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diff --git a/media/libaom/src/av1/encoder/k_means_template.h b/media/libaom/src/av1/encoder/k_means_template.h
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+/*
+ * 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 <stdint.h>
+#include <string.h>
+
+#include "av1/encoder/palette.h"
+#include "av1/encoder/random.h"
+
+#ifndef AV1_K_MEANS_DIM
+#error "This template requires AV1_K_MEANS_DIM to be defined"
+#endif
+
+#define RENAME_(x, y) AV1_K_MEANS_RENAME(x, y)
+#define RENAME(x) RENAME_(x, AV1_K_MEANS_DIM)
+
+static int RENAME(calc_dist)(const int *p1, const int *p2) {
+ int dist = 0;
+ for (int i = 0; i < AV1_K_MEANS_DIM; ++i) {
+ const int diff = p1[i] - p2[i];
+ dist += diff * diff;
+ }
+ return dist;
+}
+
+void RENAME(av1_calc_indices)(const int *data, const int *centroids,
+ uint8_t *indices, int n, int k) {
+ for (int i = 0; i < n; ++i) {
+ int min_dist = RENAME(calc_dist)(data + i * AV1_K_MEANS_DIM, centroids);
+ indices[i] = 0;
+ for (int j = 1; j < k; ++j) {
+ const int this_dist = RENAME(calc_dist)(data + i * AV1_K_MEANS_DIM,
+ centroids + j * AV1_K_MEANS_DIM);
+ if (this_dist < min_dist) {
+ min_dist = this_dist;
+ indices[i] = j;
+ }
+ }
+ }
+}
+
+static void RENAME(calc_centroids)(const int *data, int *centroids,
+ const uint8_t *indices, int n, int k) {
+ int i, j;
+ int count[PALETTE_MAX_SIZE] = { 0 };
+ unsigned int rand_state = (unsigned int)data[0];
+ assert(n <= 32768);
+ memset(centroids, 0, sizeof(centroids[0]) * k * AV1_K_MEANS_DIM);
+
+ for (i = 0; i < n; ++i) {
+ const int index = indices[i];
+ assert(index < k);
+ ++count[index];
+ for (j = 0; j < AV1_K_MEANS_DIM; ++j) {
+ centroids[index * AV1_K_MEANS_DIM + j] += data[i * AV1_K_MEANS_DIM + j];
+ }
+ }
+
+ for (i = 0; i < k; ++i) {
+ if (count[i] == 0) {
+ memcpy(centroids + i * AV1_K_MEANS_DIM,
+ data + (lcg_rand16(&rand_state) % n) * AV1_K_MEANS_DIM,
+ sizeof(centroids[0]) * AV1_K_MEANS_DIM);
+ } else {
+ for (j = 0; j < AV1_K_MEANS_DIM; ++j) {
+ centroids[i * AV1_K_MEANS_DIM + j] =
+ DIVIDE_AND_ROUND(centroids[i * AV1_K_MEANS_DIM + j], count[i]);
+ }
+ }
+ }
+}
+
+static int64_t RENAME(calc_total_dist)(const int *data, const int *centroids,
+ const uint8_t *indices, int n, int k) {
+ int64_t dist = 0;
+ (void)k;
+ for (int i = 0; i < n; ++i) {
+ dist += RENAME(calc_dist)(data + i * AV1_K_MEANS_DIM,
+ centroids + indices[i] * AV1_K_MEANS_DIM);
+ }
+ return dist;
+}
+
+void RENAME(av1_k_means)(const int *data, int *centroids, uint8_t *indices,
+ int n, int k, int max_itr) {
+ int pre_centroids[2 * PALETTE_MAX_SIZE];
+ uint8_t pre_indices[MAX_SB_SQUARE];
+
+ RENAME(av1_calc_indices)(data, centroids, indices, n, k);
+ int64_t this_dist = RENAME(calc_total_dist)(data, centroids, indices, n, k);
+
+ for (int i = 0; i < max_itr; ++i) {
+ const int64_t pre_dist = this_dist;
+ memcpy(pre_centroids, centroids,
+ sizeof(pre_centroids[0]) * k * AV1_K_MEANS_DIM);
+ memcpy(pre_indices, indices, sizeof(pre_indices[0]) * n);
+
+ RENAME(calc_centroids)(data, centroids, indices, n, k);
+ RENAME(av1_calc_indices)(data, centroids, indices, n, k);
+ this_dist = RENAME(calc_total_dist)(data, centroids, indices, n, k);
+
+ if (this_dist > pre_dist) {
+ memcpy(centroids, pre_centroids,
+ sizeof(pre_centroids[0]) * k * AV1_K_MEANS_DIM);
+ memcpy(indices, pre_indices, sizeof(pre_indices[0]) * n);
+ break;
+ }
+ if (!memcmp(centroids, pre_centroids,
+ sizeof(pre_centroids[0]) * k * AV1_K_MEANS_DIM))
+ break;
+ }
+}
+#undef RENAME_
+#undef RENAME