Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/output_selector_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/output_selector.h"
+
+#include <algorithm>
+#include <array>
+
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+// Verifies that the switching between the signals in the output works as
+// intended.
+TEST(OutputSelector, ProperSwitching) {
+  OutputSelector selector;
+
+  constexpr int kNumBlocksToSwitchToSubtractor = 3;
+  constexpr int kNumBlocksToSwitchFromSubtractor = 10;
+
+  std::array<float, kBlockSize> weaker;
+  std::array<float, kBlockSize> stronger;
+  std::array<float, kBlockSize> y;
+  std::array<float, kBlockSize> e;
+  weaker.fill(10.f);
+  stronger.fill(20.f);
+
+  bool y_is_weakest = false;
+
+  const auto form_e_and_y = [&](bool y_equals_weaker) {
+    if (y_equals_weaker) {
+      std::copy(weaker.begin(), weaker.end(), y.begin());
+      std::copy(stronger.begin(), stronger.end(), e.begin());
+    } else {
+      std::copy(stronger.begin(), stronger.end(), y.begin());
+      std::copy(weaker.begin(), weaker.end(), e.begin());
+    }
+  };
+
+  for (int k = 0; k < 30; ++k) {
+    // Verify that it takes a while for the signals transition to take effect.
+    const int num_blocks_to_switch = y_is_weakest
+                                         ? kNumBlocksToSwitchFromSubtractor
+                                         : kNumBlocksToSwitchToSubtractor;
+    for (int j = 0; j < num_blocks_to_switch; ++j) {
+      form_e_and_y(y_is_weakest);
+      selector.FormLinearOutput(e, y);
+      EXPECT_EQ(stronger, y);
+      EXPECT_EQ(y_is_weakest, selector.UseSubtractorOutput());
+    }
+
+    // Verify that the transition block is a mix between the signals.
+    form_e_and_y(y_is_weakest);
+    selector.FormLinearOutput(e, y);
+    EXPECT_NE(weaker, y);
+    EXPECT_NE(stronger, y);
+    EXPECT_EQ(!y_is_weakest, selector.UseSubtractorOutput());
+
+    y_is_weakest = !y_is_weakest;
+  }
+}
+
+}  // namespace webrtc