| /* |
| * Copyright (c) 2021, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 3-Clause Clear License |
| * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear |
| * License was not distributed with this source code in the LICENSE file, you |
| * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/. 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 |
| * aomedia.org/license/patent-license/. |
| */ |
| |
| #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/encoder/context_tree.h" |
| #include "av1/encoder/av1_noise_estimate.h" |
| #include "av1/encoder/encoder.h" |
| |
| void av1_noise_estimate_init(NOISE_ESTIMATE *const ne, int width, int height) { |
| ne->enabled = 0; |
| ne->level = (width * height < 1280 * 720) ? kLowLow : kLow; |
| ne->value = 0; |
| ne->count = 0; |
| ne->thresh = 90; |
| ne->last_w = 0; |
| ne->last_h = 0; |
| if (width * height >= 1920 * 1080) { |
| ne->thresh = 200; |
| } else if (width * height >= 1280 * 720) { |
| ne->thresh = 140; |
| } else if (width * height >= 640 * 360) { |
| ne->thresh = 115; |
| } |
| ne->num_frames_estimate = 15; |
| ne->adapt_thresh = (3 * ne->thresh) >> 1; |
| } |
| |
| static int enable_noise_estimation(AV1_COMP *const cpi) { |
| ResizePendingParams *const resize_pending_params = |
| &cpi->resize_pending_params; |
| const int resize_pending = |
| (resize_pending_params->width && resize_pending_params->height && |
| (cpi->common.width != resize_pending_params->width || |
| cpi->common.height != resize_pending_params->height)); |
| |
| (void)resize_pending; |
| /* if (cpi->common.seq_params.use_highbitdepth) */ return 0; |
| } |
| |
| #if CONFIG_AV1_TEMPORAL_DENOISING |
| static void copy_frame(YV12_BUFFER_CONFIG *const dest, |
| const YV12_BUFFER_CONFIG *const src) { |
| 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 (int r = 0; r < dest->y_height; ++r) { |
| memcpy(destbuf, srcbuf, dest->y_width); |
| destbuf += dest->y_stride; |
| srcbuf += src->y_stride; |
| } |
| } |
| #endif // CONFIG_AV1_TEMPORAL_DENOISING |
| |
| NOISE_LEVEL av1_noise_estimate_extract_level(NOISE_ESTIMATE *const ne) { |
| int noise_level = kLowLow; |
| if (ne->value > (ne->thresh << 1)) { |
| noise_level = kHigh; |
| } else { |
| if (ne->value > ne->thresh) |
| noise_level = kMedium; |
| else if (ne->value > (ne->thresh >> 1)) |
| noise_level = kLow; |
| else |
| noise_level = kLowLow; |
| } |
| return noise_level; |
| } |
| |
| void av1_update_noise_estimate(AV1_COMP *const cpi) { |
| const AV1_COMMON *const cm = &cpi->common; |
| const CommonModeInfoParams *const mi_params = &cm->mi_params; |
| |
| NOISE_ESTIMATE *const ne = &cpi->noise_estimate; |
| // Estimate of noise level every frame_period frames. |
| int frame_period = 8; |
| int thresh_consec_zeromv = 6; |
| int frame_counter = cm->current_frame.frame_number; |
| // Estimate is between current source and last source. |
| YV12_BUFFER_CONFIG *last_source = cpi->last_source; |
| #if CONFIG_AV1_TEMPORAL_DENOISING |
| if (cpi->oxcf.noise_sensitivity > 0) { |
| last_source = &cpi->denoiser.last_source; |
| // Tune these thresholds for different resolutions when denoising is |
| // enabled. |
| if (cm->width > 640 && cm->width <= 1920) { |
| thresh_consec_zeromv = 2; |
| } |
| } |
| #endif |
| ne->enabled = enable_noise_estimation(cpi); |
| if (!ne->enabled || frame_counter % frame_period != 0 || |
| last_source == NULL || |
| ((ne->last_w != cm->width || ne->last_h != cm->height))) { |
| #if CONFIG_AV1_TEMPORAL_DENOISING |
| if (cpi->oxcf.noise_sensitivity > 0) |
| copy_frame(&cpi->denoiser.last_source, cpi->source); |
| #endif |
| if (last_source != NULL) { |
| ne->last_w = cm->width; |
| ne->last_h = cm->height; |
| } |
| return; |
| } else { |
| unsigned int bin_size = 100; |
| unsigned int hist[MAX_VAR_HIST_BINS] = { 0 }; |
| unsigned int hist_avg[MAX_VAR_HIST_BINS]; |
| unsigned int max_bin = 0; |
| unsigned int max_bin_count = 0; |
| unsigned int bin_cnt; |
| int bsize = BLOCK_16X16; |
| // Loop over sub-sample of 16x16 blocks of frame, and for blocks that have |
| // been encoded as zero/small mv at least x consecutive frames, compute |
| // the variance to update estimate of noise in the source. |
| const uint16_t *src_y = cpi->source->y_buffer; |
| const int src_ystride = cpi->source->y_stride; |
| const uint16_t *last_src_y = last_source->y_buffer; |
| const int last_src_ystride = last_source->y_stride; |
| int mi_row, mi_col; |
| int num_low_motion = 0; |
| int frame_low_motion = 1; |
| for (mi_row = 0; mi_row < mi_params->mi_rows; mi_row += 2) { |
| for (mi_col = 0; mi_col < mi_params->mi_cols; mi_col += 2) { |
| int bl_index = |
| (mi_row >> 1) * (mi_params->mi_cols >> 1) + (mi_col >> 1); |
| if (cpi->consec_zero_mv[bl_index] > thresh_consec_zeromv) |
| num_low_motion++; |
| } |
| } |
| if (num_low_motion < |
| (((3 * (mi_params->mi_rows * mi_params->mi_cols) >> 2)) >> 3)) |
| frame_low_motion = 0; |
| for (mi_row = 0; mi_row < mi_params->mi_rows; mi_row++) { |
| for (mi_col = 0; mi_col < mi_params->mi_cols; mi_col++) { |
| // 16x16 blocks, 1/4 sample of frame. |
| if (mi_row % 8 == 0 && mi_col % 8 == 0 && |
| mi_row < mi_params->mi_rows - 3 && |
| mi_col < mi_params->mi_cols - 3) { |
| int bl_index = |
| (mi_row >> 1) * (mi_params->mi_cols >> 1) + (mi_col >> 1); |
| int bl_index1 = bl_index + 1; |
| int bl_index2 = bl_index + (mi_params->mi_cols >> 1); |
| int bl_index3 = bl_index2 + 1; |
| int consec_zeromv = |
| AOMMIN(cpi->consec_zero_mv[bl_index], |
| AOMMIN(cpi->consec_zero_mv[bl_index1], |
| AOMMIN(cpi->consec_zero_mv[bl_index2], |
| cpi->consec_zero_mv[bl_index3]))); |
| // Only consider blocks that are likely steady background. i.e, have |
| // been encoded as zero/low motion x (= thresh_consec_zeromv) frames |
| // in a row. consec_zero_mv[] defined for 8x8 blocks, so consider all |
| // 4 sub-blocks for 16x16 block. And exclude this frame if |
| // high_source_sad is true (i.e., scene/content change). |
| if (frame_low_motion && consec_zeromv > thresh_consec_zeromv && |
| !cpi->rc.high_source_sad) { |
| unsigned int sse; |
| // Compute variance between co-located blocks from current and |
| // last input frames. |
| unsigned int variance = cpi->fn_ptr[bsize].vf( |
| src_y, src_ystride, last_src_y, last_src_ystride, &sse); |
| unsigned int hist_index = variance / bin_size; |
| if (hist_index < MAX_VAR_HIST_BINS) |
| hist[hist_index]++; |
| else if (hist_index < 3 * (MAX_VAR_HIST_BINS >> 1)) |
| hist[MAX_VAR_HIST_BINS - 1]++; // Account for the tail |
| } |
| } |
| src_y += 4; |
| last_src_y += 4; |
| } |
| src_y += (src_ystride << 2) - (mi_params->mi_cols << 2); |
| last_src_y += (last_src_ystride << 2) - (mi_params->mi_cols << 2); |
| } |
| ne->last_w = cm->width; |
| ne->last_h = cm->height; |
| // Adjust histogram to account for effect that histogram flattens |
| // and shifts to zero as scene darkens. |
| if (hist[0] > 10 && (hist[MAX_VAR_HIST_BINS - 1] > hist[0] >> 2)) { |
| hist[0] = 0; |
| hist[1] >>= 2; |
| hist[2] >>= 2; |
| hist[3] >>= 2; |
| hist[4] >>= 1; |
| hist[5] >>= 1; |
| hist[6] = 3 * hist[6] >> 1; |
| hist[MAX_VAR_HIST_BINS - 1] >>= 1; |
| } |
| |
| // Average hist[] and find largest bin |
| for (bin_cnt = 0; bin_cnt < MAX_VAR_HIST_BINS; bin_cnt++) { |
| if (bin_cnt == 0) |
| hist_avg[bin_cnt] = (hist[0] + hist[1] + hist[2]) / 3; |
| else if (bin_cnt == MAX_VAR_HIST_BINS - 1) |
| hist_avg[bin_cnt] = hist[MAX_VAR_HIST_BINS - 1] >> 2; |
| else if (bin_cnt == MAX_VAR_HIST_BINS - 2) |
| hist_avg[bin_cnt] = (hist[bin_cnt - 1] + 2 * hist[bin_cnt] + |
| (hist[bin_cnt + 1] >> 1) + 2) >> |
| 2; |
| else |
| hist_avg[bin_cnt] = |
| (hist[bin_cnt - 1] + 2 * hist[bin_cnt] + hist[bin_cnt + 1] + 2) >> |
| 2; |
| |
| if (hist_avg[bin_cnt] > max_bin_count) { |
| max_bin_count = hist_avg[bin_cnt]; |
| max_bin = bin_cnt; |
| } |
| } |
| |
| // Scale by 40 to work with existing thresholds |
| ne->value = (int)((3 * ne->value + max_bin * 40) >> 2); |
| // Quickly increase VNR strength when the noise level increases suddenly. |
| if (ne->level < kMedium && ne->value > ne->adapt_thresh) { |
| ne->count = ne->num_frames_estimate; |
| } else { |
| ne->count++; |
| } |
| if (ne->count == ne->num_frames_estimate) { |
| // Reset counter and check noise level condition. |
| ne->num_frames_estimate = 30; |
| ne->count = 0; |
| ne->level = av1_noise_estimate_extract_level(ne); |
| #if CONFIG_AV1_TEMPORAL_DENOISING |
| if (cpi->oxcf.noise_sensitivity > 0) |
| av1_denoiser_set_noise_level(cpi, ne->level); |
| #endif |
| } |
| } |
| #if CONFIG_AV1_TEMPORAL_DENOISING |
| if (cpi->oxcf.noise_sensitivity > 0) |
| copy_frame(&cpi->denoiser.last_source, cpi->source); |
| #endif |
| } |
