text: /*
   * 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 "./clpf.h"
  #include "./av1_rtcd.h"
  #include "./cdef.h"
  #include "aom/aom_image.h"
  #include "aom_dsp/aom_dsp_common.h"
  
  int av1_clpf_sample(int X, int A, int B, int C, int D, int E, int F, int G,
                      int H, int s, unsigned int dmp) {
    int delta = 1 * constrain(A - X, s, dmp) + 3 * constrain(B - X, s, dmp) +
                1 * constrain(C - X, s, dmp) + 3 * constrain(D - X, s, dmp) +
                3 * constrain(E - X, s, dmp) + 1 * constrain(F - X, s, dmp) +
                3 * constrain(G - X, s, dmp) + 1 * constrain(H - X, s, dmp);
    return (8 + delta - (delta < 0)) >> 4;
  }
  
  int av1_clpf_hsample(int X, int A, int B, int C, int D, int s,
                       unsigned int dmp) {
    int delta = 1 * constrain(A - X, s, dmp) + 3 * constrain(B - X, s, dmp) +
                3 * constrain(C - X, s, dmp) + 1 * constrain(D - X, s, dmp);
    return (4 + delta - (delta < 0)) >> 3;
  }
  
  void aom_clpf_block_c(uint8_t *dst, const uint16_t *src, int dstride,
                        int sstride, int sizex, int sizey, unsigned int strength,
                        unsigned int damping) {
    int x, y;
  
    for (y = 0; y < sizey; y++) {
      for (x = 0; x < sizex; x++) {
        const int X = src[y * sstride + x];
        const int A = src[(y - 2) * sstride + x];
        const int B = src[(y - 1) * sstride + x];
        const int C = src[y * sstride + x - 2];
        const int D = src[y * sstride + x - 1];
        const int E = src[y * sstride + x + 1];
        const int F = src[y * sstride + x + 2];
        const int G = src[(y + 1) * sstride + x];
        const int H = src[(y + 2) * sstride + x];
        const int delta =
            av1_clpf_sample(X, A, B, C, D, E, F, G, H, strength, damping);
        dst[y * dstride + x] = X + delta;
      }
    }
  }
  
  // Identical to aom_clpf_block_c() apart from "dst".
  void aom_clpf_block_hbd_c(uint16_t *dst, const uint16_t *src, int dstride,
                            int sstride, int sizex, int sizey,
                            unsigned int strength, unsigned int damping) {
    int x, y;
  
    for (y = 0; y < sizey; y++) {
      for (x = 0; x < sizex; x++) {
        const int X = src[y * sstride + x];
        const int A = src[(y - 2) * sstride + x];
        const int B = src[(y - 1) * sstride + x];
        const int C = src[y * sstride + x - 2];
        const int D = src[y * sstride + x - 1];
        const int E = src[y * sstride + x + 1];
        const int F = src[y * sstride + x + 2];
        const int G = src[(y + 1) * sstride + x];
        const int H = src[(y + 2) * sstride + x];
        const int delta =
            av1_clpf_sample(X, A, B, C, D, E, F, G, H, strength, damping);
        dst[y * dstride + x] = X + delta;
      }
    }
  }
  
  // Vertically restricted filter
  void aom_clpf_hblock_c(uint8_t *dst, const uint16_t *src, int dstride,
                         int sstride, int sizex, int sizey, unsigned int strength,
                         unsigned int damping) {
    int x, y;
  
    for (y = 0; y < sizey; y++) {
      for (x = 0; x < sizex; x++) {
        const int X = src[y * sstride + x];
        const int A = src[y * sstride + x - 2];
        const int B = src[y * sstride + x - 1];
        const int C = src[y * sstride + x + 1];
        const int D = src[y * sstride + x + 2];
        const int delta = av1_clpf_hsample(X, A, B, C, D, strength, damping);
        dst[y * dstride + x] = X + delta;
      }
    }
  }
  
  void aom_clpf_hblock_hbd_c(uint16_t *dst, const uint16_t *src, int dstride,
                             int sstride, int sizex, int sizey,
                             unsigned int strength, unsigned int damping) {
    int x, y;
  
    for (y = 0; y < sizey; y++) {
      for (x = 0; x < sizex; x++) {
        const int X = src[y * sstride + x];
        const int A = src[y * sstride + x - 2];
        const int B = src[y * sstride + x - 1];
        const int C = src[y * sstride + x + 1];
        const int D = src[y * sstride + x + 2];
        const int delta = av1_clpf_hsample(X, A, B, C, D, strength, damping);
        dst[y * dstride + x] = X + delta;
      }
    }
  }
  