granicus.if.org Git - libvpx/blob - vp8/encoder/denoising.c

   1 /*
   2  *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11 #include <limits.h>
  12
  13 #include "denoising.h"
  14
  15 #include "vp8/common/reconinter.h"
  16 #include "vpx/vpx_integer.h"
  17 #include "vpx_mem/vpx_mem.h"
  18 #include "vp8_rtcd.h"
  19
  20 static const unsigned int NOISE_MOTION_THRESHOLD = 25 * 25;
  21 /* SSE_DIFF_THRESHOLD is selected as ~95% confidence assuming
  22  * var(noise) ~= 100.
  23  */
  24 static const unsigned int SSE_DIFF_THRESHOLD = 16 * 16 * 20;
  25 static const unsigned int SSE_THRESHOLD = 16 * 16 * 40;
  26 static const unsigned int SSE_THRESHOLD_HIGH = 16 * 16 * 60;
  27
  28 /*
  29  * The filter function was modified to reduce the computational complexity.
  30  * Step 1:
  31  * Instead of applying tap coefficients for each pixel, we calculated the
  32  * pixel adjustments vs. pixel diff value ahead of time.
  33  *     adjustment = filtered_value - current_raw
  34  *                = (filter_coefficient * diff + 128) >> 8
  35  * where
  36  *     filter_coefficient = (255 << 8) / (256 + ((absdiff * 330) >> 3));
  37  *     filter_coefficient += filter_coefficient /
  38  *                           (3 + motion_magnitude_adjustment);
  39  *     filter_coefficient is clamped to 0 ~ 255.
  40  *
  41  * Step 2:
  42  * The adjustment vs. diff curve becomes flat very quick when diff increases.
  43  * This allowed us to use only several levels to approximate the curve without
  44  * changing the filtering algorithm too much.
  45  * The adjustments were further corrected by checking the motion magnitude.
  46  * The levels used are:
  47  * diff       adjustment w/o motion correction   adjustment w/ motion correction
  48  * [-255, -16]           -6                                   -7
  49  * [-15, -8]             -4                                   -5
  50  * [-7, -4]              -3                                   -4
  51  * [-3, 3]               diff                                 diff
  52  * [4, 7]                 3                                    4
  53  * [8, 15]                4                                    5
  54  * [16, 255]              6                                    7
  55  */
  56
  57 int vp8_denoiser_filter_c(unsigned char *mc_running_avg_y, int mc_avg_y_stride,
  58                           unsigned char *running_avg_y, int avg_y_stride,
  59                           unsigned char *sig, int sig_stride,
  60                           unsigned int motion_magnitude,
  61                           int increase_denoising)
  62 {
  63     unsigned char *running_avg_y_start = running_avg_y;
  64     unsigned char *sig_start = sig;
  65     int sum_diff_thresh;
  66     int r, c;
  67     int sum_diff = 0;
  68     int adj_val[3] = {3, 4, 6};
  69     int shift_inc1 = 0;
  70     int shift_inc2 = 1;
  71     /* If motion_magnitude is small, making the denoiser more aggressive by
  72      * increasing the adjustment for each level. Add another increment for
  73      * blocks that are labeled for increase denoising. */
  74     if (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD)
  75     {
  76       if (increase_denoising) {
  77         shift_inc1 = 1;
  78         shift_inc2 = 2;
  79       }
  80       adj_val[0] += shift_inc2;
  81       adj_val[1] += shift_inc2;
  82       adj_val[2] += shift_inc2;
  83     }
  84
  85     for (r = 0; r < 16; ++r)
  86     {
  87         for (c = 0; c < 16; ++c)
  88         {
  89             int diff = 0;
  90             int adjustment = 0;
  91             int absdiff = 0;
  92
  93             diff = mc_running_avg_y[c] - sig[c];
  94             absdiff = abs(diff);
  95
  96             // When |diff| <= |3 + shift_inc1|, use pixel value from
  97             // last denoised raw.
  98             if (absdiff <= 3 + shift_inc1)
  99             {
 100                 running_avg_y[c] = mc_running_avg_y[c];
 101                 sum_diff += diff;
 102             }
 103             else
 104             {
 105                 if (absdiff >= 4 && absdiff <= 7)
 106                     adjustment = adj_val[0];
 107                 else if (absdiff >= 8 && absdiff <= 15)
 108                     adjustment = adj_val[1];
 109                 else
 110                     adjustment = adj_val[2];
 111
 112                 if (diff > 0)
 113                 {
 114                     if ((sig[c] + adjustment) > 255)
 115                         running_avg_y[c] = 255;
 116                     else
 117                         running_avg_y[c] = sig[c] + adjustment;
 118
 119                     sum_diff += adjustment;
 120                 }
 121                 else
 122                 {
 123                     if ((sig[c] - adjustment) < 0)
 124                         running_avg_y[c] = 0;
 125                     else
 126                         running_avg_y[c] = sig[c] - adjustment;
 127
 128                     sum_diff -= adjustment;
 129                 }
 130             }
 131         }
 132
 133         /* Update pointers for next iteration. */
 134         sig += sig_stride;
 135         mc_running_avg_y += mc_avg_y_stride;
 136         running_avg_y += avg_y_stride;
 137     }
 138
 139     sum_diff_thresh= SUM_DIFF_THRESHOLD;
 140     if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH;
 141     if (abs(sum_diff) > sum_diff_thresh) {
 142       // Before returning to copy the block (i.e., apply no denoising), check
 143       // if we can still apply some (weaker) temporal filtering to this block,
 144       // that would otherwise not be denoised at all. Simplest is to apply
 145       // an additional adjustment to running_avg_y to bring it closer to sig.
 146       // The adjustment is capped by a maximum delta, and chosen such that
 147       // in most cases the resulting sum_diff will be within the
 148       // accceptable range given by sum_diff_thresh.
 149
 150       // The delta is set by the excess of absolute pixel diff over threshold.
 151       int delta = ((abs(sum_diff) - sum_diff_thresh) >> 8) + 1;
 152       // Only apply the adjustment for max delta up to 3.
 153       if (delta < 4) {
 154         sig -= sig_stride * 16;
 155         mc_running_avg_y -= mc_avg_y_stride * 16;
 156         running_avg_y -= avg_y_stride * 16;
 157         for (r = 0; r < 16; ++r) {
 158           for (c = 0; c < 16; ++c) {
 159             int diff = mc_running_avg_y[c] - sig[c];
 160             int adjustment = abs(diff);
 161             if (adjustment > delta)
 162               adjustment = delta;
 163             if (diff > 0) {
 164               // Bring denoised signal down.
 165               if (running_avg_y[c] - adjustment < 0)
 166                 running_avg_y[c] = 0;
 167               else
 168                 running_avg_y[c] = running_avg_y[c] - adjustment;
 169               sum_diff -= adjustment;
 170             } else if (diff < 0) {
 171               // Bring denoised signal up.
 172               if (running_avg_y[c] + adjustment > 255)
 173                 running_avg_y[c] = 255;
 174               else
 175                 running_avg_y[c] = running_avg_y[c] + adjustment;
 176               sum_diff += adjustment;
 177             }
 178           }
 179           // TODO(marpan): Check here if abs(sum_diff) has gone below the
 180           // threshold sum_diff_thresh, and if so, we can exit the row loop.
 181           sig += sig_stride;
 182           mc_running_avg_y += mc_avg_y_stride;
 183           running_avg_y += avg_y_stride;
 184         }
 185         if (abs(sum_diff) > sum_diff_thresh)
 186           return COPY_BLOCK;
 187       } else {
 188         return COPY_BLOCK;
 189       }
 190     }
 191
 192     vp8_copy_mem16x16(running_avg_y_start, avg_y_stride, sig_start, sig_stride);
 193     return FILTER_BLOCK;
 194 }
 195
 196 int vp8_denoiser_filter_uv_c(unsigned char *mc_running_avg_uv,
 197                              int mc_avg_uv_stride,
 198                              unsigned char *running_avg_uv,
 199                              int avg_uv_stride,
 200                              unsigned char *sig,
 201                              int sig_stride,
 202                              unsigned int motion_magnitude,
 203                              int increase_denoising) {
 204     unsigned char *running_avg_uv_start = running_avg_uv;
 205     unsigned char *sig_start = sig;
 206     int sum_diff_thresh;
 207     int r, c;
 208     int sum_diff = 0;
 209     int sum_block = 0;
 210     int adj_val[3] = {3, 4, 6};
 211     int shift_inc1 = 0;
 212     int shift_inc2 = 1;
 213     /* If motion_magnitude is small, making the denoiser more aggressive by
 214      * increasing the adjustment for each level. Add another increment for
 215      * blocks that are labeled for increase denoising. */
 216     if (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD_UV) {
 217       if (increase_denoising) {
 218         shift_inc1 = 1;
 219         shift_inc2 = 2;
 220       }
 221       adj_val[0] += shift_inc2;
 222       adj_val[1] += shift_inc2;
 223       adj_val[2] += shift_inc2;
 224     }
 225
 226     // Avoid denoising color signal if its close to average level.
 227     for (r = 0; r < 8; ++r) {
 228       for (c = 0; c < 8; ++c) {
 229         sum_block += sig[c];
 230       }
 231       sig += sig_stride;
 232     }
 233     if (abs(sum_block - (128 * 8 * 8)) < SUM_DIFF_FROM_AVG_THRESH_UV) {
 234       return COPY_BLOCK;
 235     }
 236
 237     sig -= sig_stride * 8;
 238     for (r = 0; r < 8; ++r) {
 239       for (c = 0; c < 8; ++c) {
 240         int diff = 0;
 241         int adjustment = 0;
 242         int absdiff = 0;
 243
 244         diff = mc_running_avg_uv[c] - sig[c];
 245         absdiff = abs(diff);
 246
 247         // When |diff| <= |3 + shift_inc1|, use pixel value from
 248         // last denoised raw.
 249         if (absdiff <= 3 + shift_inc1) {
 250           running_avg_uv[c] = mc_running_avg_uv[c];
 251           sum_diff += diff;
 252         } else {
 253           if (absdiff >= 4 && absdiff <= 7)
 254             adjustment = adj_val[0];
 255           else if (absdiff >= 8 && absdiff <= 15)
 256             adjustment = adj_val[1];
 257           else
 258             adjustment = adj_val[2];
 259           if (diff > 0) {
 260             if ((sig[c] + adjustment) > 255)
 261               running_avg_uv[c] = 255;
 262             else
 263               running_avg_uv[c] = sig[c] + adjustment;
 264             sum_diff += adjustment;
 265           } else {
 266             if ((sig[c] - adjustment) < 0)
 267               running_avg_uv[c] = 0;
 268             else
 269               running_avg_uv[c] = sig[c] - adjustment;
 270             sum_diff -= adjustment;
 271           }
 272         }
 273       }
 274       /* Update pointers for next iteration. */
 275       sig += sig_stride;
 276       mc_running_avg_uv += mc_avg_uv_stride;
 277       running_avg_uv += avg_uv_stride;
 278     }
 279
 280     sum_diff_thresh= SUM_DIFF_THRESHOLD_UV;
 281     if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH_UV;
 282     if (abs(sum_diff) > sum_diff_thresh) {
 283       // Before returning to copy the block (i.e., apply no denoising), check
 284       // if we can still apply some (weaker) temporal filtering to this block,
 285       // that would otherwise not be denoised at all. Simplest is to apply
 286       // an additional adjustment to running_avg_y to bring it closer to sig.
 287       // The adjustment is capped by a maximum delta, and chosen such that
 288       // in most cases the resulting sum_diff will be within the
 289       // accceptable range given by sum_diff_thresh.
 290
 291       // The delta is set by the excess of absolute pixel diff over threshold.
 292       int delta = ((abs(sum_diff) - sum_diff_thresh) >> 8) + 1;
 293       // Only apply the adjustment for max delta up to 3.
 294       if (delta < 4) {
 295         sig -= sig_stride * 8;
 296         mc_running_avg_uv -= mc_avg_uv_stride * 8;
 297         running_avg_uv -= avg_uv_stride * 8;
 298         for (r = 0; r < 8; ++r) {
 299           for (c = 0; c < 8; ++c) {
 300             int diff = mc_running_avg_uv[c] - sig[c];
 301             int adjustment = abs(diff);
 302             if (adjustment > delta)
 303               adjustment = delta;
 304             if (diff > 0) {
 305               // Bring denoised signal down.
 306               if (running_avg_uv[c] - adjustment < 0)
 307                 running_avg_uv[c] = 0;
 308               else
 309                 running_avg_uv[c] = running_avg_uv[c] - adjustment;
 310               sum_diff -= adjustment;
 311             } else if (diff < 0) {
 312               // Bring denoised signal up.
 313               if (running_avg_uv[c] + adjustment > 255)
 314                 running_avg_uv[c] = 255;
 315               else
 316                 running_avg_uv[c] = running_avg_uv[c] + adjustment;
 317               sum_diff += adjustment;
 318             }
 319           }
 320           // TODO(marpan): Check here if abs(sum_diff) has gone below the
 321           // threshold sum_diff_thresh, and if so, we can exit the row loop.
 322           sig += sig_stride;
 323           mc_running_avg_uv += mc_avg_uv_stride;
 324           running_avg_uv += avg_uv_stride;
 325         }
 326         if (abs(sum_diff) > sum_diff_thresh)
 327           return COPY_BLOCK;
 328       } else {
 329         return COPY_BLOCK;
 330       }
 331     }
 332
 333     vp8_copy_mem8x8(running_avg_uv_start, avg_uv_stride, sig_start,
 334                     sig_stride);
 335     return FILTER_BLOCK;
 336 }
 337
 338 void vp8_denoiser_set_parameters(VP8_DENOISER *denoiser, int mode) {
 339   assert(mode > 0);  // Denoiser is allocated only if mode > 0.
 340   if (mode == 1) {
 341     denoiser->denoiser_mode = kDenoiserOnYOnly;
 342   } else if (mode == 2) {
 343     denoiser->denoiser_mode = kDenoiserOnYUV;
 344   } else if (mode == 3) {
 345     denoiser->denoiser_mode = kDenoiserOnYUVAggressive;
 346   } else {
 347     denoiser->denoiser_mode = kDenoiserOnAdaptive;
 348   }
 349   if (denoiser->denoiser_mode != kDenoiserOnYUVAggressive) {
 350     denoiser->denoise_pars.scale_sse_thresh = 1;
 351     denoiser->denoise_pars.scale_motion_thresh = 8;
 352     denoiser->denoise_pars.scale_increase_filter = 0;
 353     denoiser->denoise_pars.denoise_mv_bias = 95;
 354     denoiser->denoise_pars.pickmode_mv_bias = 100;
 355     denoiser->denoise_pars.qp_thresh = 0;
 356     denoiser->denoise_pars.consec_zerolast = UINT_MAX;
 357   } else {
 358     denoiser->denoise_pars.scale_sse_thresh = 2;
 359     denoiser->denoise_pars.scale_motion_thresh = 16;
 360     denoiser->denoise_pars.scale_increase_filter = 1;
 361     denoiser->denoise_pars.denoise_mv_bias = 60;
 362     denoiser->denoise_pars.pickmode_mv_bias = 60;
 363     denoiser->denoise_pars.qp_thresh = 100;
 364     denoiser->denoise_pars.consec_zerolast = 10;
 365   }
 366 }
 367
 368 int vp8_denoiser_allocate(VP8_DENOISER *denoiser, int width, int height,
 369                           int num_mb_rows, int num_mb_cols, int mode)
 370 {
 371     int i;
 372     assert(denoiser);
 373     denoiser->num_mb_cols = num_mb_cols;
 374
 375     for (i = 0; i < MAX_REF_FRAMES; i++)
 376     {
 377         denoiser->yv12_running_avg[i].flags = 0;
 378
 379         if (vp8_yv12_alloc_frame_buffer(&(denoiser->yv12_running_avg[i]), width,
 380                                         height, VP8BORDERINPIXELS)
 381             < 0)
 382         {
 383             vp8_denoiser_free(denoiser);
 384             return 1;
 385         }
 386         vpx_memset(denoiser->yv12_running_avg[i].buffer_alloc, 0,
 387                    denoiser->yv12_running_avg[i].frame_size);
 388
 389     }
 390     denoiser->yv12_mc_running_avg.flags = 0;
 391
 392     if (vp8_yv12_alloc_frame_buffer(&(denoiser->yv12_mc_running_avg), width,
 393                                    height, VP8BORDERINPIXELS) < 0)
 394     {
 395         vp8_denoiser_free(denoiser);
 396         return 1;
 397     }
 398
 399     vpx_memset(denoiser->yv12_mc_running_avg.buffer_alloc, 0,
 400                denoiser->yv12_mc_running_avg.frame_size);
 401
 402     if (vp8_yv12_alloc_frame_buffer(&denoiser->yv12_last_source, width,
 403                                     height, VP8BORDERINPIXELS) < 0) {
 404       vp8_denoiser_free(denoiser);
 405       return 1;
 406     }
 407     vpx_memset(denoiser->yv12_last_source.buffer_alloc, 0,
 408                denoiser->yv12_last_source.frame_size);
 409
 410     denoiser->denoise_state = vpx_calloc((num_mb_rows * num_mb_cols), 1);
 411     vpx_memset(denoiser->denoise_state, 0, (num_mb_rows * num_mb_cols));
 412     vp8_denoiser_set_parameters(denoiser, mode);
 413     denoiser->nmse_source_diff = 0;
 414     denoiser->nmse_source_diff_count = 0;
 415     // TODO(marpan): Adjust thresholds, including effect on resolution.
 416     denoiser->threshold_aggressive_mode = 40;
 417     if (width * height > 640 * 480)
 418       denoiser->threshold_aggressive_mode = 180;
 419     return 0;
 420 }
 421
 422
 423 void vp8_denoiser_free(VP8_DENOISER *denoiser)
 424 {
 425     int i;
 426     assert(denoiser);
 427
 428     for (i = 0; i < MAX_REF_FRAMES ; i++)
 429     {
 430         vp8_yv12_de_alloc_frame_buffer(&denoiser->yv12_running_avg[i]);
 431     }
 432     vp8_yv12_de_alloc_frame_buffer(&denoiser->yv12_mc_running_avg);
 433     vpx_free(denoiser->denoise_state);
 434 }
 435
 436
 437 void vp8_denoiser_denoise_mb(VP8_DENOISER *denoiser,
 438                              MACROBLOCK *x,
 439                              unsigned int best_sse,
 440                              unsigned int zero_mv_sse,
 441                              int recon_yoffset,
 442                              int recon_uvoffset,
 443                              loop_filter_info_n *lfi_n,
 444                              int mb_row,
 445                              int mb_col,
 446                              int block_index)
 447
 448 {
 449     int mv_row;
 450     int mv_col;
 451     unsigned int motion_threshold;
 452     unsigned int motion_magnitude2;
 453     unsigned int sse_thresh;
 454     int sse_diff_thresh = 0;
 455     // Spatial loop filter: only applied selectively based on
 456     // temporal filter state of block relative to top/left neighbors.
 457     int apply_spatial_loop_filter = 1;
 458     MV_REFERENCE_FRAME frame = x->best_reference_frame;
 459     MV_REFERENCE_FRAME zero_frame = x->best_zeromv_reference_frame;
 460
 461     enum vp8_denoiser_decision decision = FILTER_BLOCK;
 462     enum vp8_denoiser_decision decision_u = COPY_BLOCK;
 463     enum vp8_denoiser_decision decision_v = COPY_BLOCK;
 464
 465     if (zero_frame)
 466     {
 467         YV12_BUFFER_CONFIG *src = &denoiser->yv12_running_avg[frame];
 468         YV12_BUFFER_CONFIG *dst = &denoiser->yv12_mc_running_avg;
 469         YV12_BUFFER_CONFIG saved_pre,saved_dst;
 470         MB_MODE_INFO saved_mbmi;
 471         MACROBLOCKD *filter_xd = &x->e_mbd;
 472         MB_MODE_INFO *mbmi = &filter_xd->mode_info_context->mbmi;
 473         int sse_diff = 0;
 474         // Bias on zero motion vector sse.
 475         const int zero_bias = denoiser->denoise_pars.denoise_mv_bias;
 476         zero_mv_sse = (unsigned int)((int64_t)zero_mv_sse * zero_bias / 100);
 477         sse_diff = zero_mv_sse - best_sse;
 478
 479         saved_mbmi = *mbmi;
 480
 481         /* Use the best MV for the compensation. */
 482         mbmi->ref_frame = x->best_reference_frame;
 483         mbmi->mode = x->best_sse_inter_mode;
 484         mbmi->mv = x->best_sse_mv;
 485         mbmi->need_to_clamp_mvs = x->need_to_clamp_best_mvs;
 486         mv_col = x->best_sse_mv.as_mv.col;
 487         mv_row = x->best_sse_mv.as_mv.row;
 488         // Bias to zero_mv if small amount of motion.
 489         // Note sse_diff_thresh is intialized to zero, so this ensures
 490         // we will always choose zero_mv for denoising if
 491         // zero_mv_see <= best_sse (i.e., sse_diff <= 0).
 492         if ((unsigned int)(mv_row * mv_row + mv_col * mv_col)
 493             <= NOISE_MOTION_THRESHOLD)
 494             sse_diff_thresh = (int)SSE_DIFF_THRESHOLD;
 495
 496         if (frame == INTRA_FRAME ||
 497             sse_diff <= sse_diff_thresh)
 498         {
 499             /*
 500              * Handle intra blocks as referring to last frame with zero motion
 501              * and let the absolute pixel difference affect the filter factor.
 502              * Also consider small amount of motion as being random walk due
 503              * to noise, if it doesn't mean that we get a much bigger error.
 504              * Note that any changes to the mode info only affects the
 505              * denoising.
 506              */
 507             mbmi->ref_frame =
 508                     x->best_zeromv_reference_frame;
 509
 510             src = &denoiser->yv12_running_avg[zero_frame];
 511
 512             mbmi->mode = ZEROMV;
 513             mbmi->mv.as_int = 0;
 514             x->best_sse_inter_mode = ZEROMV;
 515             x->best_sse_mv.as_int = 0;
 516             best_sse = zero_mv_sse;
 517         }
 518
 519         saved_pre = filter_xd->pre;
 520         saved_dst = filter_xd->dst;
 521
 522         /* Compensate the running average. */
 523         filter_xd->pre.y_buffer = src->y_buffer + recon_yoffset;
 524         filter_xd->pre.u_buffer = src->u_buffer + recon_uvoffset;
 525         filter_xd->pre.v_buffer = src->v_buffer + recon_uvoffset;
 526         /* Write the compensated running average to the destination buffer. */
 527         filter_xd->dst.y_buffer = dst->y_buffer + recon_yoffset;
 528         filter_xd->dst.u_buffer = dst->u_buffer + recon_uvoffset;
 529         filter_xd->dst.v_buffer = dst->v_buffer + recon_uvoffset;
 530
 531         if (!x->skip)
 532         {
 533             vp8_build_inter_predictors_mb(filter_xd);
 534         }
 535         else
 536         {
 537             vp8_build_inter16x16_predictors_mb(filter_xd,
 538                                                filter_xd->dst.y_buffer,
 539                                                filter_xd->dst.u_buffer,
 540                                                filter_xd->dst.v_buffer,
 541                                                filter_xd->dst.y_stride,
 542                                                filter_xd->dst.uv_stride);
 543         }
 544         filter_xd->pre = saved_pre;
 545         filter_xd->dst = saved_dst;
 546         *mbmi = saved_mbmi;
 547
 548     }
 549
 550     mv_row = x->best_sse_mv.as_mv.row;
 551     mv_col = x->best_sse_mv.as_mv.col;
 552     motion_magnitude2 = mv_row * mv_row + mv_col * mv_col;
 553     motion_threshold = denoiser->denoise_pars.scale_motion_thresh *
 554         NOISE_MOTION_THRESHOLD;
 555
 556     if (motion_magnitude2 <
 557         denoiser->denoise_pars.scale_increase_filter * NOISE_MOTION_THRESHOLD)
 558       x->increase_denoising = 1;
 559
 560     sse_thresh = denoiser->denoise_pars.scale_sse_thresh * SSE_THRESHOLD;
 561     if (x->increase_denoising)
 562       sse_thresh = denoiser->denoise_pars.scale_sse_thresh * SSE_THRESHOLD_HIGH;
 563
 564     if (best_sse > sse_thresh || motion_magnitude2 > motion_threshold)
 565       decision = COPY_BLOCK;
 566
 567     if (decision == FILTER_BLOCK)
 568     {
 569         unsigned char *mc_running_avg_y =
 570             denoiser->yv12_mc_running_avg.y_buffer + recon_yoffset;
 571         int mc_avg_y_stride = denoiser->yv12_mc_running_avg.y_stride;
 572         unsigned char *running_avg_y =
 573             denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset;
 574         int avg_y_stride = denoiser->yv12_running_avg[INTRA_FRAME].y_stride;
 575
 576         /* Filter. */
 577         decision = vp8_denoiser_filter(mc_running_avg_y, mc_avg_y_stride,
 578                                        running_avg_y, avg_y_stride,
 579                                        x->thismb, 16, motion_magnitude2,
 580                                        x->increase_denoising);
 581         denoiser->denoise_state[block_index] = motion_magnitude2 > 0 ?
 582             kFilterNonZeroMV : kFilterZeroMV;
 583         // Only denoise UV for zero motion, and if y channel was denoised.
 584         if (denoiser->denoiser_mode != kDenoiserOnYOnly &&
 585             motion_magnitude2 == 0 &&
 586             decision == FILTER_BLOCK) {
 587           unsigned char *mc_running_avg_u =
 588               denoiser->yv12_mc_running_avg.u_buffer + recon_uvoffset;
 589           unsigned char *running_avg_u =
 590               denoiser->yv12_running_avg[INTRA_FRAME].u_buffer + recon_uvoffset;
 591           unsigned char *mc_running_avg_v =
 592               denoiser->yv12_mc_running_avg.v_buffer + recon_uvoffset;
 593           unsigned char *running_avg_v =
 594               denoiser->yv12_running_avg[INTRA_FRAME].v_buffer + recon_uvoffset;
 595           int mc_avg_uv_stride = denoiser->yv12_mc_running_avg.uv_stride;
 596           int avg_uv_stride = denoiser->yv12_running_avg[INTRA_FRAME].uv_stride;
 597           int signal_stride = x->block[16].src_stride;
 598           decision_u =
 599               vp8_denoiser_filter_uv(mc_running_avg_u, mc_avg_uv_stride,
 600                                       running_avg_u, avg_uv_stride,
 601                                       x->block[16].src + *x->block[16].base_src,
 602                                       signal_stride, motion_magnitude2, 0);
 603           decision_v =
 604               vp8_denoiser_filter_uv(mc_running_avg_v, mc_avg_uv_stride,
 605                                       running_avg_v, avg_uv_stride,
 606                                       x->block[20].src + *x->block[20].base_src,
 607                                       signal_stride, motion_magnitude2, 0);
 608         }
 609     }
 610     if (decision == COPY_BLOCK)
 611     {
 612         /* No filtering of this block; it differs too much from the predictor,
 613          * or the motion vector magnitude is considered too big.
 614          */
 615         vp8_copy_mem16x16(
 616                 x->thismb, 16,
 617                 denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
 618                 denoiser->yv12_running_avg[INTRA_FRAME].y_stride);
 619         denoiser->denoise_state[block_index] = kNoFilter;
 620     }
 621     if (denoiser->denoiser_mode != kDenoiserOnYOnly) {
 622       if (decision_u == COPY_BLOCK) {
 623         vp8_copy_mem8x8(
 624             x->block[16].src + *x->block[16].base_src, x->block[16].src_stride,
 625             denoiser->yv12_running_avg[INTRA_FRAME].u_buffer + recon_uvoffset,
 626             denoiser->yv12_running_avg[INTRA_FRAME].uv_stride);
 627       }
 628       if (decision_v == COPY_BLOCK) {
 629         vp8_copy_mem8x8(
 630             x->block[20].src + *x->block[20].base_src, x->block[16].src_stride,
 631             denoiser->yv12_running_avg[INTRA_FRAME].v_buffer + recon_uvoffset,
 632             denoiser->yv12_running_avg[INTRA_FRAME].uv_stride);
 633       }
 634     }
 635     // Option to selectively deblock the denoised signal, for y channel only.
 636     if (apply_spatial_loop_filter) {
 637       loop_filter_info lfi;
 638       int apply_filter_col = 0;
 639       int apply_filter_row = 0;
 640       int apply_filter = 0;
 641       int y_stride = denoiser->yv12_running_avg[INTRA_FRAME].y_stride;
 642       int uv_stride =denoiser->yv12_running_avg[INTRA_FRAME].uv_stride;
 643
 644       // Fix filter level to some nominal value for now.
 645       int filter_level = 32;
 646
 647       int hev_index = lfi_n->hev_thr_lut[INTER_FRAME][filter_level];
 648       lfi.mblim = lfi_n->mblim[filter_level];
 649       lfi.blim = lfi_n->blim[filter_level];
 650       lfi.lim = lfi_n->lim[filter_level];
 651       lfi.hev_thr = lfi_n->hev_thr[hev_index];
 652
 653       // Apply filter if there is a difference in the denoiser filter state
 654       // between the current and left/top block, or if non-zero motion vector
 655       // is used for the motion-compensated filtering.
 656       if (mb_col > 0) {
 657         apply_filter_col = !((denoiser->denoise_state[block_index] ==
 658             denoiser->denoise_state[block_index - 1]) &&
 659             denoiser->denoise_state[block_index] != kFilterNonZeroMV);
 660         if (apply_filter_col) {
 661           // Filter left vertical edge.
 662           apply_filter = 1;
 663           vp8_loop_filter_mbv(
 664               denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
 665               NULL, NULL, y_stride, uv_stride, &lfi);
 666         }
 667       }
 668       if (mb_row > 0) {
 669         apply_filter_row = !((denoiser->denoise_state[block_index] ==
 670             denoiser->denoise_state[block_index - denoiser->num_mb_cols]) &&
 671             denoiser->denoise_state[block_index] != kFilterNonZeroMV);
 672         if (apply_filter_row) {
 673           // Filter top horizontal edge.
 674           apply_filter = 1;
 675           vp8_loop_filter_mbh(
 676               denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
 677               NULL, NULL, y_stride, uv_stride, &lfi);
 678         }
 679       }
 680       if (apply_filter) {
 681         // Update the signal block |x|. Pixel changes are only to top and/or
 682         // left boundary pixels: can we avoid full block copy here.
 683         vp8_copy_mem16x16(
 684             denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
 685             y_stride, x->thismb, 16);
 686       }
 687     }
 688 }