path: root/vp9/encoder/vp9_denoiser.c

/*
 *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <assert.h>
#include <limits.h>
#include <math.h>

#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_scale/yv12config.h"
#include "vpx/vpx_integer.h"
#include "vp9/common/vp9_reconinter.h"
#include "vp9/encoder/vp9_context_tree.h"
#include "vp9/encoder/vp9_denoiser.h"
#include "vp9/encoder/vp9_encoder.h"

#ifdef OUTPUT_YUV_DENOISED
static void make_grayscale(YV12_BUFFER_CONFIG *yuv);
#endif

static int absdiff_thresh(BLOCK_SIZE bs, int increase_denoising) {
  (void)bs;
  return 3 + (increase_denoising ? 1 : 0);
}

static int delta_thresh(BLOCK_SIZE bs, int increase_denoising) {
  (void)bs;
  (void)increase_denoising;
  return 4;
}

static int noise_motion_thresh(BLOCK_SIZE bs, int increase_denoising) {
  (void)bs;
  (void)increase_denoising;
  return 625;
}

static unsigned int sse_thresh(BLOCK_SIZE bs, int increase_denoising) {
  return (1 << num_pels_log2_lookup[bs]) * (increase_denoising ? 80 : 40);
}

static int sse_diff_thresh(BLOCK_SIZE bs, int increase_denoising,
                           int motion_magnitude) {
  if (motion_magnitude > noise_motion_thresh(bs, increase_denoising)) {
    if (increase_denoising)
      return (1 << num_pels_log2_lookup[bs]) << 2;
    else
      return 0;
  } else {
    return (1 << num_pels_log2_lookup[bs]) << 4;
  }
}

static int total_adj_weak_thresh(BLOCK_SIZE bs, int increase_denoising) {
  return (1 << num_pels_log2_lookup[bs]) * (increase_denoising ? 3 : 2);
}

// TODO(jackychen): If increase_denoising is enabled in the future,
// we might need to update the code for calculating 'total_adj' in
// case the C code is not bit-exact with corresponding sse2 code.
int vp9_denoiser_filter_c(const uint8_t *sig, int sig_stride,
                          const uint8_t *mc_avg, int mc_avg_stride,
                          uint8_t *avg, int avg_stride, int increase_denoising,
                          BLOCK_SIZE bs, int motion_magnitude) {
  int r, c;
  const uint8_t *sig_start = sig;
  const uint8_t *mc_avg_start = mc_avg;
  uint8_t *avg_start = avg;
  int diff, adj, absdiff, delta;
  int adj_val[] = { 3, 4, 6 };
  int total_adj = 0;
  int shift_inc = 1;

  // If motion_magnitude is small, making the denoiser more aggressive by
  // increasing the adjustment for each level. Add another increment for
  // blocks that are labeled for increase denoising.
  if (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) {
    if (increase_denoising) {
      shift_inc = 2;
    }
    adj_val[0] += shift_inc;
    adj_val[1] += shift_inc;
    adj_val[2] += shift_inc;
  }

  // First attempt to apply a strong temporal denoising filter.
  for (r = 0; r < (4 << b_height_log2_lookup[bs]); ++r) {
    for (c = 0; c < (4 << b_width_log2_lookup[bs]); ++c) {
      diff = mc_avg[c] - sig[c];
      absdiff = abs(diff);

      if (absdiff <= absdiff_thresh(bs, increase_denoising)) {
        avg[c] = mc_avg[c];
        total_adj += diff;
      } else {
        switch (absdiff) {
          case 4:
          case 5:
          case 6:
          case 7: adj = adj_val[0]; break;
          case 8:
          case 9:
          case 10:
          case 11:
          case 12:
          case 13:
          case 14:
          case 15: adj = adj_val[1]; break;
          default: adj = adj_val[2];
        }
        if (diff > 0) {
          avg[c] = VPXMIN(UINT8_MAX, sig[c] + adj);
          total_adj += adj;
        } else {
          avg[c] = VPXMAX(0, sig[c] - adj);
          total_adj -= adj;
        }
      }
    }
    sig += sig_stride;
    avg += avg_stride;
    mc_avg += mc_avg_stride;
  }

  // If the strong filter did not modify the signal too much, we're all set.
  if (abs(total_adj) <= total_adj_strong_thresh(bs, increase_denoising)) {
    return FILTER_BLOCK;
  }

  // Otherwise, we try to dampen the filter if the delta is not too high.
  delta = ((abs(total_adj) - total_adj_strong_thresh(bs, increase_denoising)) >>
           num_pels_log2_lookup[bs]) +
          1;

  if (delta >= delta_thresh(bs, increase_denoising)) {
    return COPY_BLOCK;
  }

  mc_avg = mc_avg_start;
  avg = avg_start;
  sig = sig_start;
  for (r = 0; r < (4 << b_height_log2_lookup[bs]); ++r) {
    for (c = 0; c < (4 << b_width_log2_lookup[bs]); ++c) {
      diff = mc_avg[c] - sig[c];
      adj = abs(diff);
      if (adj > delta) {
        adj = delta;
      }
      if (diff > 0) {
        // Diff positive means we made positive adjustment above
        // (in first try/attempt), so now make negative adjustment to bring
        // denoised signal down.
        avg[c] = VPXMAX(0, avg[c] - adj);
        total_adj -= adj;
      } else {
        // Diff negative means we made negative adjustment above
        // (in first try/attempt), so now make positive adjustment to bring
        // denoised signal up.
        avg[c] = VPXMIN(UINT8_MAX, avg[c] + adj);
        total_adj += adj;
      }
    }
    sig += sig_stride;
    avg += avg_stride;
    mc_avg += mc_avg_stride;
  }

  // We can use the filter if it has been sufficiently dampened
  if (abs(total_adj) <= total_adj_weak_thresh(bs, increase_denoising)) {
    return FILTER_BLOCK;
  }
  return COPY_BLOCK;
}

static uint8_t *block_start(uint8_t *framebuf, int stride, int mi_row,
                            int mi_col) {
  return framebuf + (stride * mi_row << 3) + (mi_col << 3);
}

static VP9_DENOISER_DECISION perform_motion_compensation(
    VP9_COMMON *const cm, VP9_DENOISER *denoiser, MACROBLOCK *mb, BLOCK_SIZE bs,
    int increase_denoising, int mi_row, int mi_col, PICK_MODE_CONTEXT *ctx,
    int motion_magnitude, int is_skin, int *zeromv_filter, int consec_zeromv,
    int num_spatial_layers, int width, int lst_fb_idx, int gld_fb_idx,
    int use_svc, int spatial_layer, int use_gf_temporal_ref) {
  const int sse_diff = (ctx->newmv_sse == UINT_MAX)
                           ? 0
                           : ((int)ctx->zeromv_sse - (int)ctx->newmv_sse);
  int frame;
  int denoise_layer_idx = 0;
  MACROBLOCKD *filter_mbd = &mb->e_mbd;
  MODE_INFO *mi = filter_mbd->mi[0];
  MODE_INFO saved_mi;
  int i;
  struct buf_2d saved_dst[MAX_MB_PLANE];
  struct buf_2d saved_pre[MAX_MB_PLANE];
  RefBuffer *saved_block_refs[2];
  MV_REFERENCE_FRAME saved_frame;

  frame = ctx->best_reference_frame;

  saved_mi = *mi;

  if (is_skin && (motion_magnitude > 0 || consec_zeromv < 4)) return COPY_BLOCK;

  // Avoid denoising small blocks. When noise > kDenLow or frame width > 480,
  // denoise 16x16 blocks.
  if (bs == BLOCK_8X8 || bs == BLOCK_8X16 || bs == BLOCK_16X8 ||
      (bs == BLOCK_16X16 && width > 480 &&
       denoiser->denoising_level <= kDenLow))
    return COPY_BLOCK;

  // If the best reference frame uses inter-prediction and there is enough of a
  // difference in sum-squared-error, use it.
  if (frame != INTRA_FRAME && frame != ALTREF_FRAME &&
      (frame != GOLDEN_FRAME || num_spatial_layers == 1 ||
       use_gf_temporal_ref) &&
      sse_diff > sse_diff_thresh(bs, increase_denoising, motion_magnitude)) {
    mi->ref_frame[0] = ctx->best_reference_frame;
    mi->mode = ctx->best_sse_inter_mode;
    mi->mv[0] = ctx->best_sse_mv;
  } else {
    // Otherwise, use the zero reference frame.
    frame = ctx->best_zeromv_reference_frame;
    ctx->newmv_sse = ctx->zeromv_sse;
    // Bias to last reference.
    if ((num_spatial_layers > 1 && !use_gf_temporal_ref) ||
        frame == ALTREF_FRAME ||
        (frame != LAST_FRAME &&
         ((ctx->zeromv_lastref_sse<(5 * ctx->zeromv_sse)>> 2) ||
          denoiser->denoising_level >= kDenHigh))) {
      frame = LAST_FRAME;
      ctx->newmv_sse = ctx->zeromv_lastref_sse;
    }
    mi->ref_frame[0] = frame;
    mi->mode = ZEROMV;
    mi->mv[0].as_int = 0;
    ctx->best_sse_inter_mode = ZEROMV;
    ctx->best_sse_mv.as_int = 0;
    *zeromv_filter = 1;
    if (denoiser->denoising_level > kDenMedium) {
      motion_magnitude = 0;
    }
  }

  saved_frame = frame;
  // When using SVC, we need to map REF_FRAME to the frame buffer index.
  if (use_svc) {
    if (frame == LAST_FRAME)
      frame = lst_fb_idx + 1;
    else if (frame == GOLDEN_FRAME)
      frame = gld_fb_idx + 1;
    // Shift for the second spatial layer.
    if (num_spatial_layers - spatial_layer == 2)
      frame = frame + denoiser->num_ref_frames;
    denoise_layer_idx = num_spatial_layers - spatial_layer - 1;
  }

  // Force copy (no denoise, copy source in denoised buffer) if
  // running_avg_y[frame] is NULL.
  if (denoiser->running_avg_y[frame].buffer_alloc == NULL) {
    // Restore everything to its original state
    *mi = saved_mi;
    return COPY_BLOCK;
  }

  if (ctx->newmv_sse > sse_thresh(bs, increase_denoising)) {
    // Restore everything to its original state
    *mi = saved_mi;
    return COPY_BLOCK;
  }
  if (motion_magnitude > (noise_motion_thresh(bs, increase_denoising) << 3)) {
    // Restore everything to its original state
    *mi = saved_mi;
    return COPY_BLOCK;
  }

  // We will restore these after motion compensation.
  for (i = 0; i < MAX_MB_PLANE; ++i) {
    saved_pre[i] = filter_mbd->plane[i].pre[0];
    saved_dst[i] = filter_mbd->plane[i].dst;
  }
  saved_block_refs[0] = filter_mbd->block_refs[0];

  // Set the pointers in the MACROBLOCKD to point to the buffers in the denoiser
  // struct.
  filter_mbd->plane[0].pre[0].buf =
      block_start(denoiser->running_avg_y[frame].y_buffer,
                  denoiser->running_avg_y[frame].y_stride, mi_row, mi_col);
  filter_mbd->plane[0].pre[0].stride = denoiser->running_avg_y[frame].y_stride;
  filter_mbd->plane[1].pre[0].buf =
      block_start(denoiser->running_avg_y[frame].u_buffer,
                  denoiser->running_avg_y[frame].uv_stride, mi_row, mi_col);
  filter_mbd->plane[1].pre[0].stride = denoiser->running_avg_y[frame].uv_stride;
  filter_mbd->plane[2].pre[0].buf =
      block_start(denoiser->running_avg_y[frame].v_buffer,
                  denoiser->running_avg_y[frame].uv_stride, mi_row, mi_col);
  filter_mbd->plane[2].pre[0].stride = denoiser->running_avg_y[frame].uv_stride;

  filter_mbd->plane[0].dst.buf = block_start(
      denoiser->mc_running_avg_y[denoise_layer_idx].y_buffer,
      denoiser->mc_running_avg_y[denoise_layer_idx].y_stride, mi_row, mi_col);
  filter_mbd->plane[0].dst.stride =
      denoiser->mc_running_avg_y[denoise_layer_idx].y_stride;
  filter_mbd->plane[1].dst.buf = block_start(
      denoiser->mc_running_avg_y[denoise_layer_idx].u_buffer,
      denoiser->mc_running_avg_y[denoise_layer_idx].uv_stride, mi_row, mi_col);
  filter_mbd->plane[1].dst.stride =
      denoiser->mc_running_avg_y[denoise_layer_idx].uv_stride;
  filter_mbd->plane[2].dst.buf = block_start(
      denoiser->mc_running_avg_y[denoise_layer_idx].v_buffer,
      denoiser->mc_running_avg_y[denoise_layer_idx].uv_stride, mi_row, mi_col);
  filter_mbd->plane[2].dst.stride =
      denoiser->mc_running_avg_y[denoise_layer_idx].uv_stride;

  set_ref_ptrs(cm, filter_mbd, saved_frame, NONE);
  vp9_build_inter_predictors_sby(filter_mbd, mi_row, mi_col, bs);

  // Restore everything to its original state
  *mi = saved_mi;
  filter_mbd->block_refs[0] = saved_block_refs[0];
  for (i = 0; i < MAX_MB_PLANE; ++i) {
    filter_mbd->plane[i].pre[0] = saved_pre[i];
    filter_mbd->plane[i].dst = saved_dst[i];
  }

  return FILTER_BLOCK;
}

void vp9_denoiser_denoise(VP9_COMP *cpi, MACROBLOCK *mb, int mi_row, int mi_col,
                          BLOCK_SIZE bs, PICK_MODE_CONTEXT *ctx,
                          VP9_DENOISER_DECISION *denoiser_decision,
                          int use_gf_temporal_ref) {
  int mv_col, mv_row;
  int motion_magnitude = 0;
  int zeromv_filter = 0;
  VP9_DENOISER *denoiser = &cpi->denoiser;
  VP9_DENOISER_DECISION decision = COPY_BLOCK;

  const int shift =
      cpi->svc.number_spatial_layers - cpi->svc.spatial_layer_id == 2
          ? denoiser->num_ref_frames
          : 0;
  YV12_BUFFER_CONFIG avg = denoiser->running_avg_y[INTRA_FRAME + shift];
  const int denoise_layer_index =
      cpi->svc.number_spatial_layers - cpi->svc.spatial_layer_id - 1;
  YV12_BUFFER_CONFIG mc_avg = denoiser->mc_running_avg_y[denoise_layer_index];
  uint8_t *avg_start = block_start(avg.y_buffer, avg.y_stride, mi_row, mi_col);

  uint8_t *mc_avg_start =
      block_start(mc_avg.y_buffer, mc_avg.y_stride, mi_row, mi_col);
  struct buf_2d src = mb->plane[0].src;
  int is_skin = 0;
  int increase_denoising = 0;
  int consec_zeromv = 0;
  mv_col = ctx->best_sse_mv.as_mv.col;
  mv_row = ctx->best_sse_mv.as_mv.row;
  motion_magnitude = mv_row * mv_row + mv_col * mv_col;

  if (cpi->use_skin_detection && bs <= BLOCK_32X32 &&
      denoiser->denoising_level < kDenHigh) {
    int motion_level = (motion_magnitude < 16) ? 0 : 1;
    // If motion for current block is small/zero, compute consec_zeromv for
    // skin detection (early exit in skin detection is done for large
    // consec_zeromv when current block has small/zero motion).
    consec_zeromv = 0;
    if (motion_level == 0) {
      VP9_COMMON *const cm = &cpi->common;
      int j, i;
      // Loop through the 8x8 sub-blocks.
      const int bw = num_8x8_blocks_wide_lookup[bs];
      const int bh = num_8x8_blocks_high_lookup[bs];
      const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
      const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
      const int block_index = mi_row * cm->mi_cols + mi_col;
      consec_zeromv = 100;
      for (i = 0; i < ymis; i++) {
        for (j = 0; j < xmis; j++) {
          int bl_index = block_index + i * cm->mi_cols + j;
          consec_zeromv = VPXMIN(cpi->consec_zero_mv[bl_index], consec_zeromv);
          // No need to keep checking 8x8 blocks if any of the sub-blocks
          // has small consec_zeromv (since threshold for no_skin based on
          // zero/small motion in skin detection is high, i.e, > 4).
          if (consec_zeromv < 4) {
            i = ymis;
            break;
          }
        }
      }
    }
    // TODO(marpan): Compute skin detection over sub-blocks.
    is_skin = vp9_compute_skin_block(
        mb->plane[0].src.buf, mb->plane[1].src.buf, mb->plane[2].src.buf,
        mb->plane[0].src.stride, mb->plane[1].src.stride, bs, consec_zeromv,
        motion_level);
  }
  if (!is_skin && denoiser->denoising_level == kDenHigh) increase_denoising = 1;

  if (denoiser->denoising_level >= kDenLow && !ctx->sb_skip_denoising)
    decision = perform_motion_compensation(
        &cpi->common, denoiser, mb, bs, increase_denoising, mi_row, mi_col, ctx,
        motion_magnitude, is_skin, &zeromv_filter, consec_zeromv,
        cpi->svc.number_spatial_layers, cpi->Source->y_width, cpi->lst_fb_idx,
        cpi->gld_fb_idx, cpi->use_svc, cpi->svc.spatial_layer_id,
        use_gf_temporal_ref);

  if (decision == FILTER_BLOCK) {
    decision = vp9_denoiser_filter(src.buf, src.stride, mc_avg_start,
                                   mc_avg.y_stride, avg_start, avg.y_stride,
                                   increase_denoising, bs, motion_magnitude);
  }

  if (decision == FILTER_BLOCK) {
    vpx_convolve_copy(avg_start, avg.y_stride, src.buf, src.stride, NULL, 0, 0,
                      0, 0, num_4x4_blocks_wide_lookup[bs] << 2,
                      num_4x4_blocks_high_lookup[bs] << 2);
  } else {  // COPY_BLOCK
    vpx_convolve_copy(src.buf, src.stride, avg_start, avg.y_stride, NULL, 0, 0,
                      0, 0, num_4x4_blocks_wide_lookup[bs] << 2,
                      num_4x4_blocks_high_lookup[bs] << 2);
  }
  *denoiser_decision = decision;
  if (decision == FILTER_BLOCK && zeromv_filter == 1)
    *denoiser_decision = FILTER_ZEROMV_BLOCK;
}

static void copy_frame(YV12_BUFFER_CONFIG *const dest,
                       const YV12_BUFFER_CONFIG *const src) {
  int r;
  const uint8_t *srcbuf = src->y_buffer;
  uint8_t *destbuf = dest->y_buffer;

  assert(dest->y_width == src->y_width);
  assert(dest->y_height == src->y_height);

  for (r = 0; r < dest->y_height; ++r) {
    memcpy(destbuf, srcbuf, dest->y_width);
    destbuf += dest->y_stride;
    srcbuf += src->y_stride;
  }
}

static void swap_frame_buffer(YV12_BUFFER_CONFIG *const dest,
                              YV12_BUFFER_CONFIG *const src) {
  uint8_t *tmp_buf = dest->y_buffer;
  assert(dest->y_width == src->y_width);
  assert(dest->y_height == src->y_height);
  dest->y_buffer = src->y_buffer;
  src->y_buffer = tmp_buf;
}

void vp9_denoiser_update_frame_info(
    VP9_DENOISER *denoiser, YV12_BUFFER_CONFIG src, struct SVC *svc,
    FRAME_TYPE frame_type, int refresh_alt_ref_frame, int refresh_golden_frame,
    int refresh_last_frame, int alt_fb_idx, int gld_fb_idx, int lst_fb_idx,
    int resized, int svc_refresh_denoiser_buffers, int second_spatial_layer) {
  const int shift = second_spatial_layer ? denoiser->num_ref_frames : 0;
  // Copy source into denoised reference buffers on KEY_FRAME or
  // if the just encoded frame was resized. For SVC, copy source if the base
  // spatial layer was key frame.
  if (frame_type == KEY_FRAME || resized != 0 || denoiser->reset ||
      svc_refresh_denoiser_buffers) {
    int i;
    // Start at 1 so as not to overwrite the INTRA_FRAME
    for (i = 1; i < denoiser->num_ref_frames; ++i) {
      if (denoiser->running_avg_y[i + shift].buffer_alloc != NULL)
        copy_frame(&denoiser->running_avg_y[i + shift], &src);
    }
    denoiser->reset = 0;
    return;
  }

  if (svc->temporal_layering_mode == VP9E_TEMPORAL_LAYERING_MODE_BYPASS &&
      svc->use_set_ref_frame_config) {
    int i;
    for (i = 0; i < REF_FRAMES; i++) {
      if (svc->update_buffer_slot[svc->spatial_layer_id] & (1 << i))
        copy_frame(&denoiser->running_avg_y[i + 1 + shift],
                   &denoiser->running_avg_y[INTRA_FRAME + shift]);
    }
  } else {
    // If more than one refresh occurs, must copy frame buffer.
    if ((refresh_alt_ref_frame + refresh_golden_frame + refresh_last_frame) >
        1) {
      if (refresh_alt_ref_frame) {
        copy_frame(&denoiser->running_avg_y[alt_fb_idx + 1 + shift],
                   &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
      if (refresh_golden_frame) {
        copy_frame(&denoiser->running_avg_y[gld_fb_idx + 1 + shift],
                   &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
      if (refresh_last_frame) {
        copy_frame(&denoiser->running_avg_y[lst_fb_idx + 1 + shift],
                   &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
    } else {
      if (refresh_alt_ref_frame) {
        swap_frame_buffer(&denoiser->running_avg_y[alt_fb_idx + 1 + shift],
                          &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
      if (refresh_golden_frame) {
        swap_frame_buffer(&denoiser->running_avg_y[gld_fb_idx + 1 + shift],
                          &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
      if (refresh_last_frame) {
        swap_frame_buffer(&denoiser->running_avg_y[lst_fb_idx + 1 + shift],
                          &denoiser->running_avg_y[INTRA_FRAME + shift]);
      }
    }
  }
}

void vp9_denoiser_reset_frame_stats(PICK_MODE_CONTEXT *ctx) {
  ctx->zeromv_sse = UINT_MAX;
  ctx->newmv_sse = UINT_MAX;
  ctx->zeromv_lastref_sse = UINT_MAX;
  ctx->best_sse_mv.as_int = 0;
}

void vp9_denoiser_update_frame_stats(MODE_INFO *mi, unsigned int sse,
                                     PREDICTION_MODE mode,
                                     PICK_MODE_CONTEXT *ctx) {
  if (mi->mv[0].as_int == 0 && sse < ctx->zeromv_sse) {
    ctx->zeromv_sse = sse;
    ctx->best_zeromv_reference_frame = mi->ref_frame[0];
    if (mi->ref_frame[0] == LAST_FRAME) ctx->zeromv_lastref_sse = sse;
  }

  if (mi->mv[0].as_int != 0 && sse < ctx->newmv_sse) {
    ctx->newmv_sse = sse;
    ctx->best_sse_inter_mode = mode;
    ctx->best_sse_mv = mi->mv[0];
    ctx->best_reference_frame = mi->ref_frame[0];
  }
}

static int vp9_denoiser_realloc_svc_helper(VP9_COMMON *cm,
                                           VP9_DENOISER *denoiser, int fb_idx) {
  int fail = 0;
  if (denoiser->running_avg_y[fb_idx].buffer_alloc == NULL) {
    fail =
        vpx_alloc_frame_buffer(&denoiser->running_avg_y[fb_idx], cm->width,
                               cm->height, cm->subsampling_x, cm->subsampling_y,
#if CONFIG_VP9_HIGHBITDEPTH
                               cm->use_highbitdepth,
#endif
                               VP9_ENC_BORDER_IN_PIXELS, 0);
    if (fail) {
      vp9_denoiser_free(denoiser);
      return 1;
    }
  }
  return 0;
}

int vp9_denoiser_realloc_svc(VP9_COMMON *cm, VP9_DENOISER *denoiser,
                             struct SVC *svc, int svc_buf_shift,
                             int refresh_alt, int refresh_gld, int refresh_lst,
                             int alt_fb_idx, int gld_fb_idx, int lst_fb_idx) {
  int fail = 0;
  if (svc->temporal_layering_mode == VP9E_TEMPORAL_LAYERING_MODE_BYPASS &&
      svc->use_set_ref_frame_config) {
    int i;
    for (i = 0; i < REF_FRAMES; i++) {
      if (cm->frame_type == KEY_FRAME ||
          svc->update_buffer_slot[svc->spatial_layer_id] & (1 << i)) {
        fail = vp9_denoiser_realloc_svc_helper(cm, denoiser,
                                               i + 1 + svc_buf_shift);
      }
    }
  } else {
    if (refresh_alt) {
      // Increase the frame buffer index by 1 to map it to the buffer index in
      // the denoiser.
      fail = vp9_denoiser_realloc_svc_helper(cm, denoiser,
                                             alt_fb_idx + 1 + svc_buf_shift);
      if (fail) return 1;
    }
    if (refresh_gld) {
      fail = vp9_denoiser_realloc_svc_helper(cm, denoiser,
                                             gld_fb_idx + 1 + svc_buf_shift);
      if (fail) return 1;
    }
    if (refresh_lst) {
      fail = vp9_denoiser_realloc_svc_helper(cm, denoiser,
                                             lst_fb_idx + 1 + svc_buf_shift);
      if (fail) return 1;
    }
  }
  return 0;
}

int vp9_denoiser_alloc(VP9_COMMON *cm, struct SVC *svc, VP9_DENOISER *denoiser,
                       int use_svc, int noise_sen, int width, int height,
                       int ssx, int ssy,
#if CONFIG_VP9_HIGHBITDEPTH
                       int use_highbitdepth,
#endif
                       int border) {
  int i, layer, fail, init_num_ref_frames;
  const int legacy_byte_alignment = 0;
  int num_layers = 1;
  int scaled_width = width;
  int scaled_height = height;
  if (use_svc) {
    LAYER_CONTEXT *lc = &svc->layer_context[svc->spatial_layer_id *
                                                svc->number_temporal_layers +
                                            svc->temporal_layer_id];
    get_layer_resolution(width, height, lc->scaling_factor_num,
                         lc->scaling_factor_den, &scaled_width, &scaled_height);
    // For SVC: only denoise at most 2 spatial (highest) layers.
    if (noise_sen >= 2)
      // Denoise from one spatial layer below the top.
      svc->first_layer_denoise = VPXMAX(svc->number_spatial_layers - 2, 0);
    else
      // Only denoise the top spatial layer.
      svc->first_layer_denoise = VPXMAX(svc->number_spatial_layers - 1, 0);
    num_layers = svc->number_spatial_layers - svc->first_layer_denoise;
  }
  assert(denoiser != NULL);
  denoiser->num_ref_frames = use_svc ? SVC_REF_FRAMES : NONSVC_REF_FRAMES;
  init_num_ref_frames = use_svc ? MAX_REF_FRAMES : NONSVC_REF_FRAMES;
  denoiser->num_layers = num_layers;
  CHECK_MEM_ERROR(cm, denoiser->running_avg_y,
                  vpx_calloc(denoiser->num_ref_frames * num_layers,
                             sizeof(denoiser->running_avg_y[0])));
  CHECK_MEM_ERROR(
      cm, denoiser->mc_running_avg_y,
      vpx_calloc(num_layers, sizeof(denoiser->mc_running_avg_y[0])));

  for (layer = 0; layer < num_layers; ++layer) {
    const int denoise_width = (layer == 0) ? width : scaled_width;
    const int denoise_height = (layer == 0) ? height : scaled_height;
    for (i = 0; i < init_num_ref_frames; ++i) {
      fail = vpx_alloc_frame_buffer(
          &denoiser->running_avg_y[i + denoiser->num_ref_frames * layer],
          denoise_width, denoise_height, ssx, ssy,
#if CONFIG_VP9_HIGHBITDEPTH
          use_highbitdepth,
#endif
          border, legacy_byte_alignment);
      if (fail) {
        vp9_denoiser_free(denoiser);
        return 1;
      }
#ifdef OUTPUT_YUV_DENOISED
      make_grayscale(&denoiser->running_avg_y[i]);
#endif
    }

    fail = vpx_alloc_frame_buffer(&denoiser->mc_running_avg_y[layer],
                                  denoise_width, denoise_height, ssx, ssy,
#if CONFIG_VP9_HIGHBITDEPTH
                                  use_highbitdepth,
#endif
                                  border, legacy_byte_alignment);
    if (fail) {
      vp9_denoiser_free(denoiser);
      return 1;
    }
  }

  // denoiser->last_source only used for noise_estimation, so only for top
  // layer.
  fail = vpx_alloc_frame_buffer(&denoiser->last_source, width, height, ssx, ssy,
#if CONFIG_VP9_HIGHBITDEPTH
                                use_highbitdepth,
#endif
                                border, legacy_byte_alignment);
  if (fail) {
    vp9_denoiser_free(denoiser);
    return 1;
  }
#ifdef OUTPUT_YUV_DENOISED
  make_grayscale(&denoiser->running_avg_y[i]);
#endif
  denoiser->frame_buffer_initialized = 1;
  denoiser->denoising_level = kDenLow;
  denoiser->prev_denoising_level = kDenLow;
  denoiser->reset = 0;
  return 0;
}

void vp9_denoiser_free(VP9_DENOISER *denoiser) {
  int i;
  if (denoiser == NULL) {
    return;
  }
  denoiser->frame_buffer_initialized = 0;
  for (i = 0; i < denoiser->num_ref_frames * denoiser->num_layers; ++i) {
    vpx_free_frame_buffer(&denoiser->running_avg_y[i]);
  }
  vpx_free(denoiser->running_avg_y);
  denoiser->running_avg_y = NULL;

  for (i = 0; i < denoiser->num_layers; ++i) {
    vpx_free_frame_buffer(&denoiser->mc_running_avg_y[i]);
  }

  vpx_free(denoiser->mc_running_avg_y);
  denoiser->mc_running_avg_y = NULL;
  vpx_free_frame_buffer(&denoiser->last_source);
}

void vp9_denoiser_set_noise_level(VP9_DENOISER *denoiser, int noise_level) {
  denoiser->denoising_level = noise_level;
  if (denoiser->denoising_level > kDenLowLow &&
      denoiser->prev_denoising_level == kDenLowLow)
    denoiser->reset = 1;
  else
    denoiser->reset = 0;
  denoiser->prev_denoising_level = denoiser->denoising_level;
}

// Scale/increase the partition threshold
// for denoiser speed-up.
int64_t vp9_scale_part_thresh(int64_t threshold, VP9_DENOISER_LEVEL noise_level,
                              int content_state, int temporal_layer_id) {
  if ((content_state == kLowSadLowSumdiff) ||
      (content_state == kHighSadLowSumdiff) ||
      (content_state == kLowVarHighSumdiff) || (noise_level == kDenHigh) ||
      (temporal_layer_id != 0)) {
    int64_t scaled_thr =
        (temporal_layer_id < 2) ? (3 * threshold) >> 1 : (7 * threshold) >> 2;
    return scaled_thr;
  } else {
    return (5 * threshold) >> 2;
  }
}

//  Scale/increase the ac skip threshold for
//  denoiser speed-up.
int64_t vp9_scale_acskip_thresh(int64_t threshold,
                                VP9_DENOISER_LEVEL noise_level, int abs_sumdiff,
                                int temporal_layer_id) {
  if (noise_level >= kDenLow && abs_sumdiff < 5)
    return threshold *=
           (noise_level == kDenLow) ? 2 : (temporal_layer_id == 2) ? 10 : 6;
  else
    return threshold;
}

void vp9_denoiser_update_ref_frame(VP9_COMP *const cpi) {
  VP9_COMMON *const cm = &cpi->common;
  SVC *const svc = &cpi->svc;
  if (cpi->oxcf.noise_sensitivity > 0 && denoise_svc(cpi) &&
      cpi->denoiser.denoising_level > kDenLowLow) {
    int svc_refresh_denoiser_buffers = 0;
    int denoise_svc_second_layer = 0;
    FRAME_TYPE frame_type = cm->intra_only ? KEY_FRAME : cm->frame_type;
    if (cpi->use_svc) {
      const int svc_buf_shift =
          svc->number_spatial_layers - svc->spatial_layer_id == 2
              ? cpi->denoiser.num_ref_frames
              : 0;
      int layer =
          LAYER_IDS_TO_IDX(svc->spatial_layer_id, svc->temporal_layer_id,
                           svc->number_temporal_layers);
      LAYER_CONTEXT *const lc = &svc->layer_context[layer];
      svc_refresh_denoiser_buffers =
          lc->is_key_frame || svc->spatial_layer_sync[svc->spatial_layer_id];
      denoise_svc_second_layer =
          svc->number_spatial_layers - svc->spatial_layer_id == 2 ? 1 : 0;
      // Check if we need to allocate extra buffers in the denoiser
      // for refreshed frames.
      if (vp9_denoiser_realloc_svc(cm, &cpi->denoiser, svc, svc_buf_shift,
                                   cpi->refresh_alt_ref_frame,
                                   cpi->refresh_golden_frame,
                                   cpi->refresh_last_frame, cpi->alt_fb_idx,
                                   cpi->gld_fb_idx, cpi->lst_fb_idx))
        vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
                           "Failed to re-allocate denoiser for SVC");
    }
    vp9_denoiser_update_frame_info(
        &cpi->denoiser, *cpi->Source, svc, frame_type,
        cpi->refresh_alt_ref_frame, cpi->refresh_golden_frame,
        cpi->refresh_last_frame, cpi->alt_fb_idx, cpi->gld_fb_idx,
        cpi->lst_fb_idx, cpi->resize_pending, svc_refresh_denoiser_buffers,
        denoise_svc_second_layer);
  }
}

#ifdef OUTPUT_YUV_DENOISED
static void make_grayscale(YV12_BUFFER_CONFIG *yuv) {
  int r, c;
  uint8_t *u = yuv->u_buffer;
  uint8_t *v = yuv->v_buffer;

  for (r = 0; r < yuv->uv_height; ++r) {
    for (c = 0; c < yuv->uv_width; ++c) {
      u[c] = UINT8_MAX / 2;
      v[c] = UINT8_MAX / 2;
    }
    u += yuv->uv_stride;
    v += yuv->uv_stride;
  }
}
#endif