libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_idct.h

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 63 matching lines @@
 static const int cospi_31_64 = 804;
 
 //  16384 * sqrt(2) * sin(kPi/9) * 2 / 3
 static const int sinpi_1_9 = 5283;
 static const int sinpi_2_9 = 9929;
 static const int sinpi_3_9 = 13377;
 static const int sinpi_4_9 = 15212;
 
 static INLINE int dct_const_round_shift(int input) {
   int rv = ROUND_POWER_OF_TWO(input, DCT_CONST_BITS);
+#if CONFIG_COEFFICIENT_RANGE_CHECKING
+  // For valid VP9 input streams, intermediate stage coefficients should always
+  // stay within the range of a signed 16 bit integer. Coefficients can go out
+  // of this range for invalid/corrupt VP9 streams. However, strictly checking
+  // this range for every intermediate coefficient can burdensome for a decoder,
+  // therefore the following assertion is only enabled when configured with
+  // --enable-coefficient-range-checking.
+  assert(INT16_MIN <= rv);
+  assert(rv <= INT16_MAX);
+#endif
   return (int16_t)rv;
 }
 
 typedef void (*transform_1d)(const int16_t*, int16_t*);
 
 typedef struct {
   transform_1d cols, rows;  // vertical and horizontal
 } transform_2d;
 
 void vp9_iwht4x4_add(const int16_t *input, uint8_t *dest, int stride, int eob);
@@ skipping 11 matching lines @@
                     int stride, int eob);
 void vp9_iht16x16_add(TX_TYPE tx_type, const int16_t *input, uint8_t *dest,
                       int stride, int eob);
 
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // VP9_COMMON_VP9_IDCT_H_