[x265] [PATCH] lookahead: fix crash for I frame cost estimation

[deepthidevaki at multicorewareinc.com]

# HG changeset patch
# User Deepthi Devaki <deepthidevaki at multicorewareinc.com>
# Date 1379582068 -19800
# Node ID ff0875e85a0b5a5486537036152d228cc0ded15b
# Parent  eea9154229a0aa91da16b1323d7999cfcb1cd0b7
lookahead: fix crash for I frame cost estimation

diff -r eea9154229a0 -r ff0875e85a0b source/encoder/slicetype.cpp
--- a/source/encoder/slicetype.cpp	Thu Sep 19 09:17:03 2013 +0530
+++ b/source/encoder/slicetype.cpp	Thu Sep 19 14:44:28 2013 +0530
@@ -360,44 +360,46 @@
     mvmax.x = (uint16_t)((widthInCU - cux - 1) * cuSize + 8);
     mvmax.y = (uint16_t)((heightInCU - cuy - 1) * cuSize + 8);
 
-    for (int i = 0; i < 1 + bBidir; i++)
+    if (p0 != p1)
     {
-        if (!bDoSearch[i])
+        for (int i = 0; i < 1 + bBidir; i++)
         {
-            /* Use previously calculated cost */
+            if (!bDoSearch[i])
+            {
+                /* Use previously calculated cost */
+                COPY2_IF_LT(bcost, *fenc_costs[i], listused, i + 1);
+                continue;
+            }
+            int numc = 0;
+            MV mvc[4], mvp;
+            MV *fenc_mv = fenc_mvs[i];
+
+            /* Reverse-order MV prediction. */
+            mvc[0] = 0;
+            mvc[2] = 0;
+#define MVC(mv) mvc[numc++] = mv;
+            if (cux < widthInCU - 1)
+                MVC(fenc_mv[1]);
+            if (cuy < heightInCU - 1)
+            {
+                MVC(fenc_mv[widthInCU]);
+                if (cux > 0)
+                    MVC(fenc_mv[widthInCU - 1]);
+                if (cux < widthInCU - 1)
+                    MVC(fenc_mv[widthInCU + 1]);
+            }
+#undef MVC
+            if (numc <= 1)
+                mvp = mvc[0];
+            else
+            {
+                x265_median_mv(mvp, mvc[0], mvc[1], mvc[2]);
+            }
+
+            *fenc_costs[i] = me.motionEstimate(i ? fref1 : fref0, mvmin, mvmax, mvp, numc, mvc, merange, *fenc_mvs[i]);
             COPY2_IF_LT(bcost, *fenc_costs[i], listused, i + 1);
-            continue;
         }
-        int numc = 0;
-        MV mvc[4], mvp;
-        MV *fenc_mv = fenc_mvs[i];
-
-        /* Reverse-order MV prediction. */
-        mvc[0] = 0;
-        mvc[2] = 0;
-#define MVC(mv) mvc[numc++] = mv;
-        if (cux < widthInCU - 1)
-            MVC(fenc_mv[1]);
-        if (cuy < heightInCU - 1)
-        {
-            MVC(fenc_mv[widthInCU]);
-            if (cux > 0)
-                MVC(fenc_mv[widthInCU - 1]);
-            if (cux < widthInCU - 1)
-                MVC(fenc_mv[widthInCU + 1]);
-        }
-#undef MVC
-        if (numc <= 1)
-            mvp = mvc[0];
-        else
-        {
-            x265_median_mv(mvp, mvc[0], mvc[1], mvc[2]);
-        }
-
-        *fenc_costs[i] = me.motionEstimate(i ? fref1 : fref0, mvmin, mvmax, mvp, numc, mvc, merange, *fenc_mvs[i]);
-        COPY2_IF_LT(bcost, *fenc_costs[i], listused, i + 1);
     }
-
     if (!fenc->bIntraCalculated)
     {
         int nLog2SizeMinus2 = g_convertToBit[cuSize]; // partition size