/* * 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 #include "vp8/encoder/denoising.h" #include "vpx_mem/vpx_mem.h" #include "./vp8_rtcd.h" /* * The filter function was modified to reduce the computational complexity. * * Step 1: * Instead of applying tap coefficients for each pixel, we calculated the * pixel adjustments vs. pixel diff value ahead of time. * adjustment = filtered_value - current_raw * = (filter_coefficient * diff + 128) >> 8 * where * filter_coefficient = (255 << 8) / (256 + ((abs_diff * 330) >> 3)); * filter_coefficient += filter_coefficient / * (3 + motion_magnitude_adjustment); * filter_coefficient is clamped to 0 ~ 255. * * Step 2: * The adjustment vs. diff curve becomes flat very quick when diff increases. * This allowed us to use only several levels to approximate the curve without * changing the filtering algorithm too much. * The adjustments were further corrected by checking the motion magnitude. * The levels used are: * diff level adjustment w/o adjustment w/ * motion correction motion correction * [-255, -16] 3 -6 -7 * [-15, -8] 2 -4 -5 * [-7, -4] 1 -3 -4 * [-3, 3] 0 diff diff * [4, 7] 1 3 4 * [8, 15] 2 4 5 * [16, 255] 3 6 7 */ int vp8_denoiser_filter_neon(unsigned char *mc_running_avg_y, int mc_running_avg_y_stride, unsigned char *running_avg_y, int running_avg_y_stride, unsigned char *sig, int sig_stride, unsigned int motion_magnitude, int increase_denoising) { /* If motion_magnitude is small, making the denoiser more aggressive by * increasing the adjustment for each level, level1 adjustment is * increased, the deltas stay the same. */ int shift_inc = (increase_denoising && motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) ? 1 : 0; const uint8x16_t v_level1_adjustment = vmovq_n_u8( (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) ? 4 + shift_inc : 3); const uint8x16_t v_delta_level_1_and_2 = vdupq_n_u8(1); const uint8x16_t v_delta_level_2_and_3 = vdupq_n_u8(2); const uint8x16_t v_level1_threshold = vmovq_n_u8(4 + shift_inc); const uint8x16_t v_level2_threshold = vdupq_n_u8(8); const uint8x16_t v_level3_threshold = vdupq_n_u8(16); int64x2_t v_sum_diff_total = vdupq_n_s64(0); /* Go over lines. */ int i; for (i = 0; i < 16; ++i) { /* Load inputs. */ const uint8x16_t v_sig = vld1q_u8(sig); const uint8x16_t v_mc_running_avg_y = vld1q_u8(mc_running_avg_y); /* Calculate absolute difference and sign masks. */ const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg_y); const uint8x16_t v_diff_pos_mask = vcltq_u8(v_sig, v_mc_running_avg_y); const uint8x16_t v_diff_neg_mask = vcgtq_u8(v_sig, v_mc_running_avg_y); /* Figure out which level that put us in. */ const uint8x16_t v_level1_mask = vcleq_u8(v_level1_threshold, v_abs_diff); const uint8x16_t v_level2_mask = vcleq_u8(v_level2_threshold, v_abs_diff); const uint8x16_t v_level3_mask = vcleq_u8(v_level3_threshold, v_abs_diff); /* Calculate absolute adjustments for level 1, 2 and 3. */ const uint8x16_t v_level2_adjustment = vandq_u8(v_level2_mask, v_delta_level_1_and_2); const uint8x16_t v_level3_adjustment = vandq_u8(v_level3_mask, v_delta_level_2_and_3); const uint8x16_t v_level1and2_adjustment = vaddq_u8(v_level1_adjustment, v_level2_adjustment); const uint8x16_t v_level1and2and3_adjustment = vaddq_u8( v_level1and2_adjustment, v_level3_adjustment); /* Figure adjustment absolute value by selecting between the absolute * difference if in level0 or the value for level 1, 2 and 3. */ const uint8x16_t v_abs_adjustment = vbslq_u8(v_level1_mask, v_level1and2and3_adjustment, v_abs_diff); /* Calculate positive and negative adjustments. Apply them to the signal * and accumulate them. Adjustments are less than eight and the maximum * sum of them (7 * 16) can fit in a signed char. */ const uint8x16_t v_pos_adjustment = vandq_u8(v_diff_pos_mask, v_abs_adjustment); const uint8x16_t v_neg_adjustment = vandq_u8(v_diff_neg_mask, v_abs_adjustment); uint8x16_t v_running_avg_y = vqaddq_u8(v_sig, v_pos_adjustment); v_running_avg_y = vqsubq_u8(v_running_avg_y, v_neg_adjustment); /* Store results. */ vst1q_u8(running_avg_y, v_running_avg_y); /* Sum all the accumulators to have the sum of all pixel differences * for this macroblock. */ { const int8x16_t v_sum_diff = vqsubq_s8(vreinterpretq_s8_u8(v_pos_adjustment), vreinterpretq_s8_u8(v_neg_adjustment)); const int16x8_t fe_dc_ba_98_76_54_32_10 = vpaddlq_s8(v_sum_diff); const int32x4_t fedc_ba98_7654_3210 = vpaddlq_s16(fe_dc_ba_98_76_54_32_10); const int64x2_t fedcba98_76543210 = vpaddlq_s32(fedc_ba98_7654_3210); v_sum_diff_total = vqaddq_s64(v_sum_diff_total, fedcba98_76543210); } /* Update pointers for next iteration. */ sig += sig_stride; mc_running_avg_y += mc_running_avg_y_stride; running_avg_y += running_avg_y_stride; } /* Too much adjustments => copy block. */ { const int64x1_t x = vqadd_s64(vget_high_s64(v_sum_diff_total), vget_low_s64(v_sum_diff_total)); const int s0 = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0); int sum_diff_thresh = SUM_DIFF_THRESHOLD; if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH; if (s0 > sum_diff_thresh) return COPY_BLOCK; } /* Tell above level that block was filtered. */ running_avg_y -= running_avg_y_stride * 16; sig -= sig_stride * 16; vp8_copy_mem16x16(running_avg_y, running_avg_y_stride, sig, sig_stride); return FILTER_BLOCK; }