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-rw-r--r--third_party/aom/av1/encoder/palette.c277
1 files changed, 277 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/palette.c b/third_party/aom/av1/encoder/palette.c
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+++ b/third_party/aom/av1/encoder/palette.c
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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 <math.h>
+#include <stdlib.h>
+
+#include "av1/encoder/cost.h"
+#include "av1/encoder/palette.h"
+
+static float calc_dist(const float *p1, const float *p2, int dim) {
+ float dist = 0;
+ int i;
+ for (i = 0; i < dim; ++i) {
+ const float diff = p1[i] - p2[i];
+ dist += diff * diff;
+ }
+ return dist;
+}
+
+void av1_calc_indices(const float *data, const float *centroids,
+ uint8_t *indices, int n, int k, int dim) {
+ int i, j;
+ for (i = 0; i < n; ++i) {
+ float min_dist = calc_dist(data + i * dim, centroids, dim);
+ indices[i] = 0;
+ for (j = 1; j < k; ++j) {
+ const float this_dist =
+ calc_dist(data + i * dim, centroids + j * dim, dim);
+ if (this_dist < min_dist) {
+ min_dist = this_dist;
+ indices[i] = j;
+ }
+ }
+ }
+}
+
+// Generate a random number in the range [0, 32768).
+static unsigned int lcg_rand16(unsigned int *state) {
+ *state = (unsigned int)(*state * 1103515245ULL + 12345);
+ return *state / 65536 % 32768;
+}
+
+static void calc_centroids(const float *data, float *centroids,
+ const uint8_t *indices, int n, int k, int dim) {
+ int i, j, index;
+ int count[PALETTE_MAX_SIZE];
+ unsigned int rand_state = (unsigned int)data[0];
+
+ assert(n <= 32768);
+
+ memset(count, 0, sizeof(count[0]) * k);
+ memset(centroids, 0, sizeof(centroids[0]) * k * dim);
+
+ for (i = 0; i < n; ++i) {
+ index = indices[i];
+ assert(index < k);
+ ++count[index];
+ for (j = 0; j < dim; ++j) {
+ centroids[index * dim + j] += data[i * dim + j];
+ }
+ }
+
+ for (i = 0; i < k; ++i) {
+ if (count[i] == 0) {
+ memcpy(centroids + i * dim, data + (lcg_rand16(&rand_state) % n) * dim,
+ sizeof(centroids[0]) * dim);
+ } else {
+ const float norm = 1.0f / count[i];
+ for (j = 0; j < dim; ++j) centroids[i * dim + j] *= norm;
+ }
+ }
+
+ // Round to nearest integers.
+ for (i = 0; i < k * dim; ++i) {
+ centroids[i] = roundf(centroids[i]);
+ }
+}
+
+static float calc_total_dist(const float *data, const float *centroids,
+ const uint8_t *indices, int n, int k, int dim) {
+ float dist = 0;
+ int i;
+ (void)k;
+
+ for (i = 0; i < n; ++i)
+ dist += calc_dist(data + i * dim, centroids + indices[i] * dim, dim);
+
+ return dist;
+}
+
+void av1_k_means(const float *data, float *centroids, uint8_t *indices, int n,
+ int k, int dim, int max_itr) {
+ int i;
+ float this_dist;
+ float pre_centroids[2 * PALETTE_MAX_SIZE];
+ uint8_t pre_indices[MAX_SB_SQUARE];
+
+ av1_calc_indices(data, centroids, indices, n, k, dim);
+ this_dist = calc_total_dist(data, centroids, indices, n, k, dim);
+
+ for (i = 0; i < max_itr; ++i) {
+ const float pre_dist = this_dist;
+ memcpy(pre_centroids, centroids, sizeof(pre_centroids[0]) * k * dim);
+ memcpy(pre_indices, indices, sizeof(pre_indices[0]) * n);
+
+ calc_centroids(data, centroids, indices, n, k, dim);
+ av1_calc_indices(data, centroids, indices, n, k, dim);
+ this_dist = calc_total_dist(data, centroids, indices, n, k, dim);
+
+ if (this_dist > pre_dist) {
+ memcpy(centroids, pre_centroids, sizeof(pre_centroids[0]) * k * dim);
+ memcpy(indices, pre_indices, sizeof(pre_indices[0]) * n);
+ break;
+ }
+ if (!memcmp(centroids, pre_centroids, sizeof(pre_centroids[0]) * k * dim))
+ break;
+ }
+}
+
+static int float_comparer(const void *a, const void *b) {
+ const float fa = *(const float *)a;
+ const float fb = *(const float *)b;
+ return (fa > fb) - (fa < fb);
+}
+
+int av1_remove_duplicates(float *centroids, int num_centroids) {
+ int num_unique; // number of unique centroids
+ int i;
+ qsort(centroids, num_centroids, sizeof(*centroids), float_comparer);
+ // Remove duplicates.
+ num_unique = 1;
+ for (i = 1; i < num_centroids; ++i) {
+ if (centroids[i] != centroids[i - 1]) { // found a new unique centroid
+ centroids[num_unique++] = centroids[i];
+ }
+ }
+ return num_unique;
+}
+
+int av1_count_colors(const uint8_t *src, int stride, int rows, int cols) {
+ int n = 0, r, c, i, val_count[256];
+ uint8_t val;
+ memset(val_count, 0, sizeof(val_count));
+
+ for (r = 0; r < rows; ++r) {
+ for (c = 0; c < cols; ++c) {
+ val = src[r * stride + c];
+ ++val_count[val];
+ }
+ }
+
+ for (i = 0; i < 256; ++i) {
+ if (val_count[i]) {
+ ++n;
+ }
+ }
+
+ return n;
+}
+
+#if CONFIG_PALETTE_DELTA_ENCODING
+int av1_get_palette_delta_bits_y(const PALETTE_MODE_INFO *const pmi,
+ int bit_depth, int *min_bits) {
+ const int n = pmi->palette_size[0];
+ int max_d = 0, i;
+ *min_bits = bit_depth - 3;
+ for (i = 1; i < n; ++i) {
+ const int delta = pmi->palette_colors[i] - pmi->palette_colors[i - 1];
+ assert(delta > 0);
+ if (delta > max_d) max_d = delta;
+ }
+ return AOMMAX(av1_ceil_log2(max_d), *min_bits);
+}
+
+int av1_get_palette_delta_bits_u(const PALETTE_MODE_INFO *const pmi,
+ int bit_depth, int *min_bits) {
+ const int n = pmi->palette_size[1];
+ int max_d = 0, i;
+ *min_bits = bit_depth - 3;
+ for (i = 1; i < n; ++i) {
+ const int delta = pmi->palette_colors[PALETTE_MAX_SIZE + i] -
+ pmi->palette_colors[PALETTE_MAX_SIZE + i - 1];
+ assert(delta >= 0);
+ if (delta > max_d) max_d = delta;
+ }
+ return AOMMAX(av1_ceil_log2(max_d + 1), *min_bits);
+}
+
+int av1_get_palette_delta_bits_v(const PALETTE_MODE_INFO *const pmi,
+ int bit_depth, int *zero_count,
+ int *min_bits) {
+ const int n = pmi->palette_size[1];
+ const int max_val = 1 << bit_depth;
+ int max_d = 0, i;
+ *min_bits = bit_depth - 4;
+ *zero_count = 0;
+ for (i = 1; i < n; ++i) {
+ const int delta = pmi->palette_colors[2 * PALETTE_MAX_SIZE + i] -
+ pmi->palette_colors[2 * PALETTE_MAX_SIZE + i - 1];
+ const int v = abs(delta);
+ const int d = AOMMIN(v, max_val - v);
+ if (d > max_d) max_d = d;
+ if (d == 0) ++(*zero_count);
+ }
+ return AOMMAX(av1_ceil_log2(max_d + 1), *min_bits);
+}
+#endif // CONFIG_PALETTE_DELTA_ENCODING
+
+int av1_palette_color_cost_y(const PALETTE_MODE_INFO *const pmi,
+ int bit_depth) {
+ const int n = pmi->palette_size[0];
+#if CONFIG_PALETTE_DELTA_ENCODING
+ int min_bits = 0;
+ const int bits = av1_get_palette_delta_bits_y(pmi, bit_depth, &min_bits);
+ return av1_cost_bit(128, 0) * (2 + bit_depth + bits * (n - 1));
+#else
+ return bit_depth * n * av1_cost_bit(128, 0);
+#endif // CONFIG_PALETTE_DELTA_ENCODING
+}
+
+int av1_palette_color_cost_uv(const PALETTE_MODE_INFO *const pmi,
+ int bit_depth) {
+ const int n = pmi->palette_size[1];
+#if CONFIG_PALETTE_DELTA_ENCODING
+ int cost = 0;
+ // U channel palette color cost.
+ int min_bits_u = 0;
+ const int bits_u = av1_get_palette_delta_bits_u(pmi, bit_depth, &min_bits_u);
+ cost += av1_cost_bit(128, 0) * (2 + bit_depth + bits_u * (n - 1));
+ // V channel palette color cost.
+ int zero_count = 0, min_bits_v = 0;
+ const int bits_v =
+ av1_get_palette_delta_bits_v(pmi, bit_depth, &zero_count, &min_bits_v);
+ const int bits_using_delta =
+ 2 + bit_depth + (bits_v + 1) * (n - 1) - zero_count;
+ const int bits_using_raw = bit_depth * n;
+ cost += av1_cost_bit(128, 0) * (1 + AOMMIN(bits_using_delta, bits_using_raw));
+ return cost;
+#else
+ return 2 * bit_depth * n * av1_cost_bit(128, 0);
+#endif // CONFIG_PALETTE_DELTA_ENCODING
+}
+
+#if CONFIG_HIGHBITDEPTH
+int av1_count_colors_highbd(const uint8_t *src8, int stride, int rows, int cols,
+ int bit_depth) {
+ int n = 0, r, c, i;
+ uint16_t val;
+ uint16_t *src = CONVERT_TO_SHORTPTR(src8);
+ int val_count[1 << 12];
+
+ assert(bit_depth <= 12);
+ memset(val_count, 0, (1 << 12) * sizeof(val_count[0]));
+ for (r = 0; r < rows; ++r) {
+ for (c = 0; c < cols; ++c) {
+ val = src[r * stride + c];
+ ++val_count[val];
+ }
+ }
+
+ for (i = 0; i < (1 << bit_depth); ++i) {
+ if (val_count[i]) {
+ ++n;
+ }
+ }
+
+ return n;
+}
+#endif // CONFIG_HIGHBITDEPTH
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