Move smoothing filter to common audio and exp_filter to base/analytics.

webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter_unittest.cc

Index: webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter_unittest.cc
diff --git a/webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter_unittest.cc b/webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter_unittest.cc
deleted file mode 100644
index af4e8d957b4ed6c793b369d383dc22687b6302d9..0000000000000000000000000000000000000000
--- a/webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter_unittest.cc
+++ /dev/null
@@ -1,108 +0,0 @@
-/*
- *  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 <memory>
-
-#include "webrtc/modules/audio_coding/audio_network_adaptor/smoothing_filter.h"
-#include "webrtc/test/gtest.h"
-
-namespace webrtc {
-
-namespace {
-
-constexpr int kTimeConstantMs = 1000;
-constexpr float kMaxAbsError = 0.0001f;
-constexpr int64_t kClockInitialTime = 123456;
-
-struct SmoothingFilterStates {
-  std::unique_ptr<SimulatedClock> simulated_clock;
-  std::unique_ptr<SmoothingFilter> smoothing_filter;
-};
-
-SmoothingFilterStates CreateSmoothingFilter() {
-  SmoothingFilterStates states;
-  states.simulated_clock.reset(new SimulatedClock(kClockInitialTime));
-  states.smoothing_filter.reset(
-      new SmoothingFilterImpl(kTimeConstantMs, states.simulated_clock.get()));
-  return states;
-}
-
-void CheckOutput(SmoothingFilterStates* states,
-                 int advance_time_ms,
-                 float sample,
-                 float expected_ouput) {
-  states->simulated_clock->AdvanceTimeMilliseconds(advance_time_ms);
-  states->smoothing_filter->AddSample(sample);
-  auto output = states->smoothing_filter->GetAverage();
-  EXPECT_TRUE(output);
-  EXPECT_NEAR(expected_ouput, *output, kMaxAbsError);
-}
-
-}  // namespace
-
-TEST(SmoothingFilterTest, NoOutputWhenNoSampleAdded) {
-  auto states = CreateSmoothingFilter();
-  EXPECT_FALSE(states.smoothing_filter->GetAverage());
-}
-
-// Python script to calculate the reference values used in this test.
-//  import math
-//
-//  class ExpFilter:
-//    alpha = 0.0
-//    old_value = 0.0
-//    def calc(self, new_value):
-//      self.old_value = self.old_value * self.alpha
-//                       + (1.0 - self.alpha) * new_value
-//      return self.old_value
-//
-//  delta_t = 100.0
-//  filter = ExpFilter()
-//  total_t = 100.0
-//  filter.alpha = math.exp(-delta_t/ total_t)
-//  print filter.calc(1.0)
-//  total_t = 200.0
-//  filter.alpha = math.exp(-delta_t/ total_t)
-//  print filter.calc(0.0)
-//  total_t = 300.0
-//  filter.alpha = math.exp(-delta_t/ total_t)
-//  print filter.calc(1.0)
-TEST(SmoothingFilterTest, CheckBehaviorBeforeInitialized) {
-  // Adding three samples, all added before |kTimeConstantMs| is reached.
-  constexpr int kTimeIntervalMs = 100;
-  auto states = CreateSmoothingFilter();
-  states.smoothing_filter->AddSample(0.0);
-  CheckOutput(&states, kTimeIntervalMs, 1.0, 0.63212f);
-  CheckOutput(&states, kTimeIntervalMs, 0.0, 0.38340f);
-  CheckOutput(&states, kTimeIntervalMs, 1.0, 0.55818f);
-}
-
-// Python script to calculate the reference value used in this test.
-// (after defining ExpFilter as for CheckBehaviorBeforeInitialized)
-//  time_constant_ms = 1000.0
-//  filter = ExpFilter()
-//  delta_t = 1100.0
-//  filter.alpha = math.exp(-delta_t/ time_constant_ms)
-//  print filter.calc(1.0)
-//  delta_t = 100.0
-//  filter.alpha = math.exp(-delta_t/ time_constant_ms)
-//  print filter.calc(0.0)
-//  print filter.calc(1.0)
-TEST(SmoothingFilterTest, CheckBehaviorAfterInitialized) {
-  constexpr int kTimeIntervalMs = 100;
-  auto states = CreateSmoothingFilter();
-  states.smoothing_filter->AddSample(0.0);
-  states.simulated_clock->AdvanceTimeMilliseconds(kTimeConstantMs);
-  CheckOutput(&states, kTimeIntervalMs, 1.0, 0.66713f);
-  CheckOutput(&states, kTimeIntervalMs, 0.0, 0.60364f);
-  CheckOutput(&states, kTimeIntervalMs, 1.0, 0.64136f);
-}
-
-}  // namespace webrtc