Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

third_party/aom/aom_dsp/sum_squares.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <assert.h>
+
+#include "./aom_dsp_rtcd.h"
+
+uint64_t aom_sum_squares_2d_i16_c(const int16_t *src, int src_stride, int width,
+                                  int height) {
+  int r, c;
+  uint64_t ss = 0;
+
+  for (r = 0; r < height; r++) {
+    for (c = 0; c < width; c++) {
+      const int16_t v = src[c];
+      ss += v * v;
+    }
+    src += src_stride;
+  }
+
+  return ss;
+}
+
+uint64_t aom_sum_squares_i16_c(const int16_t *src, uint32_t n) {
+  uint64_t ss = 0;
+  do {
+    const int16_t v = *src++;
+    ss += v * v;
+  } while (--n);
+
+  return ss;
+}