| /* |
| * Copyright (c) 2021, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 3-Clause Clear License |
| * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear |
| * License was not distributed with this source code in the LICENSE file, you |
| * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/. 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 |
| * aomedia.org/license/patent-license/. |
| */ |
| |
| #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 |