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txb_rdopt_utils.h (9031B)


      1 /*
      2 * Copyright (c) 2021, Alliance for Open Media. All rights reserved.
      3 *
      4 * This source code is subject to the terms of the BSD 2 Clause License and
      5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6 * was not distributed with this source code in the LICENSE file, you can
      7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8 * Media Patent License 1.0 was not distributed with this source code in the
      9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10 */
     11 
     12 #ifndef AOM_AV1_ENCODER_TXB_RDOPT_UTILS_H_
     13 #define AOM_AV1_ENCODER_TXB_RDOPT_UTILS_H_
     14 
     15 #include "av1/encoder/encodetxb.h"
     16 
     17 static const int golomb_bits_cost[32] = {
     18  0,       512,     512 * 3, 512 * 3, 512 * 5, 512 * 5, 512 * 5, 512 * 5,
     19  512 * 7, 512 * 7, 512 * 7, 512 * 7, 512 * 7, 512 * 7, 512 * 7, 512 * 7,
     20  512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9,
     21  512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9, 512 * 9
     22 };
     23 
     24 static const int golomb_cost_diff[32] = {
     25  0,       512, 512 * 2, 0, 512 * 2, 0, 0, 0, 512 * 2, 0, 0, 0, 0, 0, 0, 0,
     26  512 * 2, 0,   0,       0, 0,       0, 0, 0, 0,       0, 0, 0, 0, 0, 0, 0
     27 };
     28 
     29 // Look up table of individual cost of coefficient by its quantization level.
     30 // determined based on Laplacian distribution conditioned on estimated context
     31 static const int costLUT[15] = { -1143, 53,   545,  825,  1031,
     32                                 1209,  1393, 1577, 1763, 1947,
     33                                 2132,  2317, 2501, 2686, 2871 };
     34 
     35 static const int const_term = (1 << AV1_PROB_COST_SHIFT);
     36 
     37 static const int loge_par = ((14427 << AV1_PROB_COST_SHIFT) + 5000) / 10000;
     38 
     39 static inline int get_dqv(const int16_t *dequant, int coeff_idx,
     40                          const qm_val_t *iqmatrix) {
     41  int dqv = dequant[!!coeff_idx];
     42  if (iqmatrix != NULL)
     43    dqv =
     44        ((iqmatrix[coeff_idx] * dqv) + (1 << (AOM_QM_BITS - 1))) >> AOM_QM_BITS;
     45  return dqv;
     46 }
     47 
     48 static inline int64_t get_coeff_dist(tran_low_t tcoeff, tran_low_t dqcoeff,
     49                                     int shift, const qm_val_t *qmatrix,
     50                                     int coeff_idx) {
     51  int64_t diff = (tcoeff - dqcoeff) * (1 << shift);
     52  if (qmatrix == NULL) {
     53    return diff * diff;
     54  }
     55  // When AOM_DIST_METRIC_QM_PSNR is enabled, this mirrors the rate-distortion
     56  // computation done in av1_block_error_qm, improving visual quality.
     57  // The maximum value of `shift` is 2, `tcoeff` and `dqcoeff` are at most 22
     58  // bits, and AOM_QM_BITS is 5, so `diff` should fit in 29-bits. The
     59  // multiplication `diff * diff` then does not risk overflowing.
     60  diff *= qmatrix[coeff_idx];
     61  const int64_t error =
     62      (diff * diff + (1 << (2 * AOM_QM_BITS - 1))) >> (2 * AOM_QM_BITS);
     63  return error;
     64 }
     65 
     66 static int get_eob_cost(int eob, const LV_MAP_EOB_COST *txb_eob_costs,
     67                        const LV_MAP_COEFF_COST *txb_costs, TX_CLASS tx_class) {
     68  int eob_extra;
     69  const int eob_pt = av1_get_eob_pos_token(eob, &eob_extra);
     70  int eob_cost = 0;
     71  const int eob_multi_ctx = (tx_class == TX_CLASS_2D) ? 0 : 1;
     72  eob_cost = txb_eob_costs->eob_cost[eob_multi_ctx][eob_pt - 1];
     73 
     74  if (av1_eob_offset_bits[eob_pt] > 0) {
     75    const int eob_ctx = eob_pt - 3;
     76    const int eob_shift = av1_eob_offset_bits[eob_pt] - 1;
     77    const int bit = (eob_extra & (1 << eob_shift)) ? 1 : 0;
     78    eob_cost += txb_costs->eob_extra_cost[eob_ctx][bit];
     79    const int offset_bits = av1_eob_offset_bits[eob_pt];
     80    if (offset_bits > 1) eob_cost += av1_cost_literal(offset_bits - 1);
     81  }
     82  return eob_cost;
     83 }
     84 
     85 static inline int get_golomb_cost(int abs_qc) {
     86  if (abs_qc >= 1 + NUM_BASE_LEVELS + COEFF_BASE_RANGE) {
     87    const int r = abs_qc - COEFF_BASE_RANGE - NUM_BASE_LEVELS;
     88    const int length = get_msb(r) + 1;
     89    return av1_cost_literal(2 * length - 1);
     90  }
     91  return 0;
     92 }
     93 
     94 static inline int get_br_cost(tran_low_t level, const int *coeff_lps) {
     95  const int base_range = AOMMIN(level - 1 - NUM_BASE_LEVELS, COEFF_BASE_RANGE);
     96  return coeff_lps[base_range] + get_golomb_cost(level);
     97 }
     98 
     99 static inline int get_br_cost_with_diff(tran_low_t level, const int *coeff_lps,
    100                                        int *diff) {
    101  const int base_range = AOMMIN(level - 1 - NUM_BASE_LEVELS, COEFF_BASE_RANGE);
    102  int golomb_bits = 0;
    103  if (level <= COEFF_BASE_RANGE + 1 + NUM_BASE_LEVELS)
    104    *diff += coeff_lps[base_range + COEFF_BASE_RANGE + 1];
    105 
    106  if (level >= COEFF_BASE_RANGE + 1 + NUM_BASE_LEVELS) {
    107    int r = level - COEFF_BASE_RANGE - NUM_BASE_LEVELS;
    108    if (r < 32) {
    109      golomb_bits = golomb_bits_cost[r];
    110      *diff += golomb_cost_diff[r];
    111    } else {
    112      golomb_bits = get_golomb_cost(level);
    113      *diff += (r & (r - 1)) == 0 ? 1024 : 0;
    114    }
    115  }
    116 
    117  return coeff_lps[base_range] + golomb_bits;
    118 }
    119 
    120 static AOM_FORCE_INLINE int get_two_coeff_cost_simple(
    121    int ci, tran_low_t abs_qc, int coeff_ctx,
    122    const LV_MAP_COEFF_COST *txb_costs, int bhl, TX_CLASS tx_class,
    123    const uint8_t *levels, int *cost_low) {
    124  // this simple version assumes the coeff's scan_idx is not DC (scan_idx != 0)
    125  // and not the last (scan_idx != eob - 1)
    126  assert(ci > 0);
    127  int cost = txb_costs->base_cost[coeff_ctx][AOMMIN(abs_qc, 3)];
    128  int diff = 0;
    129  if (abs_qc <= 3) diff = txb_costs->base_cost[coeff_ctx][abs_qc + 4];
    130  if (abs_qc) {
    131    cost += av1_cost_literal(1);
    132    if (abs_qc > NUM_BASE_LEVELS) {
    133      const int br_ctx = get_br_ctx(levels, ci, bhl, tx_class);
    134      int brcost_diff = 0;
    135      cost += get_br_cost_with_diff(abs_qc, txb_costs->lps_cost[br_ctx],
    136                                    &brcost_diff);
    137      diff += brcost_diff;
    138    }
    139  }
    140  *cost_low = cost - diff;
    141 
    142  return cost;
    143 }
    144 
    145 static inline int get_coeff_cost_eob(int ci, tran_low_t abs_qc, int sign,
    146                                     int coeff_ctx, int dc_sign_ctx,
    147                                     const LV_MAP_COEFF_COST *txb_costs,
    148                                     int bhl, TX_CLASS tx_class) {
    149  int cost = 0;
    150  cost += txb_costs->base_eob_cost[coeff_ctx][AOMMIN(abs_qc, 3) - 1];
    151  if (abs_qc != 0) {
    152    if (ci == 0) {
    153      cost += txb_costs->dc_sign_cost[dc_sign_ctx][sign];
    154    } else {
    155      cost += av1_cost_literal(1);
    156    }
    157    if (abs_qc > NUM_BASE_LEVELS) {
    158      int br_ctx;
    159      br_ctx = get_br_ctx_eob(ci, bhl, tx_class);
    160      cost += get_br_cost(abs_qc, txb_costs->lps_cost[br_ctx]);
    161    }
    162  }
    163  return cost;
    164 }
    165 
    166 static inline int get_coeff_cost_general(int is_last, int ci, tran_low_t abs_qc,
    167                                         int sign, int coeff_ctx,
    168                                         int dc_sign_ctx,
    169                                         const LV_MAP_COEFF_COST *txb_costs,
    170                                         int bhl, TX_CLASS tx_class,
    171                                         const uint8_t *levels) {
    172  int cost = 0;
    173  if (is_last) {
    174    cost += txb_costs->base_eob_cost[coeff_ctx][AOMMIN(abs_qc, 3) - 1];
    175  } else {
    176    cost += txb_costs->base_cost[coeff_ctx][AOMMIN(abs_qc, 3)];
    177  }
    178  if (abs_qc != 0) {
    179    if (ci == 0) {
    180      cost += txb_costs->dc_sign_cost[dc_sign_ctx][sign];
    181    } else {
    182      cost += av1_cost_literal(1);
    183    }
    184    if (abs_qc > NUM_BASE_LEVELS) {
    185      int br_ctx;
    186      if (is_last)
    187        br_ctx = get_br_ctx_eob(ci, bhl, tx_class);
    188      else
    189        br_ctx = get_br_ctx(levels, ci, bhl, tx_class);
    190      cost += get_br_cost(abs_qc, txb_costs->lps_cost[br_ctx]);
    191    }
    192  }
    193  return cost;
    194 }
    195 
    196 static inline void get_qc_dqc_low(tran_low_t abs_qc, int sign, int dqv,
    197                                  int shift, tran_low_t *qc_low,
    198                                  tran_low_t *dqc_low) {
    199  tran_low_t abs_qc_low = abs_qc - 1;
    200  *qc_low = (-sign ^ abs_qc_low) + sign;
    201  assert((sign ? -abs_qc_low : abs_qc_low) == *qc_low);
    202  tran_low_t abs_dqc_low = (abs_qc_low * dqv) >> shift;
    203  *dqc_low = (-sign ^ abs_dqc_low) + sign;
    204  assert((sign ? -abs_dqc_low : abs_dqc_low) == *dqc_low);
    205 }
    206 
    207 static inline void update_coeff_eob_fast(int *eob, int shift,
    208                                         const int16_t *dequant_ptr,
    209                                         const int16_t *scan,
    210                                         const tran_low_t *coeff_ptr,
    211                                         tran_low_t *qcoeff_ptr,
    212                                         tran_low_t *dqcoeff_ptr) {
    213  // TODO(sarahparker) make this work for aomqm
    214  int eob_out = *eob;
    215  int zbin[2] = { dequant_ptr[0] + ROUND_POWER_OF_TWO(dequant_ptr[0] * 70, 7),
    216                  dequant_ptr[1] + ROUND_POWER_OF_TWO(dequant_ptr[1] * 70, 7) };
    217 
    218  for (int i = *eob - 1; i >= 0; i--) {
    219    const int rc = scan[i];
    220    const int qcoeff = qcoeff_ptr[rc];
    221    const int coeff = coeff_ptr[rc];
    222    const int coeff_sign = AOMSIGN(coeff);
    223    int64_t abs_coeff = (coeff ^ coeff_sign) - coeff_sign;
    224 
    225    if (((abs_coeff << (1 + shift)) < zbin[rc != 0]) || (qcoeff == 0)) {
    226      eob_out--;
    227      qcoeff_ptr[rc] = 0;
    228      dqcoeff_ptr[rc] = 0;
    229    } else {
    230      break;
    231    }
    232  }
    233 
    234  *eob = eob_out;
    235 }
    236 #endif  // AOM_AV1_ENCODER_TXB_RDOPT_UTILS_H_