Coverage Report

Created: 2022-08-24 06:17

/src/aom/av1/encoder/picklpf.c
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/*
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 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
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 *
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 * This source code is subject to the terms of the BSD 2 Clause License and
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 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
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 * was not distributed with this source code in the LICENSE file, you can
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 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
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 * Media Patent License 1.0 was not distributed with this source code in the
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 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
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 */
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#include <assert.h>
13
#include <limits.h>
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15
#include "config/aom_scale_rtcd.h"
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#include "aom_dsp/aom_dsp_common.h"
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#include "aom_dsp/psnr.h"
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#include "aom_mem/aom_mem.h"
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#include "aom_ports/mem.h"
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#include "av1/common/av1_common_int.h"
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#include "av1/common/av1_loopfilter.h"
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#include "av1/common/quant_common.h"
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#include "av1/encoder/av1_quantize.h"
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#include "av1/encoder/encoder.h"
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#include "av1/encoder/picklpf.h"
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static void yv12_copy_plane(const YV12_BUFFER_CONFIG *src_bc,
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0
                            YV12_BUFFER_CONFIG *dst_bc, int plane) {
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0
  switch (plane) {
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0
    case 0: aom_yv12_copy_y(src_bc, dst_bc); break;
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0
    case 1: aom_yv12_copy_u(src_bc, dst_bc); break;
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0
    case 2: aom_yv12_copy_v(src_bc, dst_bc); break;
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0
    default: assert(plane >= 0 && plane <= 2); break;
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0
  }
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0
}
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0
int av1_get_max_filter_level(const AV1_COMP *cpi) {
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0
  if (is_stat_consumption_stage_twopass(cpi)) {
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0
    return cpi->ppi->twopass.section_intra_rating > 8 ? MAX_LOOP_FILTER * 3 / 4
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0
                                                      : MAX_LOOP_FILTER;
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0
  } else {
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0
    return MAX_LOOP_FILTER;
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0
  }
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0
}
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static int64_t try_filter_frame(const YV12_BUFFER_CONFIG *sd,
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                                AV1_COMP *const cpi, int filt_level,
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0
                                int partial_frame, int plane, int dir) {
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0
  MultiThreadInfo *const mt_info = &cpi->mt_info;
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0
  int num_workers = mt_info->num_mod_workers[MOD_LPF];
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0
  AV1_COMMON *const cm = &cpi->common;
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0
  int64_t filt_err;
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0
  assert(plane >= 0 && plane <= 2);
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0
  int filter_level[2] = { filt_level, filt_level };
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  if (plane == 0 && dir == 0) filter_level[1] = cm->lf.filter_level[1];
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0
  if (plane == 0 && dir == 1) filter_level[0] = cm->lf.filter_level[0];
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  // set base filters for use of av1_get_filter_level when in DELTA_LF mode
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0
  switch (plane) {
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0
    case 0:
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0
      cm->lf.filter_level[0] = filter_level[0];
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0
      cm->lf.filter_level[1] = filter_level[1];
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0
      break;
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0
    case 1: cm->lf.filter_level_u = filter_level[0]; break;
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0
    case 2: cm->lf.filter_level_v = filter_level[0]; break;
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0
  }
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0
  av1_loop_filter_frame_mt(&cm->cur_frame->buf, cm, &cpi->td.mb.e_mbd, plane,
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                           plane + 1, partial_frame, mt_info->workers,
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                           num_workers, &mt_info->lf_row_sync, 0);
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0
  filt_err = aom_get_sse_plane(sd, &cm->cur_frame->buf, plane,
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0
                               cm->seq_params->use_highbitdepth);
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  // Re-instate the unfiltered frame
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0
  yv12_copy_plane(&cpi->last_frame_uf, &cm->cur_frame->buf, plane);
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0
  return filt_err;
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0
}
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static int search_filter_level(const YV12_BUFFER_CONFIG *sd, AV1_COMP *cpi,
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                               int partial_frame,
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                               const int *last_frame_filter_level, int plane,
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0
                               int dir) {
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0
  const AV1_COMMON *const cm = &cpi->common;
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  const int min_filter_level = 0;
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0
  const int max_filter_level = av1_get_max_filter_level(cpi);
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  int filt_direction = 0;
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  int64_t best_err;
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0
  int filt_best;
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  // Start the search at the previous frame filter level unless it is now out of
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  // range.
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  int lvl;
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0
  switch (plane) {
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0
    case 0:
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0
      switch (dir) {
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0
        case 2:
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0
          lvl = (last_frame_filter_level[0] + last_frame_filter_level[1] + 1) >>
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                1;
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0
          break;
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0
        case 0:
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0
        case 1: lvl = last_frame_filter_level[dir]; break;
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        default: assert(dir >= 0 && dir <= 2); return 0;
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0
      }
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0
      break;
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0
    case 1: lvl = last_frame_filter_level[2]; break;
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0
    case 2: lvl = last_frame_filter_level[3]; break;
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    default: assert(plane >= 0 && plane <= 2); return 0;
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0
  }
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0
  int filt_mid = clamp(lvl, min_filter_level, max_filter_level);
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0
  int filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
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  // Sum squared error at each filter level
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0
  int64_t ss_err[MAX_LOOP_FILTER + 1];
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0
  const int use_coarse_search = cpi->sf.lpf_sf.use_coarse_filter_level_search;
121
0
  assert(use_coarse_search <= 1);
122
0
  static const int min_filter_step_lookup[2] = { 0, 2 };
123
  // min_filter_step_thesh determines the stopping criteria for the search.
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  // The search is terminated when filter_step equals min_filter_step_thesh.
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0
  const int min_filter_step_thesh = min_filter_step_lookup[use_coarse_search];
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127
  // Set each entry to -1
128
0
  memset(ss_err, 0xFF, sizeof(ss_err));
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0
  yv12_copy_plane(&cm->cur_frame->buf, &cpi->last_frame_uf, plane);
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0
  best_err = try_filter_frame(sd, cpi, filt_mid, partial_frame, plane, dir);
131
0
  filt_best = filt_mid;
132
0
  ss_err[filt_mid] = best_err;
133
134
0
  while (filter_step > min_filter_step_thesh) {
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0
    const int filt_high = AOMMIN(filt_mid + filter_step, max_filter_level);
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0
    const int filt_low = AOMMAX(filt_mid - filter_step, min_filter_level);
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    // Bias against raising loop filter in favor of lowering it.
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0
    int64_t bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
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141
0
    if ((is_stat_consumption_stage_twopass(cpi)) &&
142
0
        (cpi->ppi->twopass.section_intra_rating < 20))
143
0
      bias = (bias * cpi->ppi->twopass.section_intra_rating) / 20;
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145
    // yx, bias less for large block size
146
0
    if (cm->features.tx_mode != ONLY_4X4) bias >>= 1;
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148
0
    if (filt_direction <= 0 && filt_low != filt_mid) {
149
      // Get Low filter error score
150
0
      if (ss_err[filt_low] < 0) {
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0
        ss_err[filt_low] =
152
0
            try_filter_frame(sd, cpi, filt_low, partial_frame, plane, dir);
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0
      }
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      // If value is close to the best so far then bias towards a lower loop
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      // filter value.
156
0
      if (ss_err[filt_low] < (best_err + bias)) {
157
        // Was it actually better than the previous best?
158
0
        if (ss_err[filt_low] < best_err) {
159
0
          best_err = ss_err[filt_low];
160
0
        }
161
0
        filt_best = filt_low;
162
0
      }
163
0
    }
164
165
    // Now look at filt_high
166
0
    if (filt_direction >= 0 && filt_high != filt_mid) {
167
0
      if (ss_err[filt_high] < 0) {
168
0
        ss_err[filt_high] =
169
0
            try_filter_frame(sd, cpi, filt_high, partial_frame, plane, dir);
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0
      }
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      // If value is significantly better than previous best, bias added against
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      // raising filter value
173
0
      if (ss_err[filt_high] < (best_err - bias)) {
174
0
        best_err = ss_err[filt_high];
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0
        filt_best = filt_high;
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0
      }
177
0
    }
178
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    // Half the step distance if the best filter value was the same as last time
180
0
    if (filt_best == filt_mid) {
181
0
      filter_step /= 2;
182
0
      filt_direction = 0;
183
0
    } else {
184
0
      filt_direction = (filt_best < filt_mid) ? -1 : 1;
185
0
      filt_mid = filt_best;
186
0
    }
187
0
  }
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189
0
  return filt_best;
190
0
}
191
192
void av1_pick_filter_level(const YV12_BUFFER_CONFIG *sd, AV1_COMP *cpi,
193
0
                           LPF_PICK_METHOD method) {
194
0
  AV1_COMMON *const cm = &cpi->common;
195
0
  const SequenceHeader *const seq_params = cm->seq_params;
196
0
  const int num_planes = av1_num_planes(cm);
197
0
  struct loopfilter *const lf = &cm->lf;
198
0
  (void)sd;
199
200
0
  lf->sharpness_level = 0;
201
0
  cpi->td.mb.rdmult = cpi->rd.RDMULT;
202
203
0
  if (cpi->oxcf.algo_cfg.loopfilter_control == LOOPFILTER_NONE ||
204
0
      (cpi->oxcf.algo_cfg.loopfilter_control == LOOPFILTER_REFERENCE &&
205
0
       cpi->svc.non_reference_frame)) {
206
0
    lf->filter_level[0] = 0;
207
0
    lf->filter_level[1] = 0;
208
0
    return;
209
0
  }
210
211
0
  if (method == LPF_PICK_MINIMAL_LPF) {
212
0
    lf->filter_level[0] = 0;
213
0
    lf->filter_level[1] = 0;
214
0
  } else if (method >= LPF_PICK_FROM_Q) {
215
0
    const int min_filter_level = 0;
216
0
    const int max_filter_level = av1_get_max_filter_level(cpi);
217
0
    const int q = av1_ac_quant_QTX(cm->quant_params.base_qindex, 0,
218
0
                                   seq_params->bit_depth);
219
    // based on tests result for rtc test set
220
    // 0.04590 boosted or 0.02295 non-booseted in 18-bit fixed point
221
0
    const int strength_boost_q_treshold = 0;
222
0
    int inter_frame_multiplier =
223
0
        (q > strength_boost_q_treshold ||
224
0
         (cpi->sf.rt_sf.use_nonrd_pick_mode &&
225
0
          cpi->common.width * cpi->common.height > 352 * 288))
226
0
            ? 12034
227
0
            : 6017;
228
    // These values were determined by linear fitting the result of the
229
    // searched level for 8 bit depth:
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    // Keyframes: filt_guess = q * 0.06699 - 1.60817
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    // Other frames: filt_guess = q * inter_frame_multiplier + 2.48225
232
    //
233
    // And high bit depth separately:
234
    // filt_guess = q * 0.316206 + 3.87252
235
0
    int filt_guess;
236
0
    switch (seq_params->bit_depth) {
237
0
      case AOM_BITS_8:
238
0
        filt_guess =
239
0
            (cm->current_frame.frame_type == KEY_FRAME)
240
0
                ? ROUND_POWER_OF_TWO(q * 17563 - 421574, 18)
241
0
                : ROUND_POWER_OF_TWO(q * inter_frame_multiplier + 650707, 18);
242
0
        break;
243
0
      case AOM_BITS_10:
244
0
        filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 4060632, 20);
245
0
        break;
246
0
      case AOM_BITS_12:
247
0
        filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 16242526, 22);
248
0
        break;
249
0
      default:
250
0
        assert(0 &&
251
0
               "bit_depth should be AOM_BITS_8, AOM_BITS_10 "
252
0
               "or AOM_BITS_12");
253
0
        return;
254
0
    }
255
0
    if (seq_params->bit_depth != AOM_BITS_8 &&
256
0
        cm->current_frame.frame_type == KEY_FRAME)
257
0
      filt_guess -= 4;
258
    // TODO(chengchen): retrain the model for Y, U, V filter levels
259
0
    lf->filter_level[0] = clamp(filt_guess, min_filter_level, max_filter_level);
260
0
    lf->filter_level[1] = clamp(filt_guess, min_filter_level, max_filter_level);
261
0
    lf->filter_level_u = clamp(filt_guess, min_filter_level, max_filter_level);
262
0
    lf->filter_level_v = clamp(filt_guess, min_filter_level, max_filter_level);
263
0
    if (cpi->oxcf.algo_cfg.loopfilter_control == LOOPFILTER_SELECTIVELY &&
264
0
        !frame_is_intra_only(cm)) {
265
0
      const int num4x4 = (cm->width >> 2) * (cm->height >> 2);
266
0
      const int newmv_thresh = 7;
267
0
      const int distance_since_key_thresh = 5;
268
0
      if ((cpi->td.rd_counts.newmv_or_intra_blocks * 100 / num4x4) <
269
0
              newmv_thresh &&
270
0
          cpi->rc.frames_since_key > distance_since_key_thresh) {
271
0
        lf->filter_level[0] = 0;
272
0
        lf->filter_level[1] = 0;
273
0
      }
274
0
    }
275
0
  } else {
276
0
    int last_frame_filter_level[4] = { 0 };
277
0
    if (!frame_is_intra_only(cm)) {
278
#if CONFIG_FRAME_PARALLEL_ENCODE
279
      last_frame_filter_level[0] = cpi->ppi->filter_level[0];
280
      last_frame_filter_level[1] = cpi->ppi->filter_level[1];
281
      last_frame_filter_level[2] = cpi->ppi->filter_level_u;
282
      last_frame_filter_level[3] = cpi->ppi->filter_level_v;
283
#else
284
0
      last_frame_filter_level[0] = lf->filter_level[0];
285
0
      last_frame_filter_level[1] = lf->filter_level[1];
286
0
      last_frame_filter_level[2] = lf->filter_level_u;
287
0
      last_frame_filter_level[3] = lf->filter_level_v;
288
0
#endif
289
0
    }
290
    // The frame buffer last_frame_uf is used to store the non-loop filtered
291
    // reconstructed frame in search_filter_level().
292
0
    if (aom_realloc_frame_buffer(
293
0
            &cpi->last_frame_uf, cm->width, cm->height,
294
0
            seq_params->subsampling_x, seq_params->subsampling_y,
295
0
            seq_params->use_highbitdepth, cpi->oxcf.border_in_pixels,
296
0
            cm->features.byte_alignment, NULL, NULL, NULL, 0))
297
0
      aom_internal_error(cm->error, AOM_CODEC_MEM_ERROR,
298
0
                         "Failed to allocate last frame buffer");
299
300
0
    lf->filter_level[0] = lf->filter_level[1] =
301
0
        search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE,
302
0
                            last_frame_filter_level, 0, 2);
303
0
    if (method != LPF_PICK_FROM_FULL_IMAGE_NON_DUAL) {
304
0
      lf->filter_level[0] =
305
0
          search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE,
306
0
                              last_frame_filter_level, 0, 0);
307
0
      lf->filter_level[1] =
308
0
          search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE,
309
0
                              last_frame_filter_level, 0, 1);
310
0
    }
311
312
0
    if (num_planes > 1) {
313
0
      lf->filter_level_u =
314
0
          search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE,
315
0
                              last_frame_filter_level, 1, 0);
316
0
      lf->filter_level_v =
317
0
          search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE,
318
0
                              last_frame_filter_level, 2, 0);
319
0
    }
320
0
  }
321
0
}