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aq_cyclicrefresh.c (29681B)


      1 /*
      2 * Copyright (c) 2016, 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 #include <limits.h>
     13 #include <math.h>
     14 
     15 #include "av1/common/pred_common.h"
     16 #include "av1/common/seg_common.h"
     17 #include "av1/encoder/aq_cyclicrefresh.h"
     18 #include "av1/encoder/encoder_utils.h"
     19 #include "av1/encoder/ratectrl.h"
     20 #include "av1/encoder/segmentation.h"
     21 #include "av1/encoder/tokenize.h"
     22 #include "aom_dsp/aom_dsp_common.h"
     23 
     24 CYCLIC_REFRESH *av1_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
     25  CYCLIC_REFRESH *const cr = aom_calloc(1, sizeof(*cr));
     26  if (cr == NULL) return NULL;
     27 
     28  cr->map = aom_calloc(mi_rows * mi_cols, sizeof(*cr->map));
     29  cr->counter_encode_maxq_scene_change = 0;
     30  cr->percent_refresh_adjustment = 5;
     31  cr->rate_ratio_qdelta_adjustment = 0.25;
     32  if (cr->map == NULL) {
     33    av1_cyclic_refresh_free(cr);
     34    return NULL;
     35  }
     36  return cr;
     37 }
     38 
     39 void av1_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
     40  if (cr != NULL) {
     41    aom_free(cr->map);
     42    aom_free(cr);
     43  }
     44 }
     45 
     46 // Check if this coding block, of size bsize, should be considered for refresh
     47 // (lower-qp coding). Decision can be based on various factors, such as
     48 // size of the coding block (i.e., below min_block size rejected), coding
     49 // mode, and rate/distortion.
     50 static int candidate_refresh_aq(const CYCLIC_REFRESH *cr,
     51                                const MB_MODE_INFO *mbmi, int64_t rate,
     52                                int64_t dist, BLOCK_SIZE bsize,
     53                                int noise_level) {
     54  MV mv = mbmi->mv[0].as_mv;
     55  int is_compound = has_second_ref(mbmi);
     56  // Reject the block for lower-qp coding for non-compound mode if
     57  // projected distortion is above the threshold, and any of the following
     58  // is true:
     59  // 1) mode uses large mv
     60  // 2) mode is an intra-mode
     61  // Otherwise accept for refresh.
     62  if (!is_compound && dist > cr->thresh_dist_sb &&
     63      (mv.row > cr->motion_thresh || mv.row < -cr->motion_thresh ||
     64       mv.col > cr->motion_thresh || mv.col < -cr->motion_thresh ||
     65       !is_inter_block(mbmi)))
     66    return CR_SEGMENT_ID_BASE;
     67  else if ((is_compound && noise_level < kMedium) ||
     68           (bsize >= BLOCK_16X16 && rate < cr->thresh_rate_sb &&
     69            is_inter_block(mbmi) && mbmi->mv[0].as_int == 0 &&
     70            cr->rate_boost_fac > 10))
     71    // More aggressive delta-q for bigger blocks with zero motion.
     72    return CR_SEGMENT_ID_BOOST2;
     73  else
     74    return CR_SEGMENT_ID_BOOST1;
     75 }
     76 
     77 // Compute delta-q for the segment.
     78 static int compute_deltaq(const AV1_COMP *cpi, int q, double rate_factor) {
     79  const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
     80  int deltaq = av1_compute_qdelta_by_rate(
     81      cpi, cpi->common.current_frame.frame_type, q, rate_factor);
     82  if ((-deltaq) > cr->max_qdelta_perc * q / 100) {
     83    deltaq = -cr->max_qdelta_perc * q / 100;
     84  }
     85  return deltaq;
     86 }
     87 
     88 int av1_cyclic_refresh_estimate_bits_at_q(const AV1_COMP *cpi,
     89                                          double correction_factor) {
     90  const AV1_COMMON *const cm = &cpi->common;
     91  const int base_qindex = cm->quant_params.base_qindex;
     92  const CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
     93  const int mbs = cm->mi_params.MBs;
     94  const int num4x4bl = mbs << 4;
     95  // Weight for non-base segments: use actual number of blocks refreshed in
     96  // previous/just encoded frame. Note number of blocks here is in 4x4 units.
     97  double weight_segment1 = (double)cr->actual_num_seg1_blocks / num4x4bl;
     98  double weight_segment2 = (double)cr->actual_num_seg2_blocks / num4x4bl;
     99  if (cpi->rc.rtc_external_ratectrl) {
    100    weight_segment1 = (double)(cr->percent_refresh * cm->mi_params.mi_rows *
    101                               cm->mi_params.mi_cols / 100) /
    102                      num4x4bl;
    103    weight_segment2 = 0;
    104  }
    105  // Take segment weighted average for estimated bits.
    106  const int estimated_bits = (int)round(
    107      (1.0 - weight_segment1 - weight_segment2) *
    108          av1_estimate_bits_at_q(cpi, base_qindex, correction_factor) +
    109      weight_segment1 *
    110          av1_estimate_bits_at_q(cpi, base_qindex + cr->qindex_delta[1],
    111                                 correction_factor) +
    112      weight_segment2 *
    113          av1_estimate_bits_at_q(cpi, base_qindex + cr->qindex_delta[2],
    114                                 correction_factor));
    115  return estimated_bits;
    116 }
    117 
    118 int av1_cyclic_refresh_rc_bits_per_mb(const AV1_COMP *cpi, int i,
    119                                      double correction_factor) {
    120  const AV1_COMMON *const cm = &cpi->common;
    121  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    122  int bits_per_mb;
    123  int num4x4bl = cm->mi_params.MBs << 4;
    124  // Weight for segment prior to encoding: take the average of the target
    125  // number for the frame to be encoded and the actual from the previous frame.
    126  double weight_segment =
    127      (double)((cr->target_num_seg_blocks + cr->actual_num_seg1_blocks +
    128                cr->actual_num_seg2_blocks) >>
    129               1) /
    130      num4x4bl;
    131  if (cpi->rc.rtc_external_ratectrl) {
    132    weight_segment = (double)((cr->target_num_seg_blocks +
    133                               cr->percent_refresh * cm->mi_params.mi_rows *
    134                                   cm->mi_params.mi_cols / 100) >>
    135                              1) /
    136                     num4x4bl;
    137  }
    138  // Compute delta-q corresponding to qindex i.
    139  int deltaq = compute_deltaq(cpi, i, cr->rate_ratio_qdelta);
    140  const int accurate_estimate = cpi->sf.hl_sf.accurate_bit_estimate;
    141  // Take segment weighted average for bits per mb.
    142  bits_per_mb = (int)round(
    143      (1.0 - weight_segment) *
    144          av1_rc_bits_per_mb(cpi, cm->current_frame.frame_type, i,
    145                             correction_factor, accurate_estimate) +
    146      weight_segment * av1_rc_bits_per_mb(cpi, cm->current_frame.frame_type,
    147                                          i + deltaq, correction_factor,
    148                                          accurate_estimate));
    149  return bits_per_mb;
    150 }
    151 
    152 void av1_cyclic_reset_segment_skip(const AV1_COMP *cpi, MACROBLOCK *const x,
    153                                   int mi_row, int mi_col, BLOCK_SIZE bsize,
    154                                   RUN_TYPE dry_run) {
    155  int cdf_num;
    156  const AV1_COMMON *const cm = &cpi->common;
    157  MACROBLOCKD *const xd = &x->e_mbd;
    158  MB_MODE_INFO *const mbmi = xd->mi[0];
    159  const int prev_segment_id = mbmi->segment_id;
    160  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    161  const int bw = mi_size_wide[bsize];
    162  const int bh = mi_size_high[bsize];
    163  const int xmis = AOMMIN(cm->mi_params.mi_cols - mi_col, bw);
    164  const int ymis = AOMMIN(cm->mi_params.mi_rows - mi_row, bh);
    165 
    166  assert(cm->seg.enabled);
    167 
    168  if (!cr->skip_over4x4 && !cpi->roi.reference_enabled) {
    169    mbmi->segment_id =
    170        av1_get_spatial_seg_pred(cm, xd, &cdf_num, cr->skip_over4x4);
    171    if (prev_segment_id != mbmi->segment_id) {
    172      const int block_index = mi_row * cm->mi_params.mi_cols + mi_col;
    173      const int mi_stride = cm->mi_params.mi_cols;
    174      const uint8_t segment_id = mbmi->segment_id;
    175      for (int mi_y = 0; mi_y < ymis; mi_y++) {
    176        const int map_offset = block_index + mi_y * mi_stride;
    177        memset(&cr->map[map_offset], 0, xmis);
    178        memset(&cpi->enc_seg.map[map_offset], segment_id, xmis);
    179        memset(&cm->cur_frame->seg_map[map_offset], segment_id, xmis);
    180      }
    181    }
    182  }
    183  if (!dry_run) {
    184    if (cyclic_refresh_segment_id(prev_segment_id) == CR_SEGMENT_ID_BOOST1)
    185      x->actual_num_seg1_blocks -= xmis * ymis;
    186    else if (cyclic_refresh_segment_id(prev_segment_id) == CR_SEGMENT_ID_BOOST2)
    187      x->actual_num_seg2_blocks -= xmis * ymis;
    188  }
    189 }
    190 
    191 void av1_cyclic_refresh_update_segment(const AV1_COMP *cpi, MACROBLOCK *const x,
    192                                       int mi_row, int mi_col, BLOCK_SIZE bsize,
    193                                       int64_t rate, int64_t dist, int skip,
    194                                       RUN_TYPE dry_run) {
    195  const AV1_COMMON *const cm = &cpi->common;
    196  MACROBLOCKD *const xd = &x->e_mbd;
    197  MB_MODE_INFO *const mbmi = xd->mi[0];
    198  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    199  const int bw = mi_size_wide[bsize];
    200  const int bh = mi_size_high[bsize];
    201  const int xmis = AOMMIN(cm->mi_params.mi_cols - mi_col, bw);
    202  const int ymis = AOMMIN(cm->mi_params.mi_rows - mi_row, bh);
    203  const int block_index = mi_row * cm->mi_params.mi_cols + mi_col;
    204  int noise_level = 0;
    205  if (cpi->noise_estimate.enabled) noise_level = cpi->noise_estimate.level;
    206  const int refresh_this_block =
    207      candidate_refresh_aq(cr, mbmi, rate, dist, bsize, noise_level);
    208  int sh = cpi->cyclic_refresh->skip_over4x4 ? 2 : 1;
    209  // Default is to not update the refresh map.
    210  int new_map_value = cr->map[block_index];
    211 
    212  // If this block is labeled for refresh, check if we should reset the
    213  // segment_id.
    214  if (cyclic_refresh_segment_id_boosted(mbmi->segment_id)) {
    215    mbmi->segment_id = refresh_this_block;
    216    // Reset segment_id if will be skipped.
    217    if (skip) mbmi->segment_id = CR_SEGMENT_ID_BASE;
    218  }
    219  const uint8_t segment_id = mbmi->segment_id;
    220 
    221  // Update the cyclic refresh map, to be used for setting segmentation map
    222  // for the next frame. If the block  will be refreshed this frame, mark it
    223  // as clean. The magnitude of the -ve influences how long before we consider
    224  // it for refresh again.
    225  if (cyclic_refresh_segment_id_boosted(segment_id)) {
    226    new_map_value = -cr->time_for_refresh;
    227  } else if (refresh_this_block) {
    228    // Else if it is accepted as candidate for refresh, and has not already
    229    // been refreshed (marked as 1) then mark it as a candidate for cleanup
    230    // for future time (marked as 0), otherwise don't update it.
    231    if (cr->map[block_index] == 1) new_map_value = 0;
    232  } else {
    233    // Leave it marked as block that is not candidate for refresh.
    234    new_map_value = 1;
    235  }
    236 
    237  // Update entries in the cyclic refresh map with new_map_value, and
    238  // copy mbmi->segment_id into global segmentation map.
    239  const int mi_stride = cm->mi_params.mi_cols;
    240  for (int mi_y = 0; mi_y < ymis; mi_y += sh) {
    241    const int map_offset = block_index + mi_y * mi_stride;
    242    memset(&cr->map[map_offset], new_map_value, xmis);
    243    memset(&cpi->enc_seg.map[map_offset], segment_id, xmis);
    244    memset(&cm->cur_frame->seg_map[map_offset], segment_id, xmis);
    245  }
    246 
    247  // Accumulate cyclic refresh update counters.
    248  if (!dry_run) {
    249    if (cyclic_refresh_segment_id(segment_id) == CR_SEGMENT_ID_BOOST1)
    250      x->actual_num_seg1_blocks += xmis * ymis;
    251    else if (cyclic_refresh_segment_id(segment_id) == CR_SEGMENT_ID_BOOST2)
    252      x->actual_num_seg2_blocks += xmis * ymis;
    253  }
    254 }
    255 
    256 // Initializes counters used for cyclic refresh.
    257 void av1_init_cyclic_refresh_counters(MACROBLOCK *const x) {
    258  x->actual_num_seg1_blocks = 0;
    259  x->actual_num_seg2_blocks = 0;
    260 }
    261 
    262 // Accumulate cyclic refresh counters.
    263 void av1_accumulate_cyclic_refresh_counters(
    264    CYCLIC_REFRESH *const cyclic_refresh, const MACROBLOCK *const x) {
    265  cyclic_refresh->actual_num_seg1_blocks += x->actual_num_seg1_blocks;
    266  cyclic_refresh->actual_num_seg2_blocks += x->actual_num_seg2_blocks;
    267 }
    268 
    269 void av1_cyclic_refresh_set_golden_update(AV1_COMP *const cpi) {
    270  RATE_CONTROL *const rc = &cpi->rc;
    271  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
    272  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    273  // Set minimum gf_interval for GF update to a multiple of the refresh period,
    274  // with some max limit. Depending on past encoding stats, GF flag may be
    275  // reset and update may not occur until next baseline_gf_interval.
    276  const int gf_length_mult[2] = { 8, 4 };
    277  if (cr->percent_refresh > 0)
    278    p_rc->baseline_gf_interval =
    279        AOMMIN(gf_length_mult[cpi->sf.rt_sf.gf_length_lvl] *
    280                   (100 / cr->percent_refresh),
    281               MAX_GF_INTERVAL_RT);
    282  else
    283    p_rc->baseline_gf_interval = FIXED_GF_INTERVAL_RT;
    284  if (rc->avg_frame_low_motion && rc->avg_frame_low_motion < 40)
    285    p_rc->baseline_gf_interval = 16;
    286 }
    287 
    288 // Update the segmentation map, and related quantities: cyclic refresh map,
    289 // refresh sb_index, and target number of blocks to be refreshed.
    290 // The map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or to
    291 // 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock.
    292 // Blocks labeled as BOOST1 may later get set to BOOST2 (during the
    293 // encoding of the superblock).
    294 static void cyclic_refresh_update_map(AV1_COMP *const cpi) {
    295  AV1_COMMON *const cm = &cpi->common;
    296  const CommonModeInfoParams *const mi_params = &cm->mi_params;
    297  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    298  unsigned char *const seg_map = cpi->enc_seg.map;
    299  unsigned char *const active_map_4x4 = cpi->active_map.map;
    300  int i, block_count, bl_index, sb_rows, sb_cols, sbs_in_frame;
    301  int xmis, ymis, x, y;
    302  uint64_t sb_sad = 0;
    303  uint64_t thresh_sad_low = 0;
    304  uint64_t thresh_sad = INT64_MAX;
    305  const int mi_rows = mi_params->mi_rows, mi_cols = mi_params->mi_cols;
    306  const int mi_stride = mi_cols;
    307  // Don't set seg_map to 0 if active_maps is enabled. Active_maps will set
    308  // seg_map to either 7 or 0 (AM_SEGMENT_ID_INACTIVE/ACTIVE), and cyclic
    309  // refresh set below (segment 1 or 2) will only be set for ACTIVE blocks.
    310  if (!cpi->active_map.enabled) {
    311    memset(seg_map, CR_SEGMENT_ID_BASE, mi_rows * mi_cols);
    312  }
    313  sb_cols = (mi_cols + cm->seq_params->mib_size - 1) / cm->seq_params->mib_size;
    314  sb_rows = (mi_rows + cm->seq_params->mib_size - 1) / cm->seq_params->mib_size;
    315  sbs_in_frame = sb_cols * sb_rows;
    316  // Number of target blocks to get the q delta (segment 1).
    317  block_count = cr->percent_refresh * mi_rows * mi_cols / 100;
    318  // Set the segmentation map: cycle through the superblocks, starting at
    319  // cr->mb_index, and stopping when either block_count blocks have been found
    320  // to be refreshed, or we have passed through whole frame.
    321  if (cr->sb_index >= sbs_in_frame) cr->sb_index = 0;
    322  assert(cr->sb_index < sbs_in_frame);
    323  i = cr->sb_index;
    324  cr->last_sb_index = cr->sb_index;
    325  cr->target_num_seg_blocks = 0;
    326  do {
    327    int sum_map = 0;
    328    // Get the mi_row/mi_col corresponding to superblock index i.
    329    int sb_row_index = (i / sb_cols);
    330    int sb_col_index = i - sb_row_index * sb_cols;
    331    int mi_row = sb_row_index * cm->seq_params->mib_size;
    332    int mi_col = sb_col_index * cm->seq_params->mib_size;
    333    assert(mi_row >= 0 && mi_row < mi_rows);
    334    assert(mi_col >= 0 && mi_col < mi_cols);
    335    bl_index = mi_row * mi_stride + mi_col;
    336    // Loop through all MI blocks in superblock and update map.
    337    xmis = AOMMIN(mi_cols - mi_col, cm->seq_params->mib_size);
    338    ymis = AOMMIN(mi_rows - mi_row, cm->seq_params->mib_size);
    339    if (cr->use_block_sad_scene_det && cpi->rc.frames_since_key > 30 &&
    340        cr->counter_encode_maxq_scene_change > 30 &&
    341        cpi->src_sad_blk_64x64 != NULL &&
    342        cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1) {
    343      sb_sad = cpi->src_sad_blk_64x64[sb_col_index + sb_cols * sb_row_index];
    344      int scale = (cm->width * cm->height < 640 * 360) ? 6 : 8;
    345      int scale_low = 2;
    346      thresh_sad = (scale * 64 * 64);
    347      thresh_sad_low = (scale_low * 64 * 64);
    348      // For temporal layers: the base temporal layer (temporal_layer_id = 0)
    349      // has larger frame separation (2 or 4 frames apart), so use larger sad
    350      // thresholds to compensate for larger frame sad. The larger thresholds
    351      // also increase the amount of refresh, which is needed for the base
    352      // temporal layer.
    353      if (cpi->svc.number_temporal_layers > 1 &&
    354          cpi->svc.temporal_layer_id == 0) {
    355        thresh_sad <<= 4;
    356        thresh_sad_low <<= 2;
    357      }
    358    }
    359    // cr_map only needed at 8x8 blocks.
    360    for (y = 0; y < ymis; y += 2) {
    361      for (x = 0; x < xmis; x += 2) {
    362        const int bl_index2 = bl_index + y * mi_stride + x;
    363        // If the block is as a candidate for clean up then mark it
    364        // for possible boost/refresh (segment 1). The segment id may get
    365        // reset to 0 later if block gets coded anything other than low motion.
    366        // If the block_sad (sb_sad) is very low label it for refresh anyway.
    367        // If active_maps is enabled, only allow for setting on ACTIVE blocks.
    368        if ((cr->map[bl_index2] == 0 || sb_sad < thresh_sad_low) &&
    369            (!cpi->active_map.enabled ||
    370             active_map_4x4[bl_index2] == AM_SEGMENT_ID_ACTIVE)) {
    371          sum_map += 4;
    372        } else if (cr->map[bl_index2] < 0) {
    373          cr->map[bl_index2]++;
    374        }
    375      }
    376    }
    377    // Enforce constant segment over superblock.
    378    // If segment is at least half of superblock, set to 1.
    379    // Enforce that block sad (sb_sad) is not too high.
    380    if (sum_map >= (xmis * ymis) >> 1 && sb_sad < thresh_sad) {
    381      set_segment_id(seg_map, bl_index, xmis, ymis, mi_stride,
    382                     CR_SEGMENT_ID_BOOST1);
    383      cr->target_num_seg_blocks += xmis * ymis;
    384    }
    385    i++;
    386    if (i == sbs_in_frame) {
    387      i = 0;
    388    }
    389  } while (cr->target_num_seg_blocks < block_count && i != cr->sb_index);
    390  cr->sb_index = i;
    391  if (cr->target_num_seg_blocks == 0) {
    392    // Disable segmentation, seg_map is already set to 0 above.
    393    // Don't disable if active_map is being used.
    394    if (!cpi->active_map.enabled) av1_disable_segmentation(&cm->seg);
    395  }
    396 }
    397 
    398 static int is_scene_change_detected(AV1_COMP *const cpi) {
    399  return cpi->rc.high_source_sad;
    400 }
    401 
    402 // Set cyclic refresh parameters.
    403 void av1_cyclic_refresh_update_parameters(AV1_COMP *const cpi) {
    404  // TODO(marpan): Parameters need to be tuned.
    405  const RATE_CONTROL *const rc = &cpi->rc;
    406  const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
    407  const AV1_COMMON *const cm = &cpi->common;
    408  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    409  SVC *const svc = &cpi->svc;
    410  const int qp_thresh = AOMMAX(16, rc->best_quality + 4);
    411  const int qp_max_thresh = 118 * MAXQ >> 7;
    412  const int scene_change_detected = is_scene_change_detected(cpi);
    413  const int is_screen_content =
    414      (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN);
    415 
    416  // A scene change or key frame marks the start of a cyclic refresh cycle.
    417  const int frames_since_scene_change =
    418      (cpi->ppi->use_svc || !is_screen_content)
    419          ? cpi->rc.frames_since_key
    420          : AOMMIN(cpi->rc.frames_since_key,
    421                   cr->counter_encode_maxq_scene_change);
    422 
    423  // Cases to reset the cyclic refresh adjustment parameters.
    424  if (frame_is_intra_only(cm) || scene_change_detected ||
    425      cpi->ppi->rtc_ref.bias_recovery_frame) {
    426    // Reset adaptive elements for intra only frames and scene changes.
    427    cr->percent_refresh_adjustment = 5;
    428    cr->rate_ratio_qdelta_adjustment = 0.25;
    429  }
    430 
    431  // Although this segment feature for RTC is only used for
    432  // blocks >= 8X8, for more efficient coding of the seg map
    433  // cur_frame->seg_map needs to set at 4x4 along with the
    434  // function av1_cyclic_reset_segment_skip(). Skipping over
    435  // 4x4 will therefore have small bdrate loss (~0.2%), so
    436  // we use it only for speed > 9 for now.
    437  cr->skip_over4x4 = (cpi->oxcf.speed > 9 && !cpi->roi.enabled) ? 1 : 0;
    438 
    439  // should we enable cyclic refresh on this frame.
    440  cr->apply_cyclic_refresh = 1;
    441  if (frame_is_intra_only(cm) || is_lossless_requested(&cpi->oxcf.rc_cfg) ||
    442      cpi->roi.enabled || cpi->rc.high_motion_content_screen_rtc ||
    443      scene_change_detected || svc->temporal_layer_id > 0 ||
    444      svc->prev_number_spatial_layers != svc->number_spatial_layers ||
    445      p_rc->avg_frame_qindex[INTER_FRAME] < qp_thresh ||
    446      (svc->number_spatial_layers > 1 &&
    447       svc->layer_context[svc->temporal_layer_id].is_key_frame) ||
    448      (frames_since_scene_change > 20 &&
    449       p_rc->avg_frame_qindex[INTER_FRAME] > qp_max_thresh) ||
    450      (rc->avg_frame_low_motion && rc->avg_frame_low_motion < 30 &&
    451       frames_since_scene_change > 40) ||
    452      cpi->ppi->rtc_ref.bias_recovery_frame) {
    453    cr->apply_cyclic_refresh = 0;
    454    return;
    455  }
    456 
    457  // Increase the amount of refresh for #temporal_layers > 2
    458  if (svc->number_temporal_layers > 2)
    459    cr->percent_refresh = 15;
    460  else
    461    cr->percent_refresh = 10 + cr->percent_refresh_adjustment;
    462 
    463  if (cpi->active_map.enabled) {
    464    // Scale down the percent_refresh to target the active blocks only.
    465    cr->percent_refresh =
    466        cr->percent_refresh * (100 - cpi->rc.percent_blocks_inactive) / 100;
    467    if (cr->percent_refresh == 0) {
    468      cr->apply_cyclic_refresh = 0;
    469    }
    470  }
    471 
    472  cr->max_qdelta_perc = 60;
    473  cr->time_for_refresh = 0;
    474  cr->use_block_sad_scene_det =
    475      (cpi->oxcf.tune_cfg.content != AOM_CONTENT_SCREEN &&
    476       cm->seq_params->sb_size == BLOCK_64X64)
    477          ? 1
    478          : 0;
    479  cr->motion_thresh = 32;
    480  cr->rate_boost_fac =
    481      (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN) ? 10 : 15;
    482 
    483  // Use larger delta-qp (increase rate_ratio_qdelta) for first few
    484  // refresh cycles after a key frame (svc) or scene change (non svc).
    485  // For non svc screen content, after a scene change gradually reduce
    486  // this boost and supress it further if either of the previous two
    487  // frames overshot.
    488  if (cr->percent_refresh > 0) {
    489    if (cpi->ppi->use_svc || !is_screen_content) {
    490      if (frames_since_scene_change <
    491          ((4 * svc->number_temporal_layers) * (100 / cr->percent_refresh))) {
    492        cr->rate_ratio_qdelta = 3.0 + cr->rate_ratio_qdelta_adjustment;
    493      } else {
    494        cr->rate_ratio_qdelta = 2.25 + cr->rate_ratio_qdelta_adjustment;
    495      }
    496    } else {
    497      double distance_from_sc_factor =
    498          AOMMIN(0.75, (int)(frames_since_scene_change / 10) * 0.1);
    499      cr->rate_ratio_qdelta =
    500          3.0 + cr->rate_ratio_qdelta_adjustment - distance_from_sc_factor;
    501      if ((frames_since_scene_change < 10) &&
    502          ((cpi->rc.rc_1_frame < 0) || (cpi->rc.rc_2_frame < 0))) {
    503        cr->rate_ratio_qdelta -= 0.25;
    504      }
    505    }
    506  } else {
    507    cr->rate_ratio_qdelta = 2.25 + cr->rate_ratio_qdelta_adjustment;
    508  }
    509  // Adjust some parameters for low resolutions.
    510  if (cm->width * cm->height <= 352 * 288) {
    511    if (cpi->svc.number_temporal_layers > 1) {
    512      cr->motion_thresh = 32;
    513      cr->rate_boost_fac = 13;
    514    } else {
    515      if (rc->avg_frame_bandwidth < 3000) {
    516        cr->motion_thresh = 16;
    517        cr->rate_boost_fac = 13;
    518      } else {
    519        cr->max_qdelta_perc = 50;
    520        cr->rate_ratio_qdelta = AOMMAX(cr->rate_ratio_qdelta, 2.0);
    521      }
    522    }
    523  }
    524  if (cpi->oxcf.rc_cfg.mode == AOM_VBR) {
    525    // To be adjusted for VBR mode, e.g., based on gf period and boost.
    526    // For now use smaller qp-delta (than CBR), no second boosted seg, and
    527    // turn-off (no refresh) on golden refresh (since it's already boosted).
    528    cr->percent_refresh = 10;
    529    cr->rate_ratio_qdelta = 1.5;
    530    cr->rate_boost_fac = 10;
    531    if (cpi->refresh_frame.golden_frame) {
    532      cr->percent_refresh = 0;
    533      cr->rate_ratio_qdelta = 1.0;
    534    }
    535  }
    536  if (rc->rtc_external_ratectrl) {
    537    cr->actual_num_seg1_blocks = cr->percent_refresh * cm->mi_params.mi_rows *
    538                                 cm->mi_params.mi_cols / 100;
    539    cr->actual_num_seg2_blocks = 0;
    540  }
    541 }
    542 
    543 static void cyclic_refresh_reset_resize(AV1_COMP *const cpi) {
    544  const AV1_COMMON *const cm = &cpi->common;
    545  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    546  memset(cr->map, 0, cm->mi_params.mi_rows * cm->mi_params.mi_cols);
    547  cr->sb_index = 0;
    548  cr->last_sb_index = 0;
    549  cpi->refresh_frame.golden_frame = true;
    550  cr->apply_cyclic_refresh = 0;
    551  cr->counter_encode_maxq_scene_change = 0;
    552  cr->percent_refresh_adjustment = 5;
    553  cr->rate_ratio_qdelta_adjustment = 0.25;
    554 }
    555 
    556 // Setup cyclic background refresh: set delta q and segmentation map.
    557 void av1_cyclic_refresh_setup(AV1_COMP *const cpi) {
    558  AV1_COMMON *const cm = &cpi->common;
    559  const RATE_CONTROL *const rc = &cpi->rc;
    560  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    561  struct segmentation *const seg = &cm->seg;
    562  const int scene_change_detected = is_scene_change_detected(cpi);
    563  const GF_GROUP *const gf_group = &cpi->ppi->gf_group;
    564  const int boost_index = AOMMIN(15, (cpi->ppi->p_rc.gfu_boost / 100));
    565  const int layer_depth = AOMMIN(gf_group->layer_depth[cpi->gf_frame_index], 6);
    566  const FRAME_TYPE frame_type = cm->current_frame.frame_type;
    567 
    568  // Set resolution_change flag: for single spatial layers only.
    569  const int resolution_change = !cpi->rc.rtc_external_ratectrl &&
    570                                cm->prev_frame &&
    571                                cpi->svc.number_spatial_layers == 1 &&
    572                                (cm->width != cm->prev_frame->width ||
    573                                 cm->height != cm->prev_frame->height);
    574 
    575  if (resolution_change && cpi->svc.temporal_layer_id == 0)
    576    cyclic_refresh_reset_resize(cpi);
    577  if (!cr->apply_cyclic_refresh) {
    578    // Don't disable and set seg_map to 0 if active_maps is enabled, unless
    579    // whole frame is set as inactive (since we only apply cyclic_refresh to
    580    // active blocks).
    581    if (!cpi->active_map.enabled || cpi->rc.percent_blocks_inactive == 100) {
    582      unsigned char *const seg_map = cpi->enc_seg.map;
    583      memset(seg_map, 0, cm->mi_params.mi_rows * cm->mi_params.mi_cols);
    584      av1_disable_segmentation(&cm->seg);
    585    }
    586    if (frame_is_intra_only(cm) || scene_change_detected ||
    587        cpi->ppi->rtc_ref.bias_recovery_frame) {
    588      cr->sb_index = 0;
    589      cr->last_sb_index = 0;
    590      cr->counter_encode_maxq_scene_change = 0;
    591      cr->actual_num_seg1_blocks = 0;
    592      cr->actual_num_seg2_blocks = 0;
    593    }
    594    return;
    595  } else {
    596    cr->counter_encode_maxq_scene_change++;
    597    const double q = av1_convert_qindex_to_q(cm->quant_params.base_qindex,
    598                                             cm->seq_params->bit_depth);
    599    // Set rate threshold to some multiple (set to 2 for now) of the target
    600    // rate (target is given by sb64_target_rate and scaled by 256).
    601    cr->thresh_rate_sb = ((int64_t)(rc->sb64_target_rate) << 8) << 2;
    602    // Distortion threshold, quadratic in Q, scale factor to be adjusted.
    603    // q will not exceed 457, so (q * q) is within 32bit; see:
    604    // av1_convert_qindex_to_q(), av1_ac_quant(), ac_qlookup*[].
    605    cr->thresh_dist_sb = ((int64_t)(q * q)) << 2;
    606    // For low-resoln or lower speeds, the rate/dist thresholds need to be
    607    // tuned/updated.
    608    if (cpi->oxcf.speed <= 7 || (cm->width * cm->height < 640 * 360)) {
    609      cr->thresh_dist_sb = 0;
    610      cr->thresh_rate_sb = INT64_MAX;
    611    }
    612    // Set up segmentation.
    613    av1_enable_segmentation(&cm->seg);
    614    if (!cpi->active_map.enabled) {
    615      // Clear down the segment map, only if active_maps is not enabled.
    616      av1_clearall_segfeatures(seg);
    617    }
    618 
    619    // Note: setting temporal_update has no effect, as the seg-map coding method
    620    // (temporal or spatial) is determined in
    621    // av1_choose_segmap_coding_method(),
    622    // based on the coding cost of each method. For error_resilient mode on the
    623    // last_frame_seg_map is set to 0, so if temporal coding is used, it is
    624    // relative to 0 previous map.
    625    // seg->temporal_update = 0;
    626 
    627    // Segment BASE "Q" feature is disabled so it defaults to the baseline Q.
    628    av1_disable_segfeature(seg, CR_SEGMENT_ID_BASE, SEG_LVL_ALT_Q);
    629    // Use segment BOOST1 for in-frame Q adjustment.
    630    av1_enable_segfeature(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q);
    631    // Use segment BOOST2 for more aggressive in-frame Q adjustment.
    632    av1_enable_segfeature(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q);
    633 
    634    // Set the q delta for segment BOOST1.
    635    const CommonQuantParams *const quant_params = &cm->quant_params;
    636    int qindex_delta =
    637        compute_deltaq(cpi, quant_params->base_qindex, cr->rate_ratio_qdelta);
    638    cr->qindex_delta[1] = qindex_delta;
    639 
    640    // Compute rd-mult for segment BOOST1.
    641    const int qindex2 = clamp(
    642        quant_params->base_qindex + quant_params->y_dc_delta_q + qindex_delta,
    643        0, MAXQ);
    644    cr->rdmult = av1_compute_rd_mult(
    645        qindex2, cm->seq_params->bit_depth,
    646        cpi->ppi->gf_group.update_type[cpi->gf_frame_index], layer_depth,
    647        boost_index, frame_type, cpi->oxcf.q_cfg.use_fixed_qp_offsets,
    648        is_stat_consumption_stage(cpi), cpi->oxcf.tune_cfg.tuning);
    649 
    650    av1_set_segdata(seg, CR_SEGMENT_ID_BOOST1, SEG_LVL_ALT_Q, qindex_delta);
    651 
    652    // Set a more aggressive (higher) q delta for segment BOOST2.
    653    qindex_delta = compute_deltaq(
    654        cpi, quant_params->base_qindex,
    655        AOMMIN(CR_MAX_RATE_TARGET_RATIO,
    656               0.1 * cr->rate_boost_fac * cr->rate_ratio_qdelta));
    657    cr->qindex_delta[2] = qindex_delta;
    658    av1_set_segdata(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q, qindex_delta);
    659 
    660    // Update the segmentation and refresh map.
    661    cyclic_refresh_update_map(cpi);
    662  }
    663 }
    664 
    665 int av1_cyclic_refresh_get_rdmult(const CYCLIC_REFRESH *cr) {
    666  return cr->rdmult;
    667 }
    668 
    669 int av1_cyclic_refresh_disable_lf_cdef(AV1_COMP *const cpi) {
    670  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
    671  const int qindex = cpi->common.quant_params.base_qindex;
    672  if (cpi->active_map.enabled &&
    673      cpi->rc.percent_blocks_inactive >
    674          cpi->sf.rt_sf.thresh_active_maps_skip_lf_cdef)
    675    return 1;
    676  if (cpi->rc.frames_since_key > 30 && cr->percent_refresh > 0 &&
    677      cr->counter_encode_maxq_scene_change > 300 / cr->percent_refresh &&
    678      cpi->rc.frame_source_sad < 1000 &&
    679      qindex < 7 * (cpi->rc.worst_quality >> 3))
    680    return 1;
    681  // More aggressive skip.
    682  else if (cpi->sf.rt_sf.skip_lf_screen > 1 && !cpi->rc.high_source_sad &&
    683           cpi->rc.frame_source_sad < 50000 && qindex < cpi->rc.worst_quality)
    684    return 1;
    685  return 0;
    686 }