libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_avg.c

 /*
  *  Copyright (c) 2014 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.
  */
 #include "vp9/common/vp9_common.h"
@@ skipping 14 matching lines @@
   for (i = 0; i < 4; ++i, s+=p)
     for (j = 0; j < 4; sum += s[j], ++j) {}
 
   return (sum + 8) >> 4;
 }
 
 // Integer projection onto row vectors.
 void vp9_int_pro_row_c(int16_t *hbuf, uint8_t const *ref,
                        const int ref_stride, const int height) {
   int idx;
+  const int norm_factor = MAX(8, height >> 1);
   for (idx = 0; idx < 16; ++idx) {
     int i;
     hbuf[idx] = 0;
     for (i = 0; i < height; ++i)
       hbuf[idx] += ref[i * ref_stride];
+    hbuf[idx] /= norm_factor;
     ++ref;
   }
 }
 
 int16_t vp9_int_pro_col_c(uint8_t const *ref, const int width) {
   int idx;
   int16_t sum = 0;
+  const int norm_factor = MAX(8, width >> 1);
   for (idx = 0; idx < width; ++idx)
     sum += ref[idx];
-  return sum;
+  return sum / norm_factor;
 }
 
-int vp9_vector_sad_c(int16_t const *ref, int16_t const *src,
-                     const int width) {
+int vp9_vector_var_c(int16_t const *ref, int16_t const *src,
+                     const int bwl) {
   int i;
-  int this_sad = 0;
-  for (i = 0; i < width; ++i)
-    this_sad += abs(ref[i] - src[i]);
-  return this_sad;
+  int width = 4 << bwl;
+  int sse = 0, mean = 0, var;
+
+  for (i = 0; i < width; ++i) {
+    int diff = ref[i] - src[i];
+    mean += diff;
+    sse += diff * diff;
+  }
+
+  var = sse - ((mean * mean) >> (bwl + 2));
+  return var;
 }
 
 #if CONFIG_VP9_HIGHBITDEPTH
 unsigned int vp9_highbd_avg_8x8_c(const uint8_t *s8, int p) {
   int i, j;
   int sum = 0;
   const uint16_t* s = CONVERT_TO_SHORTPTR(s8);
   for (i = 0; i < 8; ++i, s+=p)
     for (j = 0; j < 8; sum += s[j], ++j) {}
 
   return (sum + 32) >> 6;
 }
 
 unsigned int vp9_highbd_avg_4x4_c(const uint8_t *s8, int p) {
   int i, j;
   int sum = 0;
   const uint16_t* s = CONVERT_TO_SHORTPTR(s8);
   for (i = 0; i < 4; ++i, s+=p)
     for (j = 0; j < 4; sum += s[j], ++j) {}
 
   return (sum + 8) >> 4;
 }
 #endif  // CONFIG_VP9_HIGHBITDEPTH