Add new variance update option and unittests for intelligibility

webrtc/modules/audio_processing/intelligibility/test/utils_unittest.cc

+/*
+ *  Copyright (c) 2014 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.
+ */
+
+//
+//  Unit tests for intelligibility utils.
+//
+
+
+#include <cmath>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc"

[turaj, 2015/06/26 00:32:58]

Do you need to include .cc file?

[ekm, 2015/06/26 19:07:10]

This is to test functions from anonymous namespace. Is that ok since this is
just a test, or would it be better to refactor .cc file to make testing easier?
or not test these helper methods at all, since they are pretty simple?

[turaj, 2015/06/29 17:33:36]

If you feel that they are simple and don't need test it is fine by me.
Otherwise, like you suggested, we need a header for them. Although this is only
a test but I don't think it is good idea to include .cc. 

[ekm, 2015/06/29 23:44:02]

Added them to the intelligibility namespace.

+#include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h"
+
+namespace webrtc {
+
+using std::complex;
+using intelligibility::VarianceArray;
+using intelligibility::GainApplier;
+using std::vector;
+
+vector<vector<complex<float>>> GenerateTestData(int freqs, int samples) {
+  vector<vector<complex<float>>> data(samples);
+  for (int i = 0; i < samples; i++) {
+    data[i].resize(freqs);
+    for (int j = 0; j < freqs; j++) {
+      data[i][j].real(0.99f / ((i+1)*(j+1)));
+      data[i][j].imag(0.99f / ((i+1)*(j+1)));
+    }
+  }
+  return data;
+}
+
+// Tests UpdateFactor.
+TEST(UtilsTest, TestUpdateFactor) {
+  EXPECT_EQ(UpdateFactor(0, 0, 0), 0);
+  EXPECT_EQ(UpdateFactor(4, 2, 3), 4);
+  EXPECT_EQ(UpdateFactor(4, 2, 1), 3);
+  EXPECT_EQ(UpdateFactor(2, 4, 3), 2);
+  EXPECT_EQ(UpdateFactor(2, 4, 1), 3);
+}
+
+// Tests cplxfinite, cplxnormal, and zerofudge.
+TEST(UtilsTest, TestCplx) {
+  complex<float> t;
+  t.real(1.f);
+  t.imag(0.f);
+  EXPECT_TRUE(cplxfinite(t));
+  EXPECT_FALSE(cplxnormal(t));
+  t = zerofudge(t);
+  EXPECT_GT(t.imag(), 0.f);

[turaj, 2015/06/26 00:32:58]

I guess EXPECT_NE() is a better choice here.

[ekm, 2015/06/26 19:07:10]

Done.

+  EXPECT_GT(t.real(), 0.f);
+  t.imag(1.f/0.f);
+  EXPECT_FALSE(cplxfinite(t));
+  EXPECT_FALSE(cplxnormal(t));
+  t.imag(sqrt(-1.f));
+  EXPECT_FALSE(cplxfinite(t));
+  EXPECT_FALSE(cplxnormal(t));
+  t.imag(1.f);
+  EXPECT_TRUE(cplxfinite(t));
+  EXPECT_TRUE(cplxnormal(t));
+}
+
+// Tests NewMean and AddToMean.
+TEST(UtilsTest, TestMeanUpdate) {
+  vector<complex<float>> data = {{3, 8}, {7, 6}, {2, 1}, {8, 9}, {0, 6}};
+  vector<complex<float>> means = {{3, 8}, {5, 7}, {4, 5}, {5, 6}, {4, 6}};
+  complex<float> mean(3, 8);
+  for (vector<int>::size_type i = 0; i < data.size(); i++) {
+    EXPECT_EQ(NewMean(mean, data[i], i+1), means[i]);
+    AddToMean(data[i], i+1, &mean);
+    EXPECT_EQ(mean, means[i]);
+  }
+}
+
+// Tests VarianceArray, for all variance step types.
+TEST(UtilsTest, TestVarianceArray) {
+  const int kFreqs = 10;
+  const int kSamples = 100;
+  const int kWindowSize = 10;  // Should pass for all kWindowSize > 1.
+  const float kDecay = 0.5;
+  vector<VarianceArray::StepType> step_types = {
+      VarianceArray::kStepInfinite, VarianceArray::kStepDecaying,
+      VarianceArray::kStepWindowed, VarianceArray::kStepBlocked,
+      VarianceArray::kStepBlockBasedMovingAverage};
+  const vector<vector<complex<float>>> test_data(
+      GenerateTestData(kFreqs, kSamples));
+  for (vector<VarianceArray::StepType>::iterator step_type =
+      step_types.begin(); step_type != step_types.end(); ++step_type) {
+    VarianceArray variance_array(kFreqs, *step_type, kWindowSize, kDecay);
+    EXPECT_EQ(variance_array.variance()[0], 0);
+    EXPECT_EQ(variance_array.array_mean(), 0);
+    variance_array.Clear();

[turaj, 2015/06/26 00:32:58]

Can we move the for Clear() after following loop? Then we are sure it is doing
the expected job.

[ekm, 2015/06/26 19:07:10]

Done.

+    EXPECT_EQ(variance_array.variance()[0], 0);
+    EXPECT_EQ(variance_array.array_mean(), 0);
+    variance_array.ApplyScale(2.0f);
+    EXPECT_EQ(variance_array.variance()[0], 0);
+    EXPECT_EQ(variance_array.array_mean(), 0);
+
+    // Makes sure Step is doing something.
+    variance_array.Step(&test_data[0][0]);
+    for (int i = 1; i < kSamples; i++) {
+      variance_array.Step(&test_data[i][0]);
+      EXPECT_GE(variance_array.array_mean(), 0.0f);
+      EXPECT_LE(variance_array.array_mean(), 1.0f);
+      for (int j = 0; j < kFreqs; j++) {
+        EXPECT_GE(variance_array.variance()[j], 0.0f);
+        EXPECT_LE(variance_array.variance()[j], 1.0f);
+      }
+    }
+  }
+}
+
+// Tests exact computation on synthetic data.
+TEST(UtilsTest, TestMovingBlockAverage) {
+  const float kTestVariance = 8.25;  // Exact, not unbiased estimate.
+  const int kFreqs = 2;
+  const int kSamples = 30;
+  const int kWindowSize = 1;

[turaj, 2015/06/26 00:32:58]

Does window size of one actually test the circular buffer of the keep track
block mean and block mean of square? How about the window size of 2?

[ekm, 2015/06/26 19:07:10]

Done.

+  const float kDecay = 0.5;
+  const float kMaxError = 0.001;
+
+  VarianceArray variance_array(
+      kFreqs, VarianceArray::kStepBlockBasedMovingAverage,
+      kWindowSize, kDecay);
+
+  vector<vector<complex<float>>> test_data(kSamples);
+  for (int i = 0; i < kSamples; i++) {
+    test_data[i].resize(kFreqs);
+    for (int j = 0; j < kFreqs; j++) {
+      test_data[i][j].real(static_cast<float>(i+1));
+      test_data[i][j].imag(0.f);

[turaj, 2015/06/26 00:32:58]

Can we have non-zero imaginary part to be sure the complex computations are
correct?

[ekm, 2015/06/26 19:07:10]

Done.

+    }
+  }
+
+  for (int i = 0; i < kSamples; i++) {
+    variance_array.Step(&test_data[i][0]);
+    for (int j = 0; j < kFreqs; j++) {
+      if (i < 9) {  // In utils, kWindowBlockSize = 10.
+        EXPECT_EQ(variance_array.variance()[j], 0);
+      } else {
+        float error = std::fabs(
+            variance_array.variance()[j] - kTestVariance);
+        EXPECT_LT(error, kMaxError);
+      }
+    }
+  }
+}
+
+// Tests gain applier.
+TEST(UtilsTest, TestGainApplier) {
+  const int kFreqs = 10;
+  const int kSamples = 100;
+  const float kChangeLimit = 0.1f;
+  GainApplier gain_applier(kFreqs, kChangeLimit);
+  const vector<vector<complex<float>>> in_data(
+      GenerateTestData(kFreqs, kSamples));
+  vector<vector<complex<float>>> out_data(
+      GenerateTestData(kFreqs, kSamples));
+  for (int i = 0; i < kSamples; i++) {
+    gain_applier.Apply(&in_data[i][0], &out_data[i][0]);
+    for (int j = 0; j < kFreqs; j++) {
+      EXPECT_GT(out_data[i][j].real(), 0.0f);
+      EXPECT_LT(out_data[i][j].real(), 1.0f);
+      EXPECT_GT(out_data[i][j].imag(), 0.0f);
+      EXPECT_LT(out_data[i][j].imag(), 1.0f);
+    }
+  }
+}
+
+}  // namespace webrtc