Logging basic bad call detection

webrtc/video/quality_threshold_unittest.cc

+/*
+ *  Copyright (c) 2016 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/video/quality_threshold.h"
+
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+TEST(QualityThresholdTest, BackAndForth) {
+  const int kLowThreshold = 0;
+  const int kHighThreshold = 1;
+  const float kFraction = 0.75f;
+  const int kMaxMeasurements = 10;
+
+  QualityThreshold thresh(kLowThreshold, kHighThreshold, kFraction,
+                          kMaxMeasurements);
+
+  const int kNeededMeasurements =
+      static_cast<int>(kFraction * kMaxMeasurements + 1);
+  for (int i = 0; i < kNeededMeasurements; ++i) {
+    EXPECT_FALSE(thresh.IsHigh());
+    thresh.AddMeasurement(kLowThreshold);
+  }
+  ASSERT_TRUE(thresh.IsHigh());
+  for (int i = 0; i < kNeededMeasurements; ++i) {
+    EXPECT_FALSE(*thresh.IsHigh());
+    thresh.AddMeasurement(kHighThreshold);
+  }
+  EXPECT_TRUE(*thresh.IsHigh());
+
+  for (int i = 0; i < kNeededMeasurements; ++i) {
+    EXPECT_TRUE(*thresh.IsHigh());
+    thresh.AddMeasurement(kLowThreshold);
+  }
+  EXPECT_FALSE(*thresh.IsHigh());
+}
+
+TEST(QualityThresholdTest, Variance) {
+  const int kLowThreshold = 0;
+  const int kHighThreshold = 1;
+  const float kFraction = 0.8f;
+  const int kMaxMeasurements = 10;
+  const double kMaxError = 0.01;
+
+  // Previously randomly generated values...
+  int values[] = {51, 79, 80, 56, 19, 20, 48, 57, 48, 25, 2, 25, 38, 37, 25};
+  // ...with precomputed variances.
+  double variances[] = {476.9, 687.6, 552, 336.4, 278.767, 265.167};
+
+  QualityThreshold thresh(kLowThreshold, kHighThreshold, kFraction,
+                          kMaxMeasurements);
+
+  for (int i = 0; i < kMaxMeasurements; ++i) {
+    EXPECT_FALSE(thresh.CalculateVariance());
+    thresh.AddMeasurement(values[i]);
+  }
+
+  ASSERT_TRUE(thresh.CalculateVariance());
+  EXPECT_NEAR(variances[0], *thresh.CalculateVariance(), kMaxError);
+  for (unsigned int i = 1; i < sizeof(variances) / sizeof(double); ++i) {
+    thresh.AddMeasurement(values[i + kMaxMeasurements - 1]);
+    EXPECT_NEAR(variances[i], *thresh.CalculateVariance(), kMaxError);
+  }
+
+  for (int i = 0; i < kMaxMeasurements; ++i) {
+    thresh.AddMeasurement(42);
+  }
+  EXPECT_NEAR(0, *thresh.CalculateVariance(), kMaxError);
+}
+
+TEST(QualityThresholdTest, BetweenThresholds) {
+  const int kLowThreshold = 0;
+  const int kHighThreshold = 2;
+  const float kFraction = 0.6f;
+  const int kMaxMeasurements = 10;
+
+  const int kBetweenThresholds = (kLowThreshold + kHighThreshold) / 2;
+
+  QualityThreshold thresh(kLowThreshold, kHighThreshold, kFraction,
+                          kMaxMeasurements);
+
+  for (int i = 0; i < 2 * kMaxMeasurements; ++i) {
+    EXPECT_FALSE(thresh.IsHigh());
+    thresh.AddMeasurement(kBetweenThresholds);
+  }
+  EXPECT_FALSE(thresh.IsHigh());
+}
+
+}  // namespace webrtc