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av1_temporal_denoiser.c (28975B)

---

/*
* Copyright (c) 2020, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/

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

#include "config/aom_dsp_rtcd.h"
#include "aom_dsp/aom_dsp_common.h"
#include "aom_scale/yv12config.h"
#include "aom/aom_integer.h"
#include "av1/common/reconinter.h"
#include "av1/encoder/reconinter_enc.h"
#include "av1/encoder/context_tree.h"
#include "av1/encoder/av1_temporal_denoiser.h"
#include "av1/encoder/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(kyslov): 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 av1_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 < block_size_high[bs]; ++r) {
   for (c = 0; c < block_size_wide[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] = AOMMIN(UINT8_MAX, sig[c] + adj);
         total_adj += adj;
       } else {
         avg[c] = AOMMAX(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 < block_size_high[bs]; ++r) {
   for (c = 0; c < block_size_wide[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] = AOMMAX(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] = AOMMIN(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 << 2) + (mi_col << 2);
}

static AV1_DENOISER_DECISION perform_motion_compensation(
   AV1_COMMON *const cm, AV1_DENOISER *denoiser, MACROBLOCK *mb, BLOCK_SIZE bs,
   int increase_denoising, int mi_row, int mi_col, PICK_MODE_CONTEXT *ctx,
   int motion_magnitude, int *zeromv_filter, 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;
 MB_MODE_INFO *mi = filter_mbd->mi[0];
 MB_MODE_INFO saved_mi;
 int i;
 struct buf_2d saved_dst[MAX_MB_PLANE];
 struct buf_2d saved_pre[MAX_MB_PLANE];
 // const RefBuffer *saved_block_refs[2];
 MV_REFERENCE_FRAME saved_frame;

 frame = ctx->best_reference_frame;

 saved_mi = *mi;

 // 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 &&
     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 == GOLDEN_FRAME && use_gf_temporal_ref) ||
       (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 = GLOBALMV;
   mi->mv[0].as_int = 0;
   ctx->best_sse_inter_mode = GLOBALMV;
   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;
 }

 // Set the pointers in the MACROBLOCKD to point to the buffers in the denoiser
 // struct.
 set_ref_ptrs(cm, filter_mbd, saved_frame, NONE);
 av1_setup_pre_planes(filter_mbd, 0, &(denoiser->running_avg_y[frame]), mi_row,
                      mi_col, filter_mbd->block_ref_scale_factors[0], 1);
 av1_setup_dst_planes(filter_mbd->plane, bs,
                      &(denoiser->mc_running_avg_y[denoise_layer_idx]), mi_row,
                      mi_col, 0, 1);

 av1_enc_build_inter_predictor_y(filter_mbd, mi_row, mi_col);

 // Restore everything to its original state
 *mi = saved_mi;
 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 av1_denoiser_denoise(AV1_COMP *cpi, MACROBLOCK *mb, int mi_row, int mi_col,
                         BLOCK_SIZE bs, PICK_MODE_CONTEXT *ctx,
                         AV1_DENOISER_DECISION *denoiser_decision,
                         int use_gf_temporal_ref) {
 int mv_col, mv_row;
 int motion_magnitude = 0;
 int zeromv_filter = 0;
 AV1_DENOISER *denoiser = &cpi->denoiser;
 AV1_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 increase_denoising = 0;
 int last_is_reference = cpi->ref_frame_flags & AOM_LAST_FLAG;
 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 (denoiser->denoising_level == kDenHigh) increase_denoising = 1;

 // Copy block if LAST_FRAME is not a reference.
 // Last doesn't always exist when SVC layers are dynamically changed, e.g. top
 // spatial layer doesn't have last reference when it's brought up for the
 // first time on the fly.
 if (last_is_reference && 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, &zeromv_filter, cpi->svc.number_spatial_layers,
       cpi->source->y_width, cpi->ppi->rtc_ref.ref_idx[0],
       cpi->ppi->rtc_ref.ref_idx[3], cpi->ppi->use_svc,
       cpi->svc.spatial_layer_id, use_gf_temporal_ref);

 if (decision == FILTER_BLOCK) {
   decision = av1_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) {
   aom_convolve_copy(avg_start, avg.y_stride, src.buf, src.stride,
                     block_size_wide[bs], block_size_high[bs]);
 } else {  // COPY_BLOCK
   aom_convolve_copy(src.buf, src.stride, avg_start, avg.y_stride,
                     block_size_wide[bs], block_size_high[bs]);
 }
 *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 av1_denoiser_update_frame_info(
   AV1_DENOISER *denoiser, YV12_BUFFER_CONFIG src, struct RTC_REF *rtc_ref,
   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 (rtc_ref->set_ref_frame_config) {
   int i;
   for (i = 0; i < REF_FRAMES; i++) {
     if (rtc_ref->refresh[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 av1_denoiser_reset_frame_stats(PICK_MODE_CONTEXT *ctx) {
 ctx->zeromv_sse = INT64_MAX;
 ctx->newmv_sse = INT64_MAX;
 ctx->zeromv_lastref_sse = INT64_MAX;
 ctx->best_sse_mv.as_int = 0;
}

void av1_denoiser_update_frame_stats(MB_MODE_INFO *mi, int64_t 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 av1_denoiser_realloc_svc_helper(AV1_COMMON *cm,
                                          AV1_DENOISER *denoiser, int fb_idx) {
 int fail = 0;
 if (denoiser->running_avg_y[fb_idx].buffer_alloc == NULL) {
   fail = aom_alloc_frame_buffer(
       &denoiser->running_avg_y[fb_idx], cm->width, cm->height,
       cm->seq_params->subsampling_x, cm->seq_params->subsampling_y,
       cm->seq_params->use_highbitdepth, AOM_BORDER_IN_PIXELS,
       cm->features.byte_alignment, false, 0);
   if (fail) {
     av1_denoiser_free(denoiser);
     return 1;
   }
 }
 return 0;
}

int av1_denoiser_realloc_svc(AV1_COMMON *cm, AV1_DENOISER *denoiser,
                            struct RTC_REF *rtc_ref, 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 (rtc_ref->set_ref_frame_config) {
   int i;
   for (i = 0; i < REF_FRAMES; i++) {
     if (cm->current_frame.frame_type == KEY_FRAME ||
         rtc_ref->refresh[svc->spatial_layer_id] & (1 << i)) {
       fail = av1_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 = av1_denoiser_realloc_svc_helper(cm, denoiser,
                                            alt_fb_idx + 1 + svc_buf_shift);
     if (fail) return 1;
   }
   if (refresh_gld) {
     fail = av1_denoiser_realloc_svc_helper(cm, denoiser,
                                            gld_fb_idx + 1 + svc_buf_shift);
     if (fail) return 1;
   }
   if (refresh_lst) {
     fail = av1_denoiser_realloc_svc_helper(cm, denoiser,
                                            lst_fb_idx + 1 + svc_buf_shift);
     if (fail) return 1;
   }
 }
 return 0;
}

int av1_denoiser_alloc(AV1_COMMON *cm, struct SVC *svc, AV1_DENOISER *denoiser,
                      int use_svc, int noise_sen, int width, int height,
                      int ssx, int ssy, int use_highbitdepth, 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];
   av1_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 = AOMMAX(svc->number_spatial_layers - 2, 0);
   else
     // Only denoise the top spatial layer.
     svc->first_layer_denoise = AOMMAX(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 ? REF_FRAMES : NONSVC_REF_FRAMES;
 denoiser->num_layers = num_layers;
 CHECK_MEM_ERROR(cm, denoiser->running_avg_y,
                 aom_calloc(denoiser->num_ref_frames * num_layers,
                            sizeof(denoiser->running_avg_y[0])));
 CHECK_MEM_ERROR(
     cm, denoiser->mc_running_avg_y,
     aom_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 = aom_alloc_frame_buffer(
         &denoiser->running_avg_y[i + denoiser->num_ref_frames * layer],
         denoise_width, denoise_height, ssx, ssy, use_highbitdepth, border,
         legacy_byte_alignment, false, 0);
     if (fail) {
       av1_denoiser_free(denoiser);
       return 1;
     }
#ifdef OUTPUT_YUV_DENOISED
     make_grayscale(&denoiser->running_avg_y[i]);
#endif
   }

   fail = aom_alloc_frame_buffer(
       &denoiser->mc_running_avg_y[layer], denoise_width, denoise_height, ssx,
       ssy, use_highbitdepth, border, legacy_byte_alignment, false, 0);
   if (fail) {
     av1_denoiser_free(denoiser);
     return 1;
   }
 }

 // denoiser->last_source only used for noise_estimation, so only for top
 // layer.
 fail = aom_alloc_frame_buffer(&denoiser->last_source, width, height, ssx, ssy,
                               use_highbitdepth, border, legacy_byte_alignment,
                               false, 0);
 if (fail) {
   av1_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 = kDenMedium;
 denoiser->prev_denoising_level = kDenMedium;
 denoiser->reset = 0;
 denoiser->current_denoiser_frame = 0;
 return 0;
}

void av1_denoiser_free(AV1_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) {
   aom_free_frame_buffer(&denoiser->running_avg_y[i]);
 }
 aom_free(denoiser->running_avg_y);
 denoiser->running_avg_y = NULL;

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

 aom_free(denoiser->mc_running_avg_y);
 denoiser->mc_running_avg_y = NULL;
 aom_free_frame_buffer(&denoiser->last_source);
}

// TODO(kyslov) Enable when SVC temporal denosing is implemented
#if 0
static void force_refresh_longterm_ref(AV1_COMP *const cpi) {
 SVC *const svc = &cpi->svc;
 // If long term reference is used, force refresh of that slot, so
 // denoiser buffer for long term reference stays in sync.
 if (svc->use_gf_temporal_ref_current_layer) {
   int index = svc->spatial_layer_id;
   if (svc->number_spatial_layers == 3) index = svc->spatial_layer_id - 1;
   assert(index >= 0);
   cpi->alt_fb_idx = svc->buffer_gf_temporal_ref[index].idx;
   cpi->refresh_alt_ref_frame = 1;
 }
}
#endif

void av1_denoiser_set_noise_level(AV1_COMP *const cpi, int noise_level) {
 AV1_DENOISER *const denoiser = &cpi->denoiser;
 denoiser->denoising_level = noise_level;
 if (denoiser->denoising_level > kDenLowLow &&
     denoiser->prev_denoising_level == kDenLowLow) {
   denoiser->reset = 1;
// TODO(kyslov) Enable when SVC temporal denosing is implemented
#if 0
   force_refresh_longterm_ref(cpi);
#endif
 } else {
   denoiser->reset = 0;
 }
 denoiser->prev_denoising_level = denoiser->denoising_level;
}

// Scale/increase the partition threshold
// for denoiser speed-up.
int64_t av1_scale_part_thresh(int64_t threshold, AV1_DENOISER_LEVEL noise_level,
                             CONTENT_STATE_SB content_state,
                             int temporal_layer_id) {
 if ((content_state.source_sad_nonrd <= kLowSad &&
      content_state.low_sumdiff) ||
     (content_state.source_sad_nonrd == kHighSad &&
      content_state.low_sumdiff) ||
     (content_state.lighting_change && !content_state.low_sumdiff) ||
     (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 av1_scale_acskip_thresh(int64_t threshold,
                               AV1_DENOISER_LEVEL noise_level, int abs_sumdiff,
                               int temporal_layer_id) {
 if (noise_level >= kDenLow && abs_sumdiff < 5)
   threshold *= (noise_level == kDenLow)   ? 2
                : (temporal_layer_id == 2) ? 10
                                           : 6;
 return threshold;
}

void av1_denoiser_reset_on_first_frame(AV1_COMP *const cpi) {
 if (/*av1_denoise_svc_non_key(cpi) &&*/
     cpi->denoiser.current_denoiser_frame == 0) {
   cpi->denoiser.reset = 1;
// TODO(kyslov) Enable when SVC temporal denosing is implemented
#if 0
   force_refresh_longterm_ref(cpi);
#endif
 }
}

void av1_denoiser_update_ref_frame(AV1_COMP *const cpi) {
 AV1_COMMON *const cm = &cpi->common;
 RTC_REF *const rtc_ref = &cpi->ppi->rtc_ref;
 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->current_frame.frame_type == INTRA_ONLY_FRAME
                               ? KEY_FRAME
                               : cm->current_frame.frame_type;
   cpi->denoiser.current_denoiser_frame++;
   const int resize_pending = is_frame_resize_pending(cpi);

   if (cpi->ppi->use_svc) {
// TODO(kyslov) Enable when SVC temporal denosing is implemented
#if 0
     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 (av1_denoiser_realloc_svc(cm, &cpi->denoiser, rtc_ref,
                                  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))
       aom_internal_error(cm->error, AOM_CODEC_MEM_ERROR,
                          "Failed to re-allocate denoiser for SVC");
#endif
   }
   av1_denoiser_update_frame_info(
       &cpi->denoiser, *cpi->source, rtc_ref, svc, frame_type,
       cpi->refresh_frame.alt_ref_frame, cpi->refresh_frame.golden_frame, 1,
       rtc_ref->ref_idx[6], rtc_ref->ref_idx[3], rtc_ref->ref_idx[0],
       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;
 }
}

void aom_write_yuv_frame(FILE *yuv_file, YV12_BUFFER_CONFIG *s) {
 unsigned char *src = s->y_buffer;
 int h = s->y_crop_height;

 do {
   fwrite(src, s->y_width, 1, yuv_file);
   src += s->y_stride;
 } while (--h);

 src = s->u_buffer;
 h = s->uv_crop_height;

 do {
   fwrite(src, s->uv_width, 1, yuv_file);
   src += s->uv_stride;
 } while (--h);

 src = s->v_buffer;
 h = s->uv_crop_height;

 do {
   fwrite(src, s->uv_width, 1, yuv_file);
   src += s->uv_stride;
 } while (--h);
}
#endif