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 <arm_neon.h> 12 13 #include "vp8/encoder/denoising.h" 14 #include "vpx_mem/vpx_mem.h" 15 #include "./vp8_rtcd.h" 16 17 /* 18 * The filter function was modified to reduce the computational complexity. 19 * 20 * Step 1: 21 * Instead of applying tap coefficients for each pixel, we calculated the 22 * pixel adjustments vs. pixel diff value ahead of time. 23 * adjustment = filtered_value - current_raw 24 * = (filter_coefficient * diff + 128) >> 8 25 * where 26 * filter_coefficient = (255 << 8) / (256 + ((abs_diff * 330) >> 3)); 27 * filter_coefficient += filter_coefficient / 28 * (3 + motion_magnitude_adjustment); 29 * filter_coefficient is clamped to 0 ~ 255. 30 * 31 * Step 2: 32 * The adjustment vs. diff curve becomes flat very quick when diff increases. 33 * This allowed us to use only several levels to approximate the curve without 34 * changing the filtering algorithm too much. 35 * The adjustments were further corrected by checking the motion magnitude. 36 * The levels used are: 37 * diff level adjustment w/o adjustment w/ 38 * motion correction motion correction 39 * [-255, -16] 3 -6 -7 40 * [-15, -8] 2 -4 -5 41 * [-7, -4] 1 -3 -4 42 * [-3, 3] 0 diff diff 43 * [4, 7] 1 3 4 44 * [8, 15] 2 4 5 45 * [16, 255] 3 6 7 46 */ 47 48 int vp8_denoiser_filter_neon(YV12_BUFFER_CONFIG *mc_running_avg, 49 YV12_BUFFER_CONFIG *running_avg, 50 MACROBLOCK *signal, unsigned int motion_magnitude, 51 int y_offset, int uv_offset) { 52 /* If motion_magnitude is small, making the denoiser more aggressive by 53 * increasing the adjustment for each level, level1 adjustment is 54 * increased, the deltas stay the same. 55 */ 56 const uint8x16_t v_level1_adjustment = vdupq_n_u8( 57 (motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) ? 4 : 3); 58 const uint8x16_t v_delta_level_1_and_2 = vdupq_n_u8(1); 59 const uint8x16_t v_delta_level_2_and_3 = vdupq_n_u8(2); 60 const uint8x16_t v_level1_threshold = vdupq_n_u8(4); 61 const uint8x16_t v_level2_threshold = vdupq_n_u8(8); 62 const uint8x16_t v_level3_threshold = vdupq_n_u8(16); 63 64 /* Local variables for array pointers and strides. */ 65 unsigned char *sig = signal->thismb; 66 int sig_stride = 16; 67 unsigned char *mc_running_avg_y = mc_running_avg->y_buffer + y_offset; 68 int mc_running_avg_y_stride = mc_running_avg->y_stride; 69 unsigned char *running_avg_y = running_avg->y_buffer + y_offset; 70 int running_avg_y_stride = running_avg->y_stride; 71 72 /* Go over lines. */ 73 int i; 74 int sum_diff = 0; 75 for (i = 0; i < 16; ++i) { 76 int8x16_t v_sum_diff = vdupq_n_s8(0); 77 uint8x16_t v_running_avg_y; 78 79 /* Load inputs. */ 80 const uint8x16_t v_sig = vld1q_u8(sig); 81 const uint8x16_t v_mc_running_avg_y = vld1q_u8(mc_running_avg_y); 82 83 /* Calculate absolute difference and sign masks. */ 84 const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg_y); 85 const uint8x16_t v_diff_pos_mask = vcltq_u8(v_sig, v_mc_running_avg_y); 86 const uint8x16_t v_diff_neg_mask = vcgtq_u8(v_sig, v_mc_running_avg_y); 87 88 /* Figure out which level that put us in. */ 89 const uint8x16_t v_level1_mask = vcleq_u8(v_level1_threshold, 90 v_abs_diff); 91 const uint8x16_t v_level2_mask = vcleq_u8(v_level2_threshold, 92 v_abs_diff); 93 const uint8x16_t v_level3_mask = vcleq_u8(v_level3_threshold, 94 v_abs_diff); 95 96 /* Calculate absolute adjustments for level 1, 2 and 3. */ 97 const uint8x16_t v_level2_adjustment = vandq_u8(v_level2_mask, 98 v_delta_level_1_and_2); 99 const uint8x16_t v_level3_adjustment = vandq_u8(v_level3_mask, 100 v_delta_level_2_and_3); 101 const uint8x16_t v_level1and2_adjustment = vaddq_u8(v_level1_adjustment, 102 v_level2_adjustment); 103 const uint8x16_t v_level1and2and3_adjustment = vaddq_u8( 104 v_level1and2_adjustment, v_level3_adjustment); 105 106 /* Figure adjustment absolute value by selecting between the absolute 107 * difference if in level0 or the value for level 1, 2 and 3. 108 */ 109 const uint8x16_t v_abs_adjustment = vbslq_u8(v_level1_mask, 110 v_level1and2and3_adjustment, v_abs_diff); 111 112 /* Calculate positive and negative adjustments. Apply them to the signal 113 * and accumulate them. Adjustments are less than eight and the maximum 114 * sum of them (7 * 16) can fit in a signed char. 115 */ 116 const uint8x16_t v_pos_adjustment = vandq_u8(v_diff_pos_mask, 117 v_abs_adjustment); 118 const uint8x16_t v_neg_adjustment = vandq_u8(v_diff_neg_mask, 119 v_abs_adjustment); 120 v_running_avg_y = vqaddq_u8(v_sig, v_pos_adjustment); 121 v_running_avg_y = vqsubq_u8(v_running_avg_y, v_neg_adjustment); 122 v_sum_diff = vqaddq_s8(v_sum_diff, 123 vreinterpretq_s8_u8(v_pos_adjustment)); 124 v_sum_diff = vqsubq_s8(v_sum_diff, 125 vreinterpretq_s8_u8(v_neg_adjustment)); 126 127 /* Store results. */ 128 vst1q_u8(running_avg_y, v_running_avg_y); 129 130 /* Sum all the accumulators to have the sum of all pixel differences 131 * for this macroblock. 132 */ 133 { 134 int s0 = vgetq_lane_s8(v_sum_diff, 0) + 135 vgetq_lane_s8(v_sum_diff, 1) + 136 vgetq_lane_s8(v_sum_diff, 2) + 137 vgetq_lane_s8(v_sum_diff, 3); 138 int s1 = vgetq_lane_s8(v_sum_diff, 4) + 139 vgetq_lane_s8(v_sum_diff, 5) + 140 vgetq_lane_s8(v_sum_diff, 6) + 141 vgetq_lane_s8(v_sum_diff, 7); 142 int s2 = vgetq_lane_s8(v_sum_diff, 8) + 143 vgetq_lane_s8(v_sum_diff, 9) + 144 vgetq_lane_s8(v_sum_diff, 10) + 145 vgetq_lane_s8(v_sum_diff, 11); 146 int s3 = vgetq_lane_s8(v_sum_diff, 12) + 147 vgetq_lane_s8(v_sum_diff, 13) + 148 vgetq_lane_s8(v_sum_diff, 14) + 149 vgetq_lane_s8(v_sum_diff, 15); 150 sum_diff += s0 + s1+ s2 + s3; 151 } 152 153 /* Update pointers for next iteration. */ 154 sig += sig_stride; 155 mc_running_avg_y += mc_running_avg_y_stride; 156 running_avg_y += running_avg_y_stride; 157 } 158 159 /* Too much adjustments => copy block. */ 160 if (abs(sum_diff) > SUM_DIFF_THRESHOLD) 161 return COPY_BLOCK; 162 163 /* Tell above level that block was filtered. */ 164 vp8_copy_mem16x16(running_avg->y_buffer + y_offset, running_avg_y_stride, 165 signal->thismb, sig_stride); 166 return FILTER_BLOCK; 167 } 168
