Transparency increasing tuning for AEC3

webrtc/modules/audio_processing/aec3/aec_state_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.
  */
 
@@ skipping 96 matching lines @@
   E2_main.fill(1.f * 10000.f * 10000.f);
   Y2.fill(10.f * E2_main[0]);
   for (size_t k = 0; k < 1000; ++k) {
     state.Update(converged_filter_frequency_response, rtc::Optional<size_t>(2),
                  render_buffer, E2_main, Y2, x[0], false);
   }
   ASSERT_TRUE(state.UsableLinearEstimate());
   {
     const auto& erle = state.Erle();
     EXPECT_EQ(erle[0], erle[1]);
-    for (size_t k = 1; k < erle.size() - 1; ++k) {
+    constexpr size_t kLowFrequencyLimit = 32;
+    for (size_t k = 1; k < kLowFrequencyLimit; ++k) {
       EXPECT_NEAR(k % 2 == 0 ? 8.f : 1.f, erle[k], 0.1);
     }
+    for (size_t k = kLowFrequencyLimit; k < erle.size() - 1; ++k) {
+      EXPECT_NEAR(k % 2 == 0 ? 1.5f : 1.f, erle[k], 0.1);
+    }
     EXPECT_EQ(erle[erle.size() - 2], erle[erle.size() - 1]);
   }
 
   E2_main.fill(1.f * 10000.f * 10000.f);
   Y2.fill(5.f * E2_main[0]);
   for (size_t k = 0; k < 1000; ++k) {
     state.Update(converged_filter_frequency_response, rtc::Optional<size_t>(2),
                  render_buffer, E2_main, Y2, x[0], false);
   }
 
   ASSERT_TRUE(state.UsableLinearEstimate());
   {
     const auto& erle = state.Erle();
     EXPECT_EQ(erle[0], erle[1]);
-    for (size_t k = 1; k < erle.size() - 1; ++k) {
+    constexpr size_t kLowFrequencyLimit = 32;
+    for (size_t k = 1; k < kLowFrequencyLimit; ++k) {
       EXPECT_NEAR(k % 2 == 0 ? 5.f : 1.f, erle[k], 0.1);
     }
+    for (size_t k = kLowFrequencyLimit; k < erle.size() - 1; ++k) {
+      EXPECT_NEAR(k % 2 == 0 ? 1.5f : 1.f, erle[k], 0.1);
+    }
     EXPECT_EQ(erle[erle.size() - 2], erle[erle.size() - 1]);
   }
 }
 
 // Verifies the a non-significant delay is correctly identified.
 TEST(AecState, NonSignificantDelay) {
   AecState state;
   RenderBuffer render_buffer(Aec3Optimization::kNone, 3, 30,
                              std::vector<size_t>(1, 30));
   std::array<float, kFftLengthBy2Plus1> E2_main;
@@ skipping 74 matching lines @@
 
   // Verify that the externally reported delay is properly unset when it is no
   // longer present.
   state.HandleEchoPathChange(EchoPathVariability(false, false));
   state.Update(frequency_response, rtc::Optional<size_t>(), render_buffer,
                E2_main, Y2, x, false);
   EXPECT_FALSE(state.ExternalDelay());
 }
 
 }  // namespace webrtc