV(m3x, m3y)) << 2) == (base_mvx[(m3x) << 2] + base_mvy[(m3y) << 2]), "mvcost() check failure\n"); \
-        costs[0] += (base_mvx[(m0x) << 2] + base_mvy[(m0y) << 2]); \
-        costs[1] += (base_mvx[(m1x) << 2] + base_mvy[(m1y) << 2]); \
-        costs[2] += (base_mvx[(m2x) << 2] + base_mvy[(m2y) << 2]); \
-        costs[3] += (base_mvx[(m3x) << 2] + base_mvy[(m3y) << 2]); \
+        costs[0] += mvcost((omv + MV(m0x, m0y)) << 2); \
+        costs[1] += mvcost((omv + MV(m1x, m1y)) << 2); \
+        costs[2] += mvcost((omv + MV(m2x, m2y)) << 2); \
+        costs[3] += mvcost((omv + MV(m3x, m3y)) << 2); \
         COPY2_IF_LT(bcost, costs[0], bmv, omv + MV(m0x, m0y)); \
         COPY2_IF_LT(bcost, costs[1], bmv, omv + MV(m1x, m1y)); \
         COPY2_IF_LT(bcost, costs[2], bmv, omv + MV(m2x, m2y)); \
@@ -296,17 +285,10 @@
                pix_base + (m2x) + (m2y) * stride, \
                pix_base + (m3x) + (m3y) * stride, \
                stride, costs); \
-        /* TODO: use restrict keyword in ICL */ \
-        const uint16_t *base_mvx = &m_cost_mvx[(bmv.x << 2)]; \
-        const uint16_t *base_mvy = &m_cost_mvy[(bmv.y << 2)]; \
-        X265_CHECK(mvcost((bmv + MV(m0x, m0y)) << 2) == (base_mvx[(m0x) << 2] + base_mvy[(m0y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((bmv + MV(m1x, m1y)) << 2) == (base_mvx[(m1x) << 2] + base_mvy[(m1y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((bmv + MV(m2x, m2y)) << 2) == (base_mvx[(m2x) << 2] + base_mvy[(m2y) << 2]), "mvcost() check failure\n"); \
-        X265_CHECK(mvcost((bmv + MV(m3x, m3y)) << 2) == (base_mvx[(m3x) << 2] + base_mvy[(m3y) << 2]), "mvcost() check failure\n"); \
-        (costs)[0] += (base_mvx[(m0x) << 2] + base_mvy[(m0y) << 2]); \
-        (costs)[1] += (base_mvx[(m1x) << 2] + base_mvy[(m1y) << 2]); \
-        (costs)[2] += (base_mvx[(m2x) << 2] + base_mvy[(m2y) << 2]); \
-        (costs)[3] += (base_mvx[(m3x) << 2] + base_mvy[(m3y) << 2]); \
+        (costs)[0] += mvcost((bmv + MV(m0x, m0y)) << 2); \
+        (costs)[1] += mvcost((bmv + MV(m1x, m1y)) << 2); \
+        (costs)[2] += mvcost((bmv + MV(m2x, m2y)) << 2); \
+        (costs)[3] += mvcost((bmv + MV(m3x, m3y)) << 2); \
     }
 
 #define DIA1_ITER(mx, my) \