decodetxb.c 6.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12
/*
 * Copyright (c) 2017, 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/scan.h"
Angie Chiang's avatar
Angie Chiang committed
13
#include "av1/common/idct.h"
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
#include "av1/common/txb_common.h"
#include "av1/decoder/decodetxb.h"

#define ACCT_STR __func__

static int read_golomb(aom_reader *r) {
  int x = 1;
  int length = 0;
  int i = 0;

  while (!i) {
    i = aom_read_bit(r, ACCT_STR);
    ++length;
  }

  for (i = 0; i < length - 1; ++i) {
    x <<= 1;
    x += aom_read_bit(r, ACCT_STR);
  }

  return x - 1;
}

uint8_t av1_read_coeffs_txb(const AV1_COMMON *const cm, MACROBLOCKD *xd,
                            aom_reader *r, int block, int plane,
Angie Chiang's avatar
Angie Chiang committed
39
                            tran_low_t *tcoeffs, TXB_CTX *txb_ctx,
40
                            int16_t *max_scan_line, int *eob) {
41
  FRAME_COUNTS *counts = xd->counts;
Angie Chiang's avatar
Angie Chiang committed
42
  TX_SIZE tx_size = get_tx_size(plane, xd);
43 44 45 46 47 48 49 50 51 52
  PLANE_TYPE plane_type = get_plane_type(plane);
  aom_prob *nz_map = cm->fc->nz_map[tx_size][plane_type];
  aom_prob *eob_flag = cm->fc->eob_flag[tx_size][plane_type];
  MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
  const TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
  const SCAN_ORDER *const scan_order =
      get_scan(cm, tx_size, tx_type, is_inter_block(mbmi));
  const int16_t *scan = scan_order->scan;
  const int seg_eob = 16 << (tx_size << 1);
  int c = 0;
53
  int update_eob = -1;
54
  const int16_t *const dequant = xd->plane[plane].seg_dequant[mbmi->segment_id];
Angie Chiang's avatar
Angie Chiang committed
55
  const int shift = get_tx_scale(tx_size);
56 57 58 59 60 61 62 63 64
  const int bwl = b_width_log2_lookup[txsize_to_bsize[tx_size]] + 2;
  int cul_level = 0;
  unsigned int(*nz_map_count)[SIG_COEF_CONTEXTS][2];
  uint8_t txb_mask[32 * 32] = { 0 };

  nz_map_count = (counts) ? &counts->nz_map[tx_size][plane_type] : NULL;

  memset(tcoeffs, 0, sizeof(*tcoeffs) * seg_eob);

Angie Chiang's avatar
Angie Chiang committed
65 66 67 68 69
  int all_zero =
      aom_read(r, cm->fc->txb_skip[tx_size][txb_ctx->txb_skip_ctx], ACCT_STR);
  if (xd->counts)
    ++xd->counts->txb_skip[tx_size][txb_ctx->txb_skip_ctx][all_zero];

70
  *eob = 0;
Angie Chiang's avatar
Angie Chiang committed
71 72 73 74 75 76 77
  if (all_zero) {
    *max_scan_line = 0;
    return 0;
  }

  // av1_decode_tx_type(cm, xd, mbmi, r, plane, block);

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105
  for (c = 0; c < seg_eob; ++c) {
    int is_nz;
    int coeff_ctx = get_nz_map_ctx(tcoeffs, txb_mask, scan[c], bwl);
    int eob_ctx = get_eob_ctx(tcoeffs, scan[c], bwl);

    if (c < seg_eob - 1)
      is_nz = aom_read(r, nz_map[coeff_ctx], tx_size);
    else
      is_nz = 1;

    // set non-zero coefficient map.
    tcoeffs[scan[c]] = is_nz;

    if (c == seg_eob - 1) {
      ++c;
      break;
    }

    if (counts) ++(*nz_map_count)[coeff_ctx][is_nz];

    if (is_nz) {
      int is_eob = aom_read(r, eob_flag[eob_ctx], tx_size);
      if (counts) ++counts->eob_flag[tx_size][plane_type][eob_ctx][is_eob];
      if (is_eob) break;
    }
    txb_mask[scan[c]] = 1;
  }

106 107
  *eob = AOMMIN(seg_eob, c + 1);
  *max_scan_line = *eob;
108 109 110 111 112 113

  int i;
  for (i = 0; i < NUM_BASE_LEVELS; ++i) {
    aom_prob *coeff_base = cm->fc->coeff_base[tx_size][plane_type][i];

    update_eob = 0;
114
    for (c = *eob - 1; c >= 0; --c) {
115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185
      tran_low_t *v = &tcoeffs[scan[c]];
      int sign;
      int ctx;

      if (*v <= i) continue;

      ctx = get_base_ctx(tcoeffs, scan[c], bwl, i + 1);

      if (aom_read(r, coeff_base[ctx], tx_size)) {
        *v = i + 1;
        cul_level += i + 1;

        if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][1];

        if (c == 0) {
          int dc_sign_ctx = txb_ctx->dc_sign_ctx;
          sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
          if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
        } else {
          sign = aom_read_bit(r, ACCT_STR);
        }
        if (sign) *v = -(*v);
        continue;
      }
      *v = i + 2;
      if (counts) ++counts->coeff_base[tx_size][plane_type][i][ctx][0];

      // update the eob flag for coefficients with magnitude above 1.
      update_eob = AOMMAX(update_eob, c);
    }
  }

  for (c = update_eob; c >= 0; --c) {
    tran_low_t *v = &tcoeffs[scan[c]];
    int sign;
    int idx;
    int ctx;

    if (*v <= NUM_BASE_LEVELS) continue;

    if (c == 0) {
      int dc_sign_ctx = txb_ctx->dc_sign_ctx;
      sign = aom_read(r, cm->fc->dc_sign[plane_type][dc_sign_ctx], tx_size);
      if (counts) ++counts->dc_sign[plane_type][dc_sign_ctx][sign];
    } else {
      sign = aom_read_bit(r, ACCT_STR);
    }

    ctx = get_level_ctx(tcoeffs, scan[c], bwl);

    if (cm->fc->coeff_lps[tx_size][plane_type][ctx] == 0) exit(0);

    for (idx = 0; idx < COEFF_BASE_RANGE; ++idx) {
      if (aom_read(r, cm->fc->coeff_lps[tx_size][plane_type][ctx], tx_size)) {
        *v = (idx + 1 + NUM_BASE_LEVELS);
        if (sign) *v = -(*v);
        cul_level += abs(*v);

        if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][1];
        break;
      }
      if (counts) ++counts->coeff_lps[tx_size][plane_type][ctx][0];
    }
    if (idx < COEFF_BASE_RANGE) continue;

    // decode 0-th order Golomb code
    *v = read_golomb(r) + COEFF_BASE_RANGE + 1 + NUM_BASE_LEVELS;
    if (sign) *v = -(*v);
    cul_level += abs(*v);
  }

186
  for (c = 0; c < *eob; ++c) {
187 188 189 190 191 192 193 194 195 196 197 198 199 200
    int16_t dqv = (c == 0) ? dequant[0] : dequant[1];
    tran_low_t *v = &tcoeffs[scan[c]];
    int sign = (*v) < 0;
    *v = (abs(*v) * dqv) >> shift;
    if (sign) *v = -(*v);
  }

  cul_level = AOMMIN(63, cul_level);

  // DC value
  set_dc_sign(&cul_level, tcoeffs[0]);

  return cul_level;
}
Angie Chiang's avatar
Angie Chiang committed
201 202 203 204

uint8_t av1_read_coeffs_txb_facade(const AV1_COMMON *const cm, MACROBLOCKD *xd,
                                   aom_reader *r, int row, int col, int block,
                                   int plane, tran_low_t *tcoeffs,
205
                                   int16_t *max_scan_line, int *eob) {
Angie Chiang's avatar
Angie Chiang committed
206
  MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
207
  struct macroblockd_plane *pd = &xd->plane[plane];
Angie Chiang's avatar
Angie Chiang committed
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225

  const BLOCK_SIZE bsize = mbmi->sb_type;
#if CONFIG_CB4X4
#if CONFIG_CHROMA_2X2
  const BLOCK_SIZE plane_bsize = get_plane_block_size(bsize, pd);
#else
  const BLOCK_SIZE plane_bsize =
      AOMMAX(BLOCK_4X4, get_plane_block_size(bsize, pd));
#endif  // CONFIG_CHROMA_2X2
#else   // CONFIG_CB4X4
  const BLOCK_SIZE plane_bsize =
      get_plane_block_size(AOMMAX(BLOCK_8X8, bsize), pd);
#endif  // CONFIG_CB4X4

  TX_SIZE tx_size = get_tx_size(plane, xd);
  TXB_CTX txb_ctx;
  get_txb_ctx(plane_bsize, tx_size, plane, pd->above_context + col,
              pd->left_context + row, &txb_ctx);
226 227 228 229
  uint8_t cul_level = av1_read_coeffs_txb(cm, xd, r, block, plane, tcoeffs,
                                          &txb_ctx, max_scan_line, eob);
  av1_set_contexts(xd, pd, plane, tx_size, cul_level, col, row);
  return cul_level;
Angie Chiang's avatar
Angie Chiang committed
230
}