av1/common/cfl.c - aom - Git at Google

 /*
  * 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 "av1/common/cfl.h"
 #include "av1/common/common_data.h"
 #include "av1/common/onyxc_int.h"

 void cfl_init(CFL_CTX *cfl, AV1_COMMON *cm) {
   if (!((cm->subsampling_x == 0 && cm->subsampling_y == 0) ||
         (cm->subsampling_x == 1 && cm->subsampling_y == 1))) {
     aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                        "Only 4:4:4 and 4:2:0 are currently supported by CfL");
   }
   memset(&cfl->pred_buf_q3, 0, sizeof(cfl->pred_buf_q3));
   cfl->subsampling_x = cm->subsampling_x;
   cfl->subsampling_y = cm->subsampling_y;
   cfl->are_parameters_computed = 0;
   cfl->store_y = 0;
 #if CONFIG_DEBUG
   cfl_clear_sub8x8_val(cfl);
 #endif  // CONFIG_DEBUG
 }

 // Due to frame boundary issues, it is possible that the total area covered by
 // chroma exceeds that of luma. When this happens, we fill the missing pixels by
 // repeating the last columns and/or rows.
 static INLINE void cfl_pad(CFL_CTX *cfl, int width, int height) {
   const int diff_width = width - cfl->buf_width;
   const int diff_height = height - cfl->buf_height;

   if (diff_width > 0) {
     const int min_height = height - diff_height;
     int16_t *pred_buf_q3 = cfl->pred_buf_q3 + (width - diff_width);
     for (int j = 0; j < min_height; j++) {
       const int last_pixel = pred_buf_q3[-1];
       for (int i = 0; i < diff_width; i++) {
         pred_buf_q3[i] = last_pixel;
       }
       pred_buf_q3 += MAX_SB_SIZE;
     }
     cfl->buf_width = width;
   }
   if (diff_height > 0) {
     int16_t *pred_buf_q3 =
         cfl->pred_buf_q3 + ((height - diff_height) * MAX_SB_SIZE);
     for (int j = 0; j < diff_height; j++) {
       const int16_t *last_row_q3 = pred_buf_q3 - MAX_SB_SIZE;
       for (int i = 0; i < width; i++) {
         pred_buf_q3[i] = last_row_q3[i];
       }
       pred_buf_q3 += MAX_SB_SIZE;
     }
     cfl->buf_height = height;
   }
 }

 static void sum_above_row_lbd(const uint8_t *above_u, const uint8_t *above_v,
                               int width, int *out_sum_u, int *out_sum_v) {
   int sum_u = 0;
   int sum_v = 0;
   for (int i = 0; i < width; i++) {
     sum_u += above_u[i];
     sum_v += above_v[i];
   }
   *out_sum_u += sum_u;
   *out_sum_v += sum_v;
 }
 #if CONFIG_HIGHBITDEPTH
 static void sum_above_row_hbd(const uint16_t *above_u, const uint16_t *above_v,
                               int width, int *out_sum_u, int *out_sum_v) {
   int sum_u = 0;
   int sum_v = 0;
   for (int i = 0; i < width; i++) {
     sum_u += above_u[i];
     sum_v += above_v[i];
   }
   *out_sum_u += sum_u;
   *out_sum_v += sum_v;
 }
 #endif  // CONFIG_HIGHBITDEPTH

 static void sum_above_row(const MACROBLOCKD *xd, int width, int *out_sum_u,
                           int *out_sum_v) {
   const struct macroblockd_plane *const pd_u = &xd->plane[AOM_PLANE_U];
   const struct macroblockd_plane *const pd_v = &xd->plane[AOM_PLANE_V];
 #if CONFIG_HIGHBITDEPTH
   if (get_bitdepth_data_path_index(xd)) {
     const uint16_t *above_u_16 =
         CONVERT_TO_SHORTPTR(pd_u->dst.buf) - pd_u->dst.stride;
     const uint16_t *above_v_16 =
         CONVERT_TO_SHORTPTR(pd_v->dst.buf) - pd_v->dst.stride;
     sum_above_row_hbd(above_u_16, above_v_16, width, out_sum_u, out_sum_v);
     return;
   }
 #endif  // CONFIG_HIGHBITDEPTH
   const uint8_t *above_u = pd_u->dst.buf - pd_u->dst.stride;
   const uint8_t *above_v = pd_v->dst.buf - pd_v->dst.stride;
   sum_above_row_lbd(above_u, above_v, width, out_sum_u, out_sum_v);
 }

 static void sum_left_col_lbd(const uint8_t *left_u, int u_stride,
                              const uint8_t *left_v, int v_stride, int height,
                              int *out_sum_u, int *out_sum_v) {
   int sum_u = 0;
   int sum_v = 0;
   for (int i = 0; i < height; i++) {
     sum_u += left_u[i * u_stride];
     sum_v += left_v[i * v_stride];
   }
   *out_sum_u += sum_u;
   *out_sum_v += sum_v;
 }
 #if CONFIG_HIGHBITDEPTH
 static void sum_left_col_hbd(const uint16_t *left_u, int u_stride,
                              const uint16_t *left_v, int v_stride, int height,
                              int *out_sum_u, int *out_sum_v) {
   int sum_u = 0;
   int sum_v = 0;
   for (int i = 0; i < height; i++) {
     sum_u += left_u[i * u_stride];
     sum_v += left_v[i * v_stride];
   }
   *out_sum_u += sum_u;
   *out_sum_v += sum_v;
 }
 #endif  // CONFIG_HIGHBITDEPTH
 static void sum_left_col(const MACROBLOCKD *xd, int height, int *out_sum_u,
                          int *out_sum_v) {
   const struct macroblockd_plane *const pd_u = &xd->plane[AOM_PLANE_U];
   const struct macroblockd_plane *const pd_v = &xd->plane[AOM_PLANE_V];

 #if CONFIG_HIGHBITDEPTH
   if (get_bitdepth_data_path_index(xd)) {
     const uint16_t *left_u_16 = CONVERT_TO_SHORTPTR(pd_u->dst.buf) - 1;
     const uint16_t *left_v_16 = CONVERT_TO_SHORTPTR(pd_v->dst.buf) - 1;
     sum_left_col_hbd(left_u_16, pd_u->dst.stride, left_v_16, pd_v->dst.stride,
                      height, out_sum_u, out_sum_v);
     return;
   }
 #endif  // CONFIG_HIGHBITDEPTH
   const uint8_t *left_u = pd_u->dst.buf - 1;
   const uint8_t *left_v = pd_v->dst.buf - 1;
   sum_left_col_lbd(left_u, pd_u->dst.stride, left_v, pd_v->dst.stride, height,
                    out_sum_u, out_sum_v);
 }

 // CfL computes its own block-level DC_PRED. This is required to compute both
 // alpha_cb and alpha_cr before the prediction are computed.
 static void cfl_dc_pred(MACROBLOCKD *xd, BLOCK_SIZE plane_bsize) {
   CFL_CTX *const cfl = xd->cfl;

   // Compute DC_PRED until block boundary. We can't assume the neighbor will use
   // the same transform size.
   const int width = max_block_wide(xd, plane_bsize, AOM_PLANE_U)
                     << tx_size_wide_log2[0];
   const int height = max_block_high(xd, plane_bsize, AOM_PLANE_U)
                      << tx_size_high_log2[0];
   // Number of pixel on the top and left borders.
   const int num_pel = width + height;

   int sum_u = 0;
   int sum_v = 0;

   // Match behavior of build_intra_predictors_high (reconintra.c) at superblock
   // boundaries:
   // base-1 base-1 base-1 .. base-1 base-1 base-1 base-1 base-1 base-1
   // base+1   A      B  ..     Y      Z
   // base+1   C      D  ..     W      X
   // base+1   E      F  ..     U      V
   // base+1   G      H  ..     S      T      T      T      T      T
   // ..

   if (xd->chroma_up_available && xd->mb_to_right_edge >= 0) {
     sum_above_row(xd, width, &sum_u, &sum_v);
   } else {
     const int base = 128 << (xd->bd - 8);
     sum_u = width * (base - 1);
     sum_v = width * (base - 1);
   }

   if (xd->chroma_left_available && xd->mb_to_bottom_edge >= 0) {
     sum_left_col(xd, height, &sum_u, &sum_v);
   } else {
     const int base = 128 << (xd->bd - 8);
     sum_u += height * (base + 1);
     sum_v += height * (base + 1);
   }

   // TODO(ltrudeau) Because of max_block_wide and max_block_high, num_pel will
   // not be a power of two. So these divisions will have to use a lookup table.
   cfl->dc_pred[CFL_PRED_U] = (sum_u + (num_pel >> 1)) / num_pel;
   cfl->dc_pred[CFL_PRED_V] = (sum_v + (num_pel >> 1)) / num_pel;
 }

 static void cfl_subtract_averages(CFL_CTX *cfl, TX_SIZE tx_size) {
   const int width = cfl->uv_width;
   const int height = cfl->uv_height;
   const int tx_height = tx_size_high[tx_size];
   const int tx_width = tx_size_wide[tx_size];
   const int block_row_stride = MAX_SB_SIZE << tx_size_high_log2[tx_size];
   const int num_pel_log2 =
       (tx_size_high_log2[tx_size] + tx_size_wide_log2[tx_size]);

   int16_t *pred_buf_q3 = cfl->pred_buf_q3;

   cfl_pad(cfl, width, height);

   for (int b_j = 0; b_j < height; b_j += tx_height) {
     for (int b_i = 0; b_i < width; b_i += tx_width) {
       int sum_q3 = 0;
       int16_t *tx_pred_buf_q3 = pred_buf_q3;
       for (int t_j = 0; t_j < tx_height; t_j++) {
         for (int t_i = b_i; t_i < b_i + tx_width; t_i++) {
           sum_q3 += tx_pred_buf_q3[t_i];
         }
         tx_pred_buf_q3 += MAX_SB_SIZE;
       }
       int avg_q3 = (sum_q3 + (1 << (num_pel_log2 - 1))) >> num_pel_log2;
       // Loss is never more than 1/2 (in Q3)
       assert(fabs((double)avg_q3 - (sum_q3 / ((double)(1 << num_pel_log2)))) <=
              0.5);

       tx_pred_buf_q3 = pred_buf_q3;
       for (int t_j = 0; t_j < tx_height; t_j++) {
         for (int t_i = b_i; t_i < b_i + tx_width; t_i++) {
           tx_pred_buf_q3[t_i] -= avg_q3;
         }

         tx_pred_buf_q3 += MAX_SB_SIZE;
       }
     }
     pred_buf_q3 += block_row_stride;
   }
 }

 static INLINE int cfl_idx_to_alpha(int alpha_idx, int joint_sign,
                                    CFL_PRED_TYPE pred_type) {
   const int alpha_sign = (pred_type == CFL_PRED_U) ? CFL_SIGN_U(joint_sign)
                                                    : CFL_SIGN_V(joint_sign);
   if (alpha_sign == CFL_SIGN_ZERO) return 0;
   const int abs_alpha_q3 =
       (pred_type == CFL_PRED_U) ? CFL_IDX_U(alpha_idx) : CFL_IDX_V(alpha_idx);
   return (alpha_sign == CFL_SIGN_POS) ? abs_alpha_q3 + 1 : -abs_alpha_q3 - 1;
 }

 static void cfl_build_prediction_lbd(const int16_t *pred_buf_q3, uint8_t *dst,
                                      int dst_stride, int width, int height,
                                      int alpha_q3, int dc_pred) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       dst[i] =
           clip_pixel(get_scaled_luma_q0(alpha_q3, pred_buf_q3[i]) + dc_pred);
     }
     dst += dst_stride;
     pred_buf_q3 += MAX_SB_SIZE;
   }
 }

 #if CONFIG_HIGHBITDEPTH
 static void cfl_build_prediction_hbd(const int16_t *pred_buf_q3, uint16_t *dst,
                                      int dst_stride, int width, int height,
                                      int alpha_q3, int dc_pred, int bit_depth) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       dst[i] = clip_pixel_highbd(
           get_scaled_luma_q0(alpha_q3, pred_buf_q3[i]) + dc_pred, bit_depth);
     }
     dst += dst_stride;
     pred_buf_q3 += MAX_SB_SIZE;
   }
 }
 #endif  // CONFIG_HIGHBITDEPTH

 static void cfl_build_prediction(const int16_t *pred_buf_q3, uint8_t *dst,
                                  int dst_stride, int width, int height,
                                  int alpha_q3, int dc_pred, int use_hbd,
                                  int bit_depth) {
 #if CONFIG_HIGHBITDEPTH
   if (use_hbd) {
     uint16_t *dst_16 = CONVERT_TO_SHORTPTR(dst);
     cfl_build_prediction_hbd(pred_buf_q3, dst_16, dst_stride, width, height,
                              alpha_q3, dc_pred, bit_depth);
     return;
   }
 #endif  // CONFIG_HIGHBITDEPTH
   (void)use_hbd;
   (void)bit_depth;
   cfl_build_prediction_lbd(pred_buf_q3, dst, dst_stride, width, height,
                            alpha_q3, dc_pred);
 }

 void cfl_predict_block(MACROBLOCKD *const xd, uint8_t *dst, int dst_stride,
                        int row, int col, TX_SIZE tx_size, int plane) {
   CFL_CTX *const cfl = xd->cfl;
   MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;

   // CfL parameters must be computed before prediction can be done.
   assert(cfl->are_parameters_computed == 1);

   const int16_t *pred_buf_q3 =
       cfl->pred_buf_q3 + ((row * MAX_SB_SIZE + col) << tx_size_wide_log2[0]);
   const int alpha_q3 =
       cfl_idx_to_alpha(mbmi->cfl_alpha_idx, mbmi->cfl_alpha_signs, plane - 1);

   cfl_build_prediction(pred_buf_q3, dst, dst_stride, tx_size_wide[tx_size],
                        tx_size_high[tx_size], alpha_q3, cfl->dc_pred[plane - 1],
                        get_bitdepth_data_path_index(xd), xd->bd);
 }

 static void cfl_luma_subsampling_420_lbd(const uint8_t *input, int input_stride,
                                          int16_t *output_q3, int width,
                                          int height) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       int top = i << 1;
       int bot = top + input_stride;
       output_q3[i] = (input[top] + input[top + 1] + input[bot] + input[bot + 1])
                      << 1;
     }
     input += input_stride << 1;
     output_q3 += MAX_SB_SIZE;
   }
 }

 static void cfl_luma_subsampling_444_lbd(const uint8_t *input, int input_stride,
                                          int16_t *output_q3, int width,
                                          int height) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       output_q3[i] = input[i] << 3;
     }
     input += input_stride;
     output_q3 += MAX_SB_SIZE;
   }
 }

 #if CONFIG_HIGHBITDEPTH
 static void cfl_luma_subsampling_420_hbd(const uint16_t *input,
                                          int input_stride, int16_t *output_q3,
                                          int width, int height) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       int top = i << 1;
       int bot = top + input_stride;
       output_q3[i] = (input[top] + input[top + 1] + input[bot] + input[bot + 1])
                      << 1;
     }
     input += input_stride << 1;
     output_q3 += MAX_SB_SIZE;
   }
 }

 static void cfl_luma_subsampling_444_hbd(const uint16_t *input,
                                          int input_stride, int16_t *output_q3,
                                          int width, int height) {
   for (int j = 0; j < height; j++) {
     for (int i = 0; i < width; i++) {
       output_q3[i] = input[i] << 3;
     }
     input += input_stride;
     output_q3 += MAX_SB_SIZE;
   }
 }
 #endif  // CONFIG_HIGHBITDEPTH

 static void cfl_luma_subsampling_420(const uint8_t *input, int input_stride,
                                      int16_t *output_q3, int width, int height,
                                      int use_hbd) {
 #if CONFIG_HIGHBITDEPTH
   if (use_hbd) {
     const uint16_t *input_16 = CONVERT_TO_SHORTPTR(input);
     cfl_luma_subsampling_420_hbd(input_16, input_stride, output_q3, width,
                                  height);
     return;
   }
 #endif  // CONFIG_HIGHBITDEPTH
   (void)use_hbd;
   cfl_luma_subsampling_420_lbd(input, input_stride, output_q3, width, height);
 }

 static void cfl_luma_subsampling_444(const uint8_t *input, int input_stride,
                                      int16_t *output_q3, int width, int height,
                                      int use_hbd) {
 #if CONFIG_HIGHBITDEPTH
   if (use_hbd) {
     uint16_t *input_16 = CONVERT_TO_SHORTPTR(input);
     cfl_luma_subsampling_444_hbd(input_16, input_stride, output_q3, width,
                                  height);
     return;
   }
 #endif  // CONFIG_HIGHBITDEPTH
   (void)use_hbd;
   cfl_luma_subsampling_444_lbd(input, input_stride, output_q3, width, height);
 }

 static INLINE void cfl_store(CFL_CTX *cfl, const uint8_t *input,
                              int input_stride, int row, int col, int width,
                              int height, int use_hbd) {
   const int tx_off_log2 = tx_size_wide_log2[0];
   const int sub_x = cfl->subsampling_x;
   const int sub_y = cfl->subsampling_y;
   const int store_row = row << (tx_off_log2 - sub_y);
   const int store_col = col << (tx_off_log2 - sub_x);
   const int store_height = height >> sub_y;
   const int store_width = width >> sub_x;

   // Invalidate current parameters
   cfl->are_parameters_computed = 0;

   // Store the surface of the pixel buffer that was written to, this way we
   // can manage chroma overrun (e.g. when the chroma surfaces goes beyond the
   // frame boundary)
   if (col == 0 && row == 0) {
     cfl->buf_width = store_width;
     cfl->buf_height = store_height;
   } else {
     cfl->buf_width = OD_MAXI(store_col + store_width, cfl->buf_width);
     cfl->buf_height = OD_MAXI(store_row + store_height, cfl->buf_height);
   }

   // Check that we will remain inside the pixel buffer.
   assert(store_row + store_height <= MAX_SB_SIZE);
   assert(store_col + store_width <= MAX_SB_SIZE);

   // Store the input into the CfL pixel buffer
   int16_t *pred_buf_q3 =
       cfl->pred_buf_q3 + (store_row * MAX_SB_SIZE + store_col);

   if (sub_y == 0 && sub_x == 0) {
     cfl_luma_subsampling_444(input, input_stride, pred_buf_q3, store_width,
                              store_height, use_hbd);
   } else if (sub_y == 1 && sub_x == 1) {
     cfl_luma_subsampling_420(input, input_stride, pred_buf_q3, store_width,
                              store_height, use_hbd);
   } else {
     // TODO(ltrudeau) add support for 4:2:2
     assert(0);  // Unsupported chroma subsampling
   }
 }

 // Adjust the row and column of blocks smaller than 8X8, as chroma-referenced
 // and non-chroma-referenced blocks are stored together in the CfL buffer.
 static INLINE void sub8x8_adjust_offset(const CFL_CTX *cfl, int *row_out,
                                         int *col_out) {
   // Increment row index for bottom: 8x4, 16x4 or both bottom 4x4s.
   if ((cfl->mi_row & 0x01) && cfl->subsampling_y) {
     assert(*row_out == 0);
     (*row_out)++;
   }

   // Increment col index for right: 4x8, 4x16 or both right 4x4s.
   if ((cfl->mi_col & 0x01) && cfl->subsampling_x) {
     assert(*col_out == 0);
     (*col_out)++;
   }
 }
 #if CONFIG_DEBUG
 static INLINE void sub8x8_set_val(CFL_CTX *cfl, int row, int col, int val_high,
                                   int val_wide) {
   for (int val_r = 0; val_r < val_high; val_r++) {
     assert(row + val_r < CFL_SUB8X8_VAL_MI_SIZE);
     int row_off = (row + val_r) * CFL_SUB8X8_VAL_MI_SIZE;
     for (int val_c = 0; val_c < val_wide; val_c++) {
       assert(col + val_c < CFL_SUB8X8_VAL_MI_SIZE);
       assert(cfl->sub8x8_val[row_off + col + val_c] == 0);
       cfl->sub8x8_val[row_off + col + val_c]++;
     }
   }
 }
 #endif  // CONFIG_DEBUG

 void cfl_store_tx(MACROBLOCKD *const xd, int row, int col, TX_SIZE tx_size,
                   BLOCK_SIZE bsize) {
   CFL_CTX *const cfl = xd->cfl;
   struct macroblockd_plane *const pd = &xd->plane[AOM_PLANE_Y];
   uint8_t *dst =
       &pd->dst.buf[(row * pd->dst.stride + col) << tx_size_wide_log2[0]];
   (void)bsize;
   if (block_size_high[bsize] == 4 || block_size_wide[bsize] == 4) {
     // Only dimensions of size 4 can have an odd offset.
     assert(!((col & 1) && tx_size_wide[tx_size] != 4));
     assert(!((row & 1) && tx_size_high[tx_size] != 4));
     sub8x8_adjust_offset(cfl, &row, &col);
 #if CONFIG_DEBUG
     sub8x8_set_val(cfl, row, col, tx_size_high_unit[tx_size],
                    tx_size_wide_unit[tx_size]);
 #endif  // CONFIG_DEBUG
   }
   cfl_store(cfl, dst, pd->dst.stride, row, col, tx_size_wide[tx_size],
             tx_size_high[tx_size], get_bitdepth_data_path_index(xd));
 }

 void cfl_store_block(MACROBLOCKD *const xd, BLOCK_SIZE bsize, TX_SIZE tx_size) {
   CFL_CTX *const cfl = xd->cfl;
   struct macroblockd_plane *const pd = &xd->plane[AOM_PLANE_Y];
   int row = 0;
   int col = 0;
   bsize = AOMMAX(BLOCK_4X4, bsize);
   if (block_size_high[bsize] == 4 || block_size_wide[bsize] == 4) {
     sub8x8_adjust_offset(cfl, &row, &col);
 #if CONFIG_DEBUG
     sub8x8_set_val(cfl, row, col, mi_size_high[bsize], mi_size_wide[bsize]);
 #endif  // CONFIG_DEBUG
   }
   const int width = max_intra_block_width(xd, bsize, AOM_PLANE_Y, tx_size);
   const int height = max_intra_block_height(xd, bsize, AOM_PLANE_Y, tx_size);
   cfl_store(cfl, pd->dst.buf, pd->dst.stride, row, col, width, height,
             get_bitdepth_data_path_index(xd));
 }

 void cfl_compute_parameters(MACROBLOCKD *const xd, TX_SIZE tx_size) {
   CFL_CTX *const cfl = xd->cfl;
   MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;

   // Do not call cfl_compute_parameters multiple time on the same values.
   assert(cfl->are_parameters_computed == 0);

   const BLOCK_SIZE plane_bsize = AOMMAX(
       BLOCK_4X4, get_plane_block_size(mbmi->sb_type, &xd->plane[AOM_PLANE_U]));
 #if CONFIG_DEBUG
   if (mbmi->sb_type < BLOCK_8X8) {
     for (int val_r = 0; val_r < mi_size_high[mbmi->sb_type]; val_r++) {
       for (int val_c = 0; val_c < mi_size_wide[mbmi->sb_type]; val_c++) {
         assert(cfl->sub8x8_val[val_r * CFL_SUB8X8_VAL_MI_SIZE + val_c] == 1);
       }
     }
     cfl_clear_sub8x8_val(cfl);
   }
 #endif  // CONFIG_DEBUG
   // AOM_PLANE_U is used, but both planes will have the same sizes.
   cfl->uv_width = max_intra_block_width(xd, plane_bsize, AOM_PLANE_U, tx_size);
   cfl->uv_height =
       max_intra_block_height(xd, plane_bsize, AOM_PLANE_U, tx_size);

   assert(cfl->buf_width <= cfl->uv_width);
   assert(cfl->buf_height <= cfl->uv_height);

   cfl_dc_pred(xd, plane_bsize);
   cfl_subtract_averages(cfl, tx_size);
   cfl->are_parameters_computed = 1;
 }
	/*
	* 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 "av1/common/cfl.h"
	#include "av1/common/common_data.h"
	#include "av1/common/onyxc_int.h"

	void cfl_init(CFL_CTX cfl, AV1_COMMON cm) {
	if (!((cm->subsampling_x == 0 && cm->subsampling_y == 0) \|\|
	(cm->subsampling_x == 1 && cm->subsampling_y == 1))) {
	aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
	"Only 4:4:4 and 4:2:0 are currently supported by CfL");
	}
	memset(&cfl->pred_buf_q3, 0, sizeof(cfl->pred_buf_q3));
	cfl->subsampling_x = cm->subsampling_x;
	cfl->subsampling_y = cm->subsampling_y;
	cfl->are_parameters_computed = 0;
	cfl->store_y = 0;
	#if CONFIG_DEBUG
	cfl_clear_sub8x8_val(cfl);
	#endif // CONFIG_DEBUG
	}

	// Due to frame boundary issues, it is possible that the total area covered by
	// chroma exceeds that of luma. When this happens, we fill the missing pixels by
	// repeating the last columns and/or rows.
	static INLINE void cfl_pad(CFL_CTX *cfl, int width, int height) {
	const int diff_width = width - cfl->buf_width;
	const int diff_height = height - cfl->buf_height;

	if (diff_width > 0) {
	const int min_height = height - diff_height;
	int16_t *pred_buf_q3 = cfl->pred_buf_q3 + (width - diff_width);
	for (int j = 0; j < min_height; j++) {
	const int last_pixel = pred_buf_q3[-1];
	for (int i = 0; i < diff_width; i++) {
	pred_buf_q3[i] = last_pixel;
	}
	pred_buf_q3 += MAX_SB_SIZE;
	}
	cfl->buf_width = width;
	}
	if (diff_height > 0) {
	int16_t *pred_buf_q3 =
	cfl->pred_buf_q3 + ((height - diff_height) * MAX_SB_SIZE);
	for (int j = 0; j < diff_height; j++) {
	const int16_t *last_row_q3 = pred_buf_q3 - MAX_SB_SIZE;
	for (int i = 0; i < width; i++) {
	pred_buf_q3[i] = last_row_q3[i];
	}
	pred_buf_q3 += MAX_SB_SIZE;
	}
	cfl->buf_height = height;
	}
	}

	static void sum_above_row_lbd(const uint8_t above_u, const uint8_t above_v,
	int width, int out_sum_u, int out_sum_v) {
	int sum_u = 0;
	int sum_v = 0;
	for (int i = 0; i < width; i++) {
	sum_u += above_u[i];
	sum_v += above_v[i];
	}
	*out_sum_u += sum_u;
	*out_sum_v += sum_v;
	}
	#if CONFIG_HIGHBITDEPTH
	static void sum_above_row_hbd(const uint16_t above_u, const uint16_t above_v,
	int width, int out_sum_u, int out_sum_v) {
	int sum_u = 0;
	int sum_v = 0;
	for (int i = 0; i < width; i++) {
	sum_u += above_u[i];
	sum_v += above_v[i];
	}
	*out_sum_u += sum_u;
	*out_sum_v += sum_v;
	}
	#endif // CONFIG_HIGHBITDEPTH

	static void sum_above_row(const MACROBLOCKD xd, int width, int out_sum_u,
	int *out_sum_v) {
	const struct macroblockd_plane *const pd_u = &xd->plane[AOM_PLANE_U];
	const struct macroblockd_plane *const pd_v = &xd->plane[AOM_PLANE_V];
	#if CONFIG_HIGHBITDEPTH
	if (get_bitdepth_data_path_index(xd)) {
	const uint16_t *above_u_16 =
	CONVERT_TO_SHORTPTR(pd_u->dst.buf) - pd_u->dst.stride;
	const uint16_t *above_v_16 =
	CONVERT_TO_SHORTPTR(pd_v->dst.buf) - pd_v->dst.stride;
	sum_above_row_hbd(above_u_16, above_v_16, width, out_sum_u, out_sum_v);
	return;
	}
	#endif // CONFIG_HIGHBITDEPTH
	const uint8_t *above_u = pd_u->dst.buf - pd_u->dst.stride;
	const uint8_t *above_v = pd_v->dst.buf - pd_v->dst.stride;
	sum_above_row_lbd(above_u, above_v, width, out_sum_u, out_sum_v);
	}

	static void sum_left_col_lbd(const uint8_t *left_u, int u_stride,
	const uint8_t *left_v, int v_stride, int height,
	int out_sum_u, int out_sum_v) {
	int sum_u = 0;
	int sum_v = 0;
	for (int i = 0; i < height; i++) {
	sum_u += left_u[i * u_stride];
	sum_v += left_v[i * v_stride];
	}
	*out_sum_u += sum_u;
	*out_sum_v += sum_v;
	}
	#if CONFIG_HIGHBITDEPTH
	static void sum_left_col_hbd(const uint16_t *left_u, int u_stride,
	const uint16_t *left_v, int v_stride, int height,
	int out_sum_u, int out_sum_v) {
	int sum_u = 0;
	int sum_v = 0;
	for (int i = 0; i < height; i++) {
	sum_u += left_u[i * u_stride];
	sum_v += left_v[i * v_stride];
	}
	*out_sum_u += sum_u;
	*out_sum_v += sum_v;
	}
	#endif // CONFIG_HIGHBITDEPTH
	static void sum_left_col(const MACROBLOCKD xd, int height, int out_sum_u,
	int *out_sum_v) {
	const struct macroblockd_plane *const pd_u = &xd->plane[AOM_PLANE_U];
	const struct macroblockd_plane *const pd_v = &xd->plane[AOM_PLANE_V];

	#if CONFIG_HIGHBITDEPTH
	if (get_bitdepth_data_path_index(xd)) {
	const uint16_t *left_u_16 = CONVERT_TO_SHORTPTR(pd_u->dst.buf) - 1;
	const uint16_t *left_v_16 = CONVERT_TO_SHORTPTR(pd_v->dst.buf) - 1;
	sum_left_col_hbd(left_u_16, pd_u->dst.stride, left_v_16, pd_v->dst.stride,
	height, out_sum_u, out_sum_v);
	return;
	}
	#endif // CONFIG_HIGHBITDEPTH
	const uint8_t *left_u = pd_u->dst.buf - 1;
	const uint8_t *left_v = pd_v->dst.buf - 1;
	sum_left_col_lbd(left_u, pd_u->dst.stride, left_v, pd_v->dst.stride, height,
	out_sum_u, out_sum_v);
	}

	// CfL computes its own block-level DC_PRED. This is required to compute both
	// alpha_cb and alpha_cr before the prediction are computed.
	static void cfl_dc_pred(MACROBLOCKD *xd, BLOCK_SIZE plane_bsize) {
	CFL_CTX *const cfl = xd->cfl;

	// Compute DC_PRED until block boundary. We can't assume the neighbor will use
	// the same transform size.
	const int width = max_block_wide(xd, plane_bsize, AOM_PLANE_U)
	<< tx_size_wide_log2[0];
	const int height = max_block_high(xd, plane_bsize, AOM_PLANE_U)
	<< tx_size_high_log2[0];
	// Number of pixel on the top and left borders.
	const int num_pel = width + height;

	int sum_u = 0;
	int sum_v = 0;

	// Match behavior of build_intra_predictors_high (reconintra.c) at superblock
	// boundaries:
	// base-1 base-1 base-1 .. base-1 base-1 base-1 base-1 base-1 base-1
	// base+1 A B .. Y Z
	// base+1 C D .. W X
	// base+1 E F .. U V
	// base+1 G H .. S T T T T T
	// ..

	if (xd->chroma_up_available && xd->mb_to_right_edge >= 0) {
	sum_above_row(xd, width, &sum_u, &sum_v);
	} else {
	const int base = 128 << (xd->bd - 8);
	sum_u = width * (base - 1);
	sum_v = width * (base - 1);
	}

	if (xd->chroma_left_available && xd->mb_to_bottom_edge >= 0) {
	sum_left_col(xd, height, &sum_u, &sum_v);
	} else {
	const int base = 128 << (xd->bd - 8);
	sum_u += height * (base + 1);
	sum_v += height * (base + 1);
	}

	// TODO(ltrudeau) Because of max_block_wide and max_block_high, num_pel will
	// not be a power of two. So these divisions will have to use a lookup table.
	cfl->dc_pred[CFL_PRED_U] = (sum_u + (num_pel >> 1)) / num_pel;
	cfl->dc_pred[CFL_PRED_V] = (sum_v + (num_pel >> 1)) / num_pel;
	}

	static void cfl_subtract_averages(CFL_CTX *cfl, TX_SIZE tx_size) {
	const int width = cfl->uv_width;
	const int height = cfl->uv_height;
	const int tx_height = tx_size_high[tx_size];
	const int tx_width = tx_size_wide[tx_size];
	const int block_row_stride = MAX_SB_SIZE << tx_size_high_log2[tx_size];
	const int num_pel_log2 =
	(tx_size_high_log2[tx_size] + tx_size_wide_log2[tx_size]);

	int16_t *pred_buf_q3 = cfl->pred_buf_q3;

	cfl_pad(cfl, width, height);

	for (int b_j = 0; b_j < height; b_j += tx_height) {
	for (int b_i = 0; b_i < width; b_i += tx_width) {
	int sum_q3 = 0;
	int16_t *tx_pred_buf_q3 = pred_buf_q3;
	for (int t_j = 0; t_j < tx_height; t_j++) {
	for (int t_i = b_i; t_i < b_i + tx_width; t_i++) {
	sum_q3 += tx_pred_buf_q3[t_i];
	}
	tx_pred_buf_q3 += MAX_SB_SIZE;
	}
	int avg_q3 = (sum_q3 + (1 << (num_pel_log2 - 1))) >> num_pel_log2;
	// Loss is never more than 1/2 (in Q3)
	assert(fabs((double)avg_q3 - (sum_q3 / ((double)(1 << num_pel_log2)))) <=
	0.5);

	tx_pred_buf_q3 = pred_buf_q3;
	for (int t_j = 0; t_j < tx_height; t_j++) {
	for (int t_i = b_i; t_i < b_i + tx_width; t_i++) {
	tx_pred_buf_q3[t_i] -= avg_q3;
	}

	tx_pred_buf_q3 += MAX_SB_SIZE;
	}
	}
	pred_buf_q3 += block_row_stride;
	}
	}

	static INLINE int cfl_idx_to_alpha(int alpha_idx, int joint_sign,
	CFL_PRED_TYPE pred_type) {
	const int alpha_sign = (pred_type == CFL_PRED_U) ? CFL_SIGN_U(joint_sign)
	: CFL_SIGN_V(joint_sign);
	if (alpha_sign == CFL_SIGN_ZERO) return 0;
	const int abs_alpha_q3 =
	(pred_type == CFL_PRED_U) ? CFL_IDX_U(alpha_idx) : CFL_IDX_V(alpha_idx);
	return (alpha_sign == CFL_SIGN_POS) ? abs_alpha_q3 + 1 : -abs_alpha_q3 - 1;
	}

	static void cfl_build_prediction_lbd(const int16_t pred_buf_q3, uint8_t dst,
	int dst_stride, int width, int height,
	int alpha_q3, int dc_pred) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	dst[i] =
	clip_pixel(get_scaled_luma_q0(alpha_q3, pred_buf_q3[i]) + dc_pred);
	}
	dst += dst_stride;
	pred_buf_q3 += MAX_SB_SIZE;
	}
	}

	#if CONFIG_HIGHBITDEPTH
	static void cfl_build_prediction_hbd(const int16_t pred_buf_q3, uint16_t dst,
	int dst_stride, int width, int height,
	int alpha_q3, int dc_pred, int bit_depth) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	dst[i] = clip_pixel_highbd(
	get_scaled_luma_q0(alpha_q3, pred_buf_q3[i]) + dc_pred, bit_depth);
	}
	dst += dst_stride;
	pred_buf_q3 += MAX_SB_SIZE;
	}
	}
	#endif // CONFIG_HIGHBITDEPTH

	static void cfl_build_prediction(const int16_t pred_buf_q3, uint8_t dst,
	int dst_stride, int width, int height,
	int alpha_q3, int dc_pred, int use_hbd,
	int bit_depth) {
	#if CONFIG_HIGHBITDEPTH
	if (use_hbd) {
	uint16_t *dst_16 = CONVERT_TO_SHORTPTR(dst);
	cfl_build_prediction_hbd(pred_buf_q3, dst_16, dst_stride, width, height,
	alpha_q3, dc_pred, bit_depth);
	return;
	}
	#endif // CONFIG_HIGHBITDEPTH
	(void)use_hbd;
	(void)bit_depth;
	cfl_build_prediction_lbd(pred_buf_q3, dst, dst_stride, width, height,
	alpha_q3, dc_pred);
	}

	void cfl_predict_block(MACROBLOCKD const xd, uint8_t dst, int dst_stride,
	int row, int col, TX_SIZE tx_size, int plane) {
	CFL_CTX *const cfl = xd->cfl;
	MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;

	// CfL parameters must be computed before prediction can be done.
	assert(cfl->are_parameters_computed == 1);

	const int16_t *pred_buf_q3 =
	cfl->pred_buf_q3 + ((row * MAX_SB_SIZE + col) << tx_size_wide_log2[0]);
	const int alpha_q3 =
	cfl_idx_to_alpha(mbmi->cfl_alpha_idx, mbmi->cfl_alpha_signs, plane - 1);

	cfl_build_prediction(pred_buf_q3, dst, dst_stride, tx_size_wide[tx_size],
	tx_size_high[tx_size], alpha_q3, cfl->dc_pred[plane - 1],
	get_bitdepth_data_path_index(xd), xd->bd);
	}

	static void cfl_luma_subsampling_420_lbd(const uint8_t *input, int input_stride,
	int16_t *output_q3, int width,
	int height) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	int top = i << 1;
	int bot = top + input_stride;
	output_q3[i] = (input[top] + input[top + 1] + input[bot] + input[bot + 1])
	<< 1;
	}
	input += input_stride << 1;
	output_q3 += MAX_SB_SIZE;
	}
	}

	static void cfl_luma_subsampling_444_lbd(const uint8_t *input, int input_stride,
	int16_t *output_q3, int width,
	int height) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	output_q3[i] = input[i] << 3;
	}
	input += input_stride;
	output_q3 += MAX_SB_SIZE;
	}
	}

	#if CONFIG_HIGHBITDEPTH
	static void cfl_luma_subsampling_420_hbd(const uint16_t *input,
	int input_stride, int16_t *output_q3,
	int width, int height) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	int top = i << 1;
	int bot = top + input_stride;
	output_q3[i] = (input[top] + input[top + 1] + input[bot] + input[bot + 1])
	<< 1;
	}
	input += input_stride << 1;
	output_q3 += MAX_SB_SIZE;
	}
	}

	static void cfl_luma_subsampling_444_hbd(const uint16_t *input,
	int input_stride, int16_t *output_q3,
	int width, int height) {
	for (int j = 0; j < height; j++) {
	for (int i = 0; i < width; i++) {
	output_q3[i] = input[i] << 3;
	}
	input += input_stride;
	output_q3 += MAX_SB_SIZE;
	}
	}
	#endif // CONFIG_HIGHBITDEPTH

	static void cfl_luma_subsampling_420(const uint8_t *input, int input_stride,
	int16_t *output_q3, int width, int height,
	int use_hbd) {
	#if CONFIG_HIGHBITDEPTH
	if (use_hbd) {
	const uint16_t *input_16 = CONVERT_TO_SHORTPTR(input);
	cfl_luma_subsampling_420_hbd(input_16, input_stride, output_q3, width,
	height);
	return;
	}
	#endif // CONFIG_HIGHBITDEPTH
	(void)use_hbd;
	cfl_luma_subsampling_420_lbd(input, input_stride, output_q3, width, height);
	}

	static void cfl_luma_subsampling_444(const uint8_t *input, int input_stride,
	int16_t *output_q3, int width, int height,
	int use_hbd) {
	#if CONFIG_HIGHBITDEPTH
	if (use_hbd) {
	uint16_t *input_16 = CONVERT_TO_SHORTPTR(input);
	cfl_luma_subsampling_444_hbd(input_16, input_stride, output_q3, width,
	height);
	return;
	}
	#endif // CONFIG_HIGHBITDEPTH
	(void)use_hbd;
	cfl_luma_subsampling_444_lbd(input, input_stride, output_q3, width, height);
	}

	static INLINE void cfl_store(CFL_CTX cfl, const uint8_t input,
	int input_stride, int row, int col, int width,
	int height, int use_hbd) {
	const int tx_off_log2 = tx_size_wide_log2[0];
	const int sub_x = cfl->subsampling_x;
	const int sub_y = cfl->subsampling_y;
	const int store_row = row << (tx_off_log2 - sub_y);
	const int store_col = col << (tx_off_log2 - sub_x);
	const int store_height = height >> sub_y;
	const int store_width = width >> sub_x;

	// Invalidate current parameters
	cfl->are_parameters_computed = 0;

	// Store the surface of the pixel buffer that was written to, this way we
	// can manage chroma overrun (e.g. when the chroma surfaces goes beyond the
	// frame boundary)
	if (col == 0 && row == 0) {
	cfl->buf_width = store_width;
	cfl->buf_height = store_height;
	} else {
	cfl->buf_width = OD_MAXI(store_col + store_width, cfl->buf_width);
	cfl->buf_height = OD_MAXI(store_row + store_height, cfl->buf_height);
	}

	// Check that we will remain inside the pixel buffer.
	assert(store_row + store_height <= MAX_SB_SIZE);
	assert(store_col + store_width <= MAX_SB_SIZE);

	// Store the input into the CfL pixel buffer
	int16_t *pred_buf_q3 =
	cfl->pred_buf_q3 + (store_row * MAX_SB_SIZE + store_col);

	if (sub_y == 0 && sub_x == 0) {
	cfl_luma_subsampling_444(input, input_stride, pred_buf_q3, store_width,
	store_height, use_hbd);
	} else if (sub_y == 1 && sub_x == 1) {
	cfl_luma_subsampling_420(input, input_stride, pred_buf_q3, store_width,
	store_height, use_hbd);
	} else {
	// TODO(ltrudeau) add support for 4:2:2
	assert(0); // Unsupported chroma subsampling
	}
	}

	// Adjust the row and column of blocks smaller than 8X8, as chroma-referenced
	// and non-chroma-referenced blocks are stored together in the CfL buffer.
	static INLINE void sub8x8_adjust_offset(const CFL_CTX cfl, int row_out,
	int *col_out) {
	// Increment row index for bottom: 8x4, 16x4 or both bottom 4x4s.
	if ((cfl->mi_row & 0x01) && cfl->subsampling_y) {
	assert(*row_out == 0);
	(*row_out)++;
	}

	// Increment col index for right: 4x8, 4x16 or both right 4x4s.
	if ((cfl->mi_col & 0x01) && cfl->subsampling_x) {
	assert(*col_out == 0);
	(*col_out)++;
	}
	}
	#if CONFIG_DEBUG
	static INLINE void sub8x8_set_val(CFL_CTX *cfl, int row, int col, int val_high,
	int val_wide) {
	for (int val_r = 0; val_r < val_high; val_r++) {
	assert(row + val_r < CFL_SUB8X8_VAL_MI_SIZE);
	int row_off = (row + val_r) * CFL_SUB8X8_VAL_MI_SIZE;
	for (int val_c = 0; val_c < val_wide; val_c++) {
	assert(col + val_c < CFL_SUB8X8_VAL_MI_SIZE);
	assert(cfl->sub8x8_val[row_off + col + val_c] == 0);
	cfl->sub8x8_val[row_off + col + val_c]++;
	}
	}
	}
	#endif // CONFIG_DEBUG

	void cfl_store_tx(MACROBLOCKD *const xd, int row, int col, TX_SIZE tx_size,
	BLOCK_SIZE bsize) {
	CFL_CTX *const cfl = xd->cfl;
	struct macroblockd_plane *const pd = &xd->plane[AOM_PLANE_Y];
	uint8_t *dst =
	&pd->dst.buf[(row * pd->dst.stride + col) << tx_size_wide_log2[0]];
	(void)bsize;
	if (block_size_high[bsize] == 4 \|\| block_size_wide[bsize] == 4) {
	// Only dimensions of size 4 can have an odd offset.
	assert(!((col & 1) && tx_size_wide[tx_size] != 4));
	assert(!((row & 1) && tx_size_high[tx_size] != 4));
	sub8x8_adjust_offset(cfl, &row, &col);
	#if CONFIG_DEBUG
	sub8x8_set_val(cfl, row, col, tx_size_high_unit[tx_size],
	tx_size_wide_unit[tx_size]);
	#endif // CONFIG_DEBUG
	}
	cfl_store(cfl, dst, pd->dst.stride, row, col, tx_size_wide[tx_size],
	tx_size_high[tx_size], get_bitdepth_data_path_index(xd));
	}

	void cfl_store_block(MACROBLOCKD *const xd, BLOCK_SIZE bsize, TX_SIZE tx_size) {
	CFL_CTX *const cfl = xd->cfl;
	struct macroblockd_plane *const pd = &xd->plane[AOM_PLANE_Y];
	int row = 0;
	int col = 0;
	bsize = AOMMAX(BLOCK_4X4, bsize);
	if (block_size_high[bsize] == 4 \|\| block_size_wide[bsize] == 4) {
	sub8x8_adjust_offset(cfl, &row, &col);
	#if CONFIG_DEBUG
	sub8x8_set_val(cfl, row, col, mi_size_high[bsize], mi_size_wide[bsize]);
	#endif // CONFIG_DEBUG
	}
	const int width = max_intra_block_width(xd, bsize, AOM_PLANE_Y, tx_size);
	const int height = max_intra_block_height(xd, bsize, AOM_PLANE_Y, tx_size);
	cfl_store(cfl, pd->dst.buf, pd->dst.stride, row, col, width, height,
	get_bitdepth_data_path_index(xd));
	}

	void cfl_compute_parameters(MACROBLOCKD *const xd, TX_SIZE tx_size) {
	CFL_CTX *const cfl = xd->cfl;
	MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;

	// Do not call cfl_compute_parameters multiple time on the same values.
	assert(cfl->are_parameters_computed == 0);

	const BLOCK_SIZE plane_bsize = AOMMAX(
	BLOCK_4X4, get_plane_block_size(mbmi->sb_type, &xd->plane[AOM_PLANE_U]));
	#if CONFIG_DEBUG
	if (mbmi->sb_type < BLOCK_8X8) {
	for (int val_r = 0; val_r < mi_size_high[mbmi->sb_type]; val_r++) {
	for (int val_c = 0; val_c < mi_size_wide[mbmi->sb_type]; val_c++) {
	assert(cfl->sub8x8_val[val_r * CFL_SUB8X8_VAL_MI_SIZE + val_c] == 1);
	}
	}
	cfl_clear_sub8x8_val(cfl);
	}
	#endif // CONFIG_DEBUG
	// AOM_PLANE_U is used, but both planes will have the same sizes.
	cfl->uv_width = max_intra_block_width(xd, plane_bsize, AOM_PLANE_U, tx_size);
	cfl->uv_height =
	max_intra_block_height(xd, plane_bsize, AOM_PLANE_U, tx_size);

	assert(cfl->buf_width <= cfl->uv_width);
	assert(cfl->buf_height <= cfl->uv_height);

	cfl_dc_pred(xd, plane_bsize);
	cfl_subtract_averages(cfl, tx_size);
	cfl->are_parameters_computed = 1;
	}