Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/suppression_filter_unittest.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/suppression_filter.h"
+
+#include <math.h>
+#include <algorithm>
+#include <numeric>
+
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace {
+
+constexpr float kPi = 3.141592f;
+
+void ProduceSinusoid(int sample_rate_hz,
+                     float sinusoidal_frequency_hz,
+                     size_t* sample_counter,
+                     rtc::ArrayView<float> x) {
+  // Produce a sinusoid of the specified frequency.
+  for (size_t k = *sample_counter, j = 0; k < (*sample_counter + kBlockSize);
+       ++k, ++j) {
+    x[j] =
+        32767.f * sin(2.f * kPi * sinusoidal_frequency_hz * k / sample_rate_hz);
+  }
+  *sample_counter = *sample_counter + kBlockSize;
+}
+
+}  // namespace
+
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+
+// Verifies the check for null suppressor output.
+TEST(SuppressionFilter, NullOutput) {
+  FftData cn;
+  FftData cn_high_bands;
+  std::array<float, kFftLengthBy2Plus1> gain;
+
+  EXPECT_DEATH(
+      SuppressionFilter(16000).ApplyGain(cn, cn_high_bands, gain, nullptr), "");
+}
+
+// Verifies the check for allowed sample rate.
+TEST(SuppressionFilter, ProperSampleRate) {
+  EXPECT_DEATH(SuppressionFilter(16001), "");
+}
+
+#endif
+
+// Verifies that no comfort noise is added when the gain is 1.
+TEST(SuppressionFilter, ComfortNoiseInUnityGain) {
+  SuppressionFilter filter(48000);
+  FftData cn;
+  FftData cn_high_bands;
+  std::array<float, kFftLengthBy2Plus1> gain;
+
+  gain.fill(1.f);
+  cn.re.fill(1.f);
+  cn.im.fill(1.f);
+  cn_high_bands.re.fill(1.f);
+  cn_high_bands.im.fill(1.f);
+
+  std::vector<std::vector<float>> e(3, std::vector<float>(kBlockSize, 0.f));
+  std::vector<std::vector<float>> e_ref = e;
+  filter.ApplyGain(cn, cn_high_bands, gain, &e);
+
+  for (size_t k = 0; k < e.size(); ++k) {
+    EXPECT_EQ(e_ref[k], e[k]);
+  }
+}
+
+// Verifies that the suppressor is able to suppress a signal.
+TEST(SuppressionFilter, SignalSuppression) {
+  SuppressionFilter filter(48000);
+  FftData cn;
+  FftData cn_high_bands;
+  std::array<float, kFftLengthBy2Plus1> gain;
+  std::vector<std::vector<float>> e(3, std::vector<float>(kBlockSize, 0.f));
+
+  gain.fill(1.f);
+  std::for_each(gain.begin() + 10, gain.end(), [](float& a) { a = 0.f; });
+
+  cn.re.fill(0.f);
+  cn.im.fill(0.f);
+  cn_high_bands.re.fill(0.f);
+  cn_high_bands.im.fill(0.f);
+
+  size_t sample_counter = 0;
+
+  float e0_input = 0.f;
+  float e0_output = 0.f;
+  for (size_t k = 0; k < 100; ++k) {
+    ProduceSinusoid(16000, 16000 * 40 / kFftLengthBy2 / 2, &sample_counter,
+                    e[0]);
+    e0_input =
+        std::inner_product(e[0].begin(), e[0].end(), e[0].begin(), e0_input);
+    filter.ApplyGain(cn, cn_high_bands, gain, &e);
+    e0_output =
+        std::inner_product(e[0].begin(), e[0].end(), e[0].begin(), e0_output);
+  }
+
+  EXPECT_LT(e0_output, e0_input / 1000.f);
+}
+
+// Verifies that the suppressor is able to pass through a desired signal while
+// applying suppressing for some frequencies.
+TEST(SuppressionFilter, SignalTransparency) {
+  SuppressionFilter filter(48000);
+  FftData cn;
+  FftData cn_high_bands;
+  std::array<float, kFftLengthBy2Plus1> gain;
+  std::vector<std::vector<float>> e(3, std::vector<float>(kBlockSize, 0.f));
+
+  gain.fill(1.f);
+  std::for_each(gain.begin() + 30, gain.end(), [](float& a) { a = 0.f; });
+
+  cn.re.fill(0.f);
+  cn.im.fill(0.f);
+  cn_high_bands.re.fill(0.f);
+  cn_high_bands.im.fill(0.f);
+
+  size_t sample_counter = 0;
+
+  float e0_input = 0.f;
+  float e0_output = 0.f;
+  for (size_t k = 0; k < 100; ++k) {
+    ProduceSinusoid(16000, 16000 * 10 / kFftLengthBy2 / 2, &sample_counter,
+                    e[0]);
+    e0_input =
+        std::inner_product(e[0].begin(), e[0].end(), e[0].begin(), e0_input);
+    filter.ApplyGain(cn, cn_high_bands, gain, &e);
+    e0_output =
+        std::inner_product(e[0].begin(), e[0].end(), e[0].begin(), e0_output);
+  }
+
+  EXPECT_LT(0.9f * e0_input, e0_output);
+}
+
+// Verifies that the suppressor delay.
+TEST(SuppressionFilter, Delay) {
+  SuppressionFilter filter(48000);
+  FftData cn;
+  FftData cn_high_bands;
+  std::array<float, kFftLengthBy2Plus1> gain;
+  std::vector<std::vector<float>> e(3, std::vector<float>(kBlockSize, 0.f));
+
+  gain.fill(1.f);
+
+  cn.re.fill(0.f);
+  cn.im.fill(0.f);
+  cn_high_bands.re.fill(0.f);
+  cn_high_bands.im.fill(0.f);
+
+  for (size_t k = 0; k < 100; ++k) {
+    for (size_t j = 0; j < 3; ++j) {
+      for (size_t i = 0; i < kBlockSize; ++i) {
+        e[j][i] = k * kBlockSize + i;
+      }
+    }
+
+    filter.ApplyGain(cn, cn_high_bands, gain, &e);
+    if (k > 2) {
+      for (size_t j = 0; j < 2; ++j) {
+        for (size_t i = 0; i < kBlockSize; ++i) {
+          EXPECT_NEAR(k * kBlockSize + i - kBlockSize, e[j][i], 0.01);
+        }
+      }
+    }
+  }
+}
+
+}  // namespace webrtc