Fix crash with cb4x4 and warped-motion

BUG=aomedia:314

Change-Id: I66af7f69ca0b97b9d840918a6b9ec34708a7f4e5

av1/common/mvref_common.c

@@ -1087,6 +1087,7 @@ int findSamples(const AV1_COMMON *cm, MACROBLOCKD *xd, int mi_row, int mi_col,
       }
     }
   }
+  assert(2 * np <= SAMPLES_ARRAY_SIZE);
 
   // scan the left column
   if (left_available) {
@@ -1129,6 +1130,7 @@ int findSamples(const AV1_COMMON *cm, MACROBLOCKD *xd, int mi_row, int mi_col,
       }
     }
   }
+  assert(2 * np <= SAMPLES_ARRAY_SIZE);
 
   if (left_available && up_available) {
     int mi_row_offset = -1;
@@ -1166,6 +1168,7 @@ int findSamples(const AV1_COMMON *cm, MACROBLOCKD *xd, int mi_row, int mi_col,
       np += pixelperblock;
     }
   }
+  assert(2 * np <= SAMPLES_ARRAY_SIZE);
 
   for (i = 0; i < (mvnumber - 1); ++i) {
     if (mvasint[i] != mvasint[i + 1]) break;
@@ -1200,6 +1203,7 @@ int findSamples(const AV1_COMMON *cm, MACROBLOCKD *xd, int mi_row, int mi_col,
     }
     np += pixelperblock;
   }
+  assert(2 * np <= SAMPLES_ARRAY_SIZE);
 
   return np;
 }

av1/common/warped_motion.c

@@ -413,7 +413,7 @@ static uint8_t warp_interpolate(uint8_t *ref, int x, int y, int width,
 // [-1, 2) * WARPEDPIXEL_PREC_SHIFTS.
 // We need an extra 2 taps to fit this in, for a total of 8 taps.
 /* clang-format off */
-const int16_t warped_filter[WARPEDPIXEL_PREC_SHIFTS*3][8] = {
+const int16_t warped_filter[WARPEDPIXEL_PREC_SHIFTS * 3][8] = {
   // [-1, 0)
   { 0,   0, 128,   0,   0, 0, 0, 0 }, { 0, - 1, 128,   2, - 1, 0, 0, 0 },
   { 1, - 3, 127,   4, - 1, 0, 0, 0 }, { 1, - 4, 126,   6, - 2, 1, 0, 0 },

av1/common/warped_motion.h

@@ -25,6 +25,8 @@
 
 #define MAX_PARAMDIM 9
 #if CONFIG_WARPED_MOTION
+#define SAMPLES_PER_NEIGHBOR 4
+#define SAMPLES_ARRAY_SIZE ((2 * MAX_MIB_SIZE + 2) * SAMPLES_PER_NEIGHBOR * 2)
 #define DEFAULT_WMTYPE ROTZOOM
 #endif  // CONFIG_WARPED_MOTION
 

av1/decoder/decodemv.c

@@ -1510,7 +1510,7 @@ static void read_inter_block_mode_info(AV1Decoder *const pbi,
 #endif  // CONFIG_REF_MV && CONFIG_EXT_INTER
   int16_t mode_ctx = 0;
 #if CONFIG_WARPED_MOTION
-  double pts[144], pts_inref[144];
+  double pts[SAMPLES_ARRAY_SIZE], pts_inref[SAMPLES_ARRAY_SIZE];
 #endif  // CONFIG_WARPED_MOTION
 #if CONFIG_EC_ADAPT
   FRAME_CONTEXT *ec_ctx = xd->tile_ctx;

av1/encoder/rdopt.c

@@ -7818,7 +7818,7 @@ static int64_t handle_inter_mode(
 #endif  // CONFIG_EXT_INTER
 #endif  // CONFIG_MOTION_VAR || CONFIG_WARPED_MOTION
 #if CONFIG_WARPED_MOTION
-  double pts[144], pts_inref[144];
+  double pts[SAMPLES_ARRAY_SIZE], pts_inref[SAMPLES_ARRAY_SIZE];
 #endif  // CONFIG_WARPED_MOTION
   int64_t rd = INT64_MAX;
   BUFFER_SET orig_dst, tmp_dst;