Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/erl_estimator_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/erl_estimator.h"
+
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+
+void VerifyErl(const std::array<float, kFftLengthBy2Plus1>& erl,
+               float reference) {
+  std::for_each(erl.begin(), erl.end(),
+                [reference](float a) { EXPECT_NEAR(reference, a, 0.001); });
+}
+
+}  // namespace
+
+// Verifies that the correct ERL estimates are achieved.
+TEST(ErlEstimator, Estimates) {
+  std::array<float, kFftLengthBy2Plus1> X2;
+  std::array<float, kFftLengthBy2Plus1> Y2;
+
+  ErlEstimator estimator;
+
+  // Verifies that the ERL estimate is properly reduced to lower values.
+  X2.fill(500 * 1000.f * 1000.f);
+  Y2.fill(10 * X2[0]);
+  for (size_t k = 0; k < 200; ++k) {
+    estimator.Update(X2, Y2);
+  }
+  VerifyErl(estimator.Erl(), 10.f);
+
+  // Verifies that the ERL is not immediately increased when the ERL in the data
+  // increases.
+  Y2.fill(10000 * X2[0]);
+  for (size_t k = 0; k < 998; ++k) {
+    estimator.Update(X2, Y2);
+  }
+  VerifyErl(estimator.Erl(), 10.f);
+
+  // Verifies that the rate of increase is 3 dB.
+  estimator.Update(X2, Y2);
+  VerifyErl(estimator.Erl(), 20.f);
+
+  // Verifies that the maximum ERL is achieved when there are no low RLE
+  // estimates.
+  for (size_t k = 0; k < 1000; ++k) {
+    estimator.Update(X2, Y2);
+  }
+  VerifyErl(estimator.Erl(), 1000.f);
+
+  // Verifies that the ERL estimate is is not updated for low-level signals
+  X2.fill(1000.f * 1000.f);
+  Y2.fill(10 * X2[0]);
+  for (size_t k = 0; k < 200; ++k) {
+    estimator.Update(X2, Y2);
+  }
+  VerifyErl(estimator.Erl(), 1000.f);
+}
+
+}  // namespace webrtc