/*
 *  Copyright (c) 2016 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#include <stdlib.h>
#include "vpx/vpx_integer.h"

const int16_t vpx_rv[] = {
  8,  5,  2,  2,  8,  12, 4,  9,  8,  3,  0,  3,  9,  0,  0,  0,  8,  3,  14,
  4,  10, 1,  11, 14, 1,  14, 9,  6,  12, 11, 8,  6,  10, 0,  0,  8,  9,  0,
  3,  14, 8,  11, 13, 4,  2,  9,  0,  3,  9,  6,  1,  2,  3,  14, 13, 1,  8,
  2,  9,  7,  3,  3,  1,  13, 13, 6,  6,  5,  2,  7,  11, 9,  11, 8,  7,  3,
  2,  0,  13, 13, 14, 4,  12, 5,  12, 10, 8,  10, 13, 10, 4,  14, 4,  10, 0,
  8,  11, 1,  13, 7,  7,  14, 6,  14, 13, 2,  13, 5,  4,  4,  0,  10, 0,  5,
  13, 2,  12, 7,  11, 13, 8,  0,  4,  10, 7,  2,  7,  2,  2,  5,  3,  4,  7,
  3,  3,  14, 14, 5,  9,  13, 3,  14, 3,  6,  3,  0,  11, 8,  13, 1,  13, 1,
  12, 0,  10, 9,  7,  6,  2,  8,  5,  2,  13, 7,  1,  13, 14, 7,  6,  7,  9,
  6,  10, 11, 7,  8,  7,  5,  14, 8,  4,  4,  0,  8,  7,  10, 0,  8,  14, 11,
  3,  12, 5,  7,  14, 3,  14, 5,  2,  6,  11, 12, 12, 8,  0,  11, 13, 1,  2,
  0,  5,  10, 14, 7,  8,  0,  4,  11, 0,  8,  0,  3,  10, 5,  8,  0,  11, 6,
  7,  8,  10, 7,  13, 9,  2,  5,  1,  5,  10, 2,  4,  3,  5,  6,  10, 8,  9,
  4,  11, 14, 0,  10, 0,  5,  13, 2,  12, 7,  11, 13, 8,  0,  4,  10, 7,  2,
  7,  2,  2,  5,  3,  4,  7,  3,  3,  14, 14, 5,  9,  13, 3,  14, 3,  6,  3,
  0,  11, 8,  13, 1,  13, 1,  12, 0,  10, 9,  7,  6,  2,  8,  5,  2,  13, 7,
  1,  13, 14, 7,  6,  7,  9,  6,  10, 11, 7,  8,  7,  5,  14, 8,  4,  4,  0,
  8,  7,  10, 0,  8,  14, 11, 3,  12, 5,  7,  14, 3,  14, 5,  2,  6,  11, 12,
  12, 8,  0,  11, 13, 1,  2,  0,  5,  10, 14, 7,  8,  0,  4,  11, 0,  8,  0,
  3,  10, 5,  8,  0,  11, 6,  7,  8,  10, 7,  13, 9,  2,  5,  1,  5,  10, 2,
  4,  3,  5,  6,  10, 8,  9,  4,  11, 14, 3,  8,  3,  7,  8,  5,  11, 4,  12,
  3,  11, 9,  14, 8,  14, 13, 4,  3,  1,  2,  14, 6,  5,  4,  4,  11, 4,  6,
  2,  1,  5,  8,  8,  12, 13, 5,  14, 10, 12, 13, 0,  9,  5,  5,  11, 10, 13,
  9,  10, 13,
};

void vpx_post_proc_down_and_across_mb_row_c(unsigned char *src_ptr,
                                            unsigned char *dst_ptr,
                                            int src_pixels_per_line,
                                            int dst_pixels_per_line, int cols,
                                            unsigned char *f, int size) {
  unsigned char *p_src, *p_dst;
  int row;
  int col;
  unsigned char v;
  unsigned char d[4];

  for (row = 0; row < size; row++) {
    /* post_proc_down for one row */
    p_src = src_ptr;
    p_dst = dst_ptr;

    for (col = 0; col < cols; col++) {
      unsigned char p_above2 = p_src[col - 2 * src_pixels_per_line];
      unsigned char p_above1 = p_src[col - src_pixels_per_line];
      unsigned char p_below1 = p_src[col + src_pixels_per_line];
      unsigned char p_below2 = p_src[col + 2 * src_pixels_per_line];

      v = p_src[col];

      if ((abs(v - p_above2) < f[col]) && (abs(v - p_above1) < f[col]) &&
          (abs(v - p_below1) < f[col]) && (abs(v - p_below2) < f[col])) {
        unsigned char k1, k2, k3;
        k1 = (p_above2 + p_above1 + 1) >> 1;
        k2 = (p_below2 + p_below1 + 1) >> 1;
        k3 = (k1 + k2 + 1) >> 1;
        v = (k3 + v + 1) >> 1;
      }

      p_dst[col] = v;
    }

    /* now post_proc_across */
    p_src = dst_ptr;
    p_dst = dst_ptr;

    p_src[-2] = p_src[-1] = p_src[0];
    p_src[cols] = p_src[cols + 1] = p_src[cols - 1];

    for (col = 0; col < cols; col++) {
      v = p_src[col];

      if ((abs(v - p_src[col - 2]) < f[col]) &&
          (abs(v - p_src[col - 1]) < f[col]) &&
          (abs(v - p_src[col + 1]) < f[col]) &&
          (abs(v - p_src[col + 2]) < f[col])) {
        unsigned char k1, k2, k3;
        k1 = (p_src[col - 2] + p_src[col - 1] + 1) >> 1;
        k2 = (p_src[col + 2] + p_src[col + 1] + 1) >> 1;
        k3 = (k1 + k2 + 1) >> 1;
        v = (k3 + v + 1) >> 1;
      }

      d[col & 3] = v;

      if (col >= 2) p_dst[col - 2] = d[(col - 2) & 3];
    }

    /* handle the last two pixels */
    p_dst[col - 2] = d[(col - 2) & 3];
    p_dst[col - 1] = d[(col - 1) & 3];

    /* next row */
    src_ptr += src_pixels_per_line;
    dst_ptr += dst_pixels_per_line;
  }
}

void vpx_mbpost_proc_across_ip_c(unsigned char *src, int pitch, int rows,
                                 int cols, int flimit) {
  int r, c, i;

  unsigned char *s = src;
  unsigned char d[16];

  for (r = 0; r < rows; r++) {
    int sumsq = 0;
    int sum = 0;

    for (i = -8; i < 0; i++) s[i] = s[0];

    /* 17 avoids valgrind warning - we buffer values in c in d
     * and only write them when we've read 8 ahead...
     */
    for (i = 0; i < 17; i++) s[i + cols] = s[cols - 1];

    for (i = -8; i <= 6; i++) {
      sumsq += s[i] * s[i];
      sum += s[i];
      d[i + 8] = 0;
    }

    for (c = 0; c < cols + 8; c++) {
      int x = s[c + 7] - s[c - 8];
      int y = s[c + 7] + s[c - 8];

      sum += x;
      sumsq += x * y;

      d[c & 15] = s[c];

      if (sumsq * 15 - sum * sum < flimit) {
        d[c & 15] = (8 + sum + s[c]) >> 4;
      }

      s[c - 8] = d[(c - 8) & 15];
    }

    s += pitch;
  }
}

void vpx_mbpost_proc_down_c(unsigned char *dst, int pitch, int rows, int cols,
                            int flimit) {
  int r, c, i;
  const int16_t *rv3 = &vpx_rv[63 & rand()];

  for (c = 0; c < cols; c++) {
    unsigned char *s = &dst[c];
    int sumsq = 0;
    int sum = 0;
    unsigned char d[16];
    const int16_t *rv2 = rv3 + ((c * 17) & 127);

    for (i = -8; i < 0; i++) s[i * pitch] = s[0];

    /* 17 avoids valgrind warning - we buffer values in c in d
     * and only write them when we've read 8 ahead...
     */
    for (i = 0; i < 17; i++) s[(i + rows) * pitch] = s[(rows - 1) * pitch];

    for (i = -8; i <= 6; i++) {
      sumsq += s[i * pitch] * s[i * pitch];
      sum += s[i * pitch];
    }

    for (r = 0; r < rows + 8; r++) {
      sumsq += s[7 * pitch] * s[7 * pitch] - s[-8 * pitch] * s[-8 * pitch];
      sum += s[7 * pitch] - s[-8 * pitch];
      d[r & 15] = s[0];

      if (sumsq * 15 - sum * sum < flimit) {
        d[r & 15] = (rv2[r & 127] + sum + s[0]) >> 4;
      }
      if (r >= 8) s[-8 * pitch] = d[(r - 8) & 15];
      s += pitch;
    }
  }
}