Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/adaptive_fir_filter.cc

+/*
+ *  Copyright (c) 2017 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 "webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h"
+
+#include "webrtc/typedefs.h"
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#include <emmintrin.h>
+#endif
+#include <algorithm>
+#include <functional>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/audio_processing/aec3/fft_data.h"
+
+namespace webrtc {
+
+namespace {
+
+// Constrains the a partiton of the frequency domain filter to be limited in
+// time via setting the relevant time-domain coefficients to zero.
+void Constrain(const Aec3Fft& fft, FftData* H) {
+  std::array<float, kFftLength> h;
+  fft.Ifft(*H, &h);
+  constexpr float kScale = 1.0f / kFftLengthBy2;
+  std::for_each(h.begin(), h.begin() + kFftLengthBy2,
+                [kScale](float& a) { a *= kScale; });
+  std::fill(h.begin() + kFftLengthBy2, h.end(), 0.f);
+  fft.Fft(&h, H);
+}
+
+// Computes and stores the frequency response of the filter.
+void UpdateFrequencyResponse(
+    rtc::ArrayView<const FftData> H,
+    std::vector<std::array<float, kFftLengthBy2Plus1>>* H2) {
+  for (size_t k = 0; k < H.size(); ++k) {
+    std::transform(H[k].re.begin(), H[k].re.end(), H[k].im.begin(),
+                   (*H2)[k].begin(),
+                   [](float a, float b) { return a * a + b * b; });
+  }
+}
+
+// Computes and stores the echo return loss estimate of the filter, which is the
+// sum of the partition frequency responses.
+void UpdateErlEstimator(
+    const std::vector<std::array<float, kFftLengthBy2Plus1>>& H2,
+    std::array<float, kFftLengthBy2Plus1>* erl) {
+  erl->fill(0.f);
+  for (auto& H2_j : H2) {
+    std::transform(H2_j.begin(), H2_j.end(), erl->begin(), erl->begin(),
+                   std::plus<float>());
+  }
+}
+
+// Resets the filter.
+void ResetFilter(rtc::ArrayView<FftData> H) {
+  for (auto& H_j : H) {
+    H_j.Clear();
+  }
+}
+
+}  // namespace
+
+namespace aec3 {
+
+// Adapts the filter partitions as H(t+1)=H(t)+G(t)*conj(X(t)).
+void AdaptPartitions(const FftBuffer& X_buffer,
+                     const FftData& G,
+                     rtc::ArrayView<FftData> H) {
+  rtc::ArrayView<const FftData> X_buffer_data = X_buffer.Buffer();
+  size_t index = X_buffer.Position();
+  for (auto& H_j : H) {
+    const FftData& X = X_buffer_data[index];
+    for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
+      H_j.re[k] += X.re[k] * G.re[k] + X.im[k] * G.im[k];
+      H_j.im[k] += X.re[k] * G.im[k] - X.im[k] * G.re[k];
+    }
+
+    index = index < (X_buffer_data.size() - 1) ? index + 1 : 0;
+  }
+}
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+// Adapts the filter partitions. (SSE2 variant)
+void AdaptPartitions_SSE2(const FftBuffer& X_buffer,
+                          const FftData& G,
+                          rtc::ArrayView<FftData> H) {
+  rtc::ArrayView<const FftData> X_buffer_data = X_buffer.Buffer();
+  const int lim1 =
+      std::min(X_buffer_data.size() - X_buffer.Position(), H.size());
+  const int lim2 = H.size();
+  constexpr int kNumFourBinBands = kFftLengthBy2 / 4;
+  FftData* H_j;
+  const FftData* X;
+  int limit;
+  int j;
+  for (int k = 0, n = 0; n < kNumFourBinBands; ++n, k += 4) {
+    const __m128 G_re = _mm_loadu_ps(&G.re[k]);
+    const __m128 G_im = _mm_loadu_ps(&G.im[k]);
+
+    H_j = &H[0];
+    X = &X_buffer_data[X_buffer.Position()];
+    limit = lim1;
+    j = 0;
+    do {
+      for (; j < limit; ++j, ++H_j, ++X) {
+        const __m128 X_re = _mm_loadu_ps(&X->re[k]);
+        const __m128 X_im = _mm_loadu_ps(&X->im[k]);
+        const __m128 H_re = _mm_loadu_ps(&H_j->re[k]);
+        const __m128 H_im = _mm_loadu_ps(&H_j->im[k]);
+        const __m128 a = _mm_mul_ps(X_re, G_re);
+        const __m128 b = _mm_mul_ps(X_im, G_im);
+        const __m128 c = _mm_mul_ps(X_re, G_im);
+        const __m128 d = _mm_mul_ps(X_im, G_re);
+        const __m128 e = _mm_add_ps(a, b);
+        const __m128 f = _mm_sub_ps(c, d);
+        const __m128 g = _mm_add_ps(H_re, e);
+        const __m128 h = _mm_add_ps(H_im, f);
+        _mm_storeu_ps(&H_j->re[k], g);
+        _mm_storeu_ps(&H_j->im[k], h);
+      }
+
+      X = &X_buffer_data[0];
+      limit = lim2;
+    } while (j < lim2);
+  }
+
+  H_j = &H[0];
+  X = &X_buffer_data[X_buffer.Position()];
+  limit = lim1;
+  j = 0;
+  do {
+    for (; j < limit; ++j, ++H_j, ++X) {
+      H_j->re[kFftLengthBy2] += X->re[kFftLengthBy2] * G.re[kFftLengthBy2] +
+                                X->im[kFftLengthBy2] * G.im[kFftLengthBy2];
+      H_j->im[kFftLengthBy2] += X->re[kFftLengthBy2] * G.im[kFftLengthBy2] -
+                                X->im[kFftLengthBy2] * G.re[kFftLengthBy2];
+    }
+
+    X = &X_buffer_data[0];
+    limit = lim2;
+  } while (j < lim2);
+}
+#endif
+
+// Produces the filter output.
+void ApplyFilter(const FftBuffer& X_buffer,
+                 rtc::ArrayView<const FftData> H,
+                 FftData* S) {
+  S->re.fill(0.f);
+  S->im.fill(0.f);
+
+  rtc::ArrayView<const FftData> X_buffer_data = X_buffer.Buffer();
+  size_t index = X_buffer.Position();
+  for (auto& H_j : H) {
+    const FftData& X = X_buffer_data[index];
+    for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
+      S->re[k] += X.re[k] * H_j.re[k] - X.im[k] * H_j.im[k];
+      S->im[k] += X.re[k] * H_j.im[k] + X.im[k] * H_j.re[k];
+    }
+    index = index < (X_buffer_data.size() - 1) ? index + 1 : 0;
+  }
+}
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+// Produces the filter output (SSE2 variant).
+void ApplyFilter_SSE2(const FftBuffer& X_buffer,
+                      rtc::ArrayView<const FftData> H,
+                      FftData* S) {
+  S->re.fill(0.f);
+  S->im.fill(0.f);
+
+  rtc::ArrayView<const FftData> X_buffer_data = X_buffer.Buffer();
+  const int lim1 =
+      std::min(X_buffer_data.size() - X_buffer.Position(), H.size());
+  const int lim2 = H.size();
+  constexpr int kNumFourBinBands = kFftLengthBy2 / 4;
+  const FftData* H_j = &H[0];
+  const FftData* X = &X_buffer_data[X_buffer.Position()];
+
+  int j = 0;
+  int limit = lim1;
+  do {
+    for (; j < limit; ++j, ++H_j, ++X) {
+      for (int k = 0, n = 0; n < kNumFourBinBands; ++n, k += 4) {
+        const __m128 X_re = _mm_loadu_ps(&X->re[k]);
+        const __m128 X_im = _mm_loadu_ps(&X->im[k]);
+        const __m128 H_re = _mm_loadu_ps(&H_j->re[k]);
+        const __m128 H_im = _mm_loadu_ps(&H_j->im[k]);
+        const __m128 S_re = _mm_loadu_ps(&S->re[k]);
+        const __m128 S_im = _mm_loadu_ps(&S->im[k]);
+        const __m128 a = _mm_mul_ps(X_re, H_re);
+        const __m128 b = _mm_mul_ps(X_im, H_im);
+        const __m128 c = _mm_mul_ps(X_re, H_im);
+        const __m128 d = _mm_mul_ps(X_im, H_re);
+        const __m128 e = _mm_sub_ps(a, b);
+        const __m128 f = _mm_add_ps(c, d);
+        const __m128 g = _mm_add_ps(S_re, e);
+        const __m128 h = _mm_add_ps(S_im, f);
+        _mm_storeu_ps(&S->re[k], g);
+        _mm_storeu_ps(&S->im[k], h);
+      }
+    }
+    limit = lim2;
+    X = &X_buffer_data[0];
+  } while (j < lim2);
+
+  H_j = &H[0];
+  X = &X_buffer_data[X_buffer.Position()];
+  j = 0;
+  limit = lim1;
+  do {
+    for (; j < limit; ++j, ++H_j, ++X) {
+      S->re[kFftLengthBy2] += X->re[kFftLengthBy2] * H_j->re[kFftLengthBy2] -
+                              X->im[kFftLengthBy2] * H_j->im[kFftLengthBy2];
+      S->im[kFftLengthBy2] += X->re[kFftLengthBy2] * H_j->im[kFftLengthBy2] +
+                              X->im[kFftLengthBy2] * H_j->re[kFftLengthBy2];
+    }
+    limit = lim2;
+    X = &X_buffer_data[0];
+  } while (j < lim2);
+}
+#endif
+
+}  // namespace aec3
+
+AdaptiveFirFilter::AdaptiveFirFilter(size_t size_partitions,
+                                     bool use_filter_statistics,
+                                     Aec3Optimization optimization,
+                                     ApmDataDumper* data_dumper)
+    : data_dumper_(data_dumper),
+      optimization_(optimization),
+      H_(size_partitions) {
+  RTC_DCHECK(data_dumper_);
+  ResetFilter(H_);
+
+  if (use_filter_statistics) {
+    H2_.reset(new std::vector<std::array<float, kFftLengthBy2Plus1>>(
+        size_partitions, std::array<float, kFftLengthBy2Plus1>()));
+    for (auto H2_k : *H2_) {
+      H2_k.fill(0.f);
+    }
+
+    erl_.reset(new std::array<float, kFftLengthBy2Plus1>());
+    erl_->fill(0.f);
+  }
+}
+
+AdaptiveFirFilter::~AdaptiveFirFilter() = default;
+
+void AdaptiveFirFilter::HandleEchoPathChange() {
+  ResetFilter(H_);
+  if (H2_) {
+    for (auto H2_k : *H2_) {
+      H2_k.fill(0.f);
+    }
+    RTC_DCHECK(erl_);
+    erl_->fill(0.f);
+  }
+}
+
+void AdaptiveFirFilter::Filter(const FftBuffer& X_buffer, FftData* S) const {
+  RTC_DCHECK(S);
+  switch (optimization_) {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+    case Aec3Optimization::kSse2:
+      aec3::ApplyFilter_SSE2(X_buffer, H_, S);
+      break;
+#endif
+    default:
+      aec3::ApplyFilter(X_buffer, H_, S);
+  }
+}
+
+void AdaptiveFirFilter::Adapt(const FftBuffer& X_buffer, const FftData& G) {
+  // Adapt the filter.
+  switch (optimization_) {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+    case Aec3Optimization::kSse2:
+      aec3::AdaptPartitions_SSE2(X_buffer, G, H_);
+      break;
+#endif
+    default:
+      aec3::AdaptPartitions(X_buffer, G, H_);
+  }
+
+  // Constrain the filter partitions in a cyclic manner.
+  Constrain(fft_, &H_[partition_to_constrain_]);
+  partition_to_constrain_ = partition_to_constrain_ < (H_.size() - 1)
+                                ? partition_to_constrain_ + 1
+                                : 0;
+
+  // Optionally update the frequency response and echo return loss for the
+  // filter.
+  if (H2_) {
+    RTC_DCHECK(erl_);
+    UpdateFrequencyResponse(H_, H2_.get());
+    UpdateErlEstimator(*H2_, erl_.get());
+  }
+}
+
+}  // namespace webrtc