Standalone denoiser (off by default).

webrtc/modules/video_processing/util/denoiser_filter_neon.cc

Index: webrtc/modules/video_processing/util/denoiser_filter_neon.cc
diff --git a/webrtc/modules/video_processing/util/denoiser_filter_neon.cc b/webrtc/modules/video_processing/util/denoiser_filter_neon.cc
new file mode 100644
index 0000000000000000000000000000000000000000..67d420cda723a27bb8bcdc72dbae3ad701bc8a03
--- /dev/null
+++ b/webrtc/modules/video_processing/util/denoiser_filter_neon.cc
@@ -0,0 +1,284 @@
+/*
+ *  Copyright (c) 2015 The WebRTC 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 <arm_neon.h>
+
+#include "webrtc/modules/video_processing/util/denoiser_filter_neon.h"
+
+namespace webrtc {
+
+static int HorizontalAddS16x8(const int16x8_t v_16x8) {
+  const int32x4_t a = vpaddlq_s16(v_16x8);
+  const int64x2_t b = vpaddlq_s32(a);
+  const int32x2_t c = vadd_s32(vreinterpret_s32_s64(vget_low_s64(b)),
+                               vreinterpret_s32_s64(vget_high_s64(b)));
+  return vget_lane_s32(c, 0);
+}
+
+static int HorizontalAddS32x4(const int32x4_t v_32x4) {
+  const int64x2_t b = vpaddlq_s32(v_32x4);
+  const int32x2_t c = vadd_s32(vreinterpret_s32_s64(vget_low_s64(b)),
+                               vreinterpret_s32_s64(vget_high_s64(b)));
+  return vget_lane_s32(c, 0);
+}
+
+static void VarianceNeonW8(const uint8_t* a,
+                           int a_stride,
+                           const uint8_t* b,
+                           int b_stride,
+                           int w,
+                           int h,
+                           uint32_t* sse,
+                           int64_t* sum) {
+  int16x8_t v_sum = vdupq_n_s16(0);
+  int32x4_t v_sse_lo = vdupq_n_s32(0);
+  int32x4_t v_sse_hi = vdupq_n_s32(0);
+
+  for (int i = 0; i < h; ++i) {
+    for (int j = 0; j < w; j += 8) {
+      const uint8x8_t v_a = vld1_u8(&a[j]);
+      const uint8x8_t v_b = vld1_u8(&b[j]);
+      const uint16x8_t v_diff = vsubl_u8(v_a, v_b);
+      const int16x8_t sv_diff = vreinterpretq_s16_u16(v_diff);
+      v_sum = vaddq_s16(v_sum, sv_diff);
+      v_sse_lo =
+          vmlal_s16(v_sse_lo, vget_low_s16(sv_diff), vget_low_s16(sv_diff));
+      v_sse_hi =
+          vmlal_s16(v_sse_hi, vget_high_s16(sv_diff), vget_high_s16(sv_diff));
+    }
+    a += a_stride;
+    b += b_stride;
+  }
+
+  *sum = HorizontalAddS16x8(v_sum);
+  *sse = static_cast<uint32_t>(
+      HorizontalAddS32x4(vaddq_s32(v_sse_lo, v_sse_hi)));
+}
+
+void DenoiserFilterNEON::CopyMem16x16(const uint8_t* src,
+                                      int src_stride,
+                                      uint8_t* dst,
+                                      int dst_stride) {
+  uint8x16_t qtmp;
+  for (int r = 0; r < 16; r++) {
+    qtmp = vld1q_u8(src);
+    vst1q_u8(dst, qtmp);
+    src += src_stride;
+    dst += dst_stride;
+  }
+}
+
+void DenoiserFilterNEON::CopyMem8x8(const uint8_t* src,
+                                    int src_stride,
+                                    uint8_t* dst,
+                                    int dst_stride) {
+  uint8x8_t vtmp;
+
+  for (int r = 0; r < 8; r++) {
+    vtmp = vld1_u8(src);
+    vst1_u8(dst, vtmp);
+    src += src_stride;
+    dst += dst_stride;
+  }
+}
+
+uint32_t DenoiserFilterNEON::Variance16x8(const uint8_t* a,
+                                          int a_stride,
+                                          const uint8_t* b,
+                                          int b_stride,
+                                          uint32_t* sse) {
+  int64_t sum = 0;
+  VarianceNeonW8(a, a_stride << 1, b, b_stride << 1, 16, 8, sse, &sum);
+  return *sse - ((sum * sum) >> 7);
+}
+
+DenoiserDecision DenoiserFilterNEON::MbDenoise(uint8_t* mc_running_avg_y,
+                                               int mc_running_avg_y_stride,
+                                               uint8_t* running_avg_y,
+                                               int running_avg_y_stride,
+                                               const uint8_t* sig,
+                                               int sig_stride,
+                                               uint8_t 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 <= kMotionMagnitudeThreshold)
+          ? 1
+          : 0;
+  const uint8x16_t v_level1_adjustment = vmovq_n_u8(
+      (motion_magnitude <= kMotionMagnitudeThreshold) ? 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.
+  for (int r = 0; r < 16; ++r) {
+    // 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.
+  {
+    int64x1_t x = vqadd_s64(vget_high_s64(v_sum_diff_total),
+                            vget_low_s64(v_sum_diff_total));
+    int sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
+    int sum_diff_thresh = kSumDiffThreshold;
+
+    if (increase_denoising)
+      sum_diff_thresh = kSumDiffThresholdHigh;
+    if (sum_diff > sum_diff_thresh) {
+      // Before returning to copy the block (i.e., apply no denoising),
+      // checK if we can still apply some (weaker) temporal filtering to
+      // this block, that would otherwise not be denoised at all. Simplest
+      // is to apply an additional adjustment to running_avg_y to bring it
+      // closer to sig. The adjustment is capped by a maximum delta, and
+      // chosen such that in most cases the resulting sum_diff will be
+      // within the accceptable range given by sum_diff_thresh.
+
+      // The delta is set by the excess of absolute pixel diff over the
+      // threshold.
+      int delta = ((sum_diff - sum_diff_thresh) >> 8) + 1;
+      // Only apply the adjustment for max delta up to 3.
+      if (delta < 4) {
+        const uint8x16_t k_delta = vmovq_n_u8(delta);
+        sig -= sig_stride * 16;
+        mc_running_avg_y -= mc_running_avg_y_stride * 16;
+        running_avg_y -= running_avg_y_stride * 16;
+        for (int r = 0; r < 16; ++r) {
+          uint8x16_t v_running_avg_y = vld1q_u8(running_avg_y);
+          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);
+          // Clamp absolute difference to delta to get the adjustment.
+          const uint8x16_t v_abs_adjustment = vminq_u8(v_abs_diff, (k_delta));
+
+          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);
+
+          v_running_avg_y = vqsubq_u8(v_running_avg_y, v_pos_adjustment);
+          v_running_avg_y = vqaddq_u8(v_running_avg_y, v_neg_adjustment);
+
+          // Store results.
+          vst1q_u8(running_avg_y, v_running_avg_y);
+
+          {
+            const int8x16_t v_sum_diff =
+                vqsubq_s8(vreinterpretq_s8_u8(v_neg_adjustment),
+                          vreinterpretq_s8_u8(v_pos_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;
+        }
+        {
+          // Update the sum of all pixel differences of this MB.
+          x = vqadd_s64(vget_high_s64(v_sum_diff_total),
+                        vget_low_s64(v_sum_diff_total));
+          sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
+
+          if (sum_diff > sum_diff_thresh) {
+            return COPY_BLOCK;
+          }
+        }
+      } else {
+        return COPY_BLOCK;
+      }
+    }
+  }
+
+  // Tell above level that block was filtered.
+  running_avg_y -= running_avg_y_stride * 16;
+  sig -= sig_stride * 16;
+
+  return FILTER_BLOCK;
+}
+
+}  // namespace webrtc