minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
Jonas Olsson | a4d8737 | 2019-07-05 19:08:33 +0200 | [diff] [blame] | 11 | #include "common_audio/smoothing_filter.h" |
| 12 | |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 13 | #include <cmath> |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 14 | #include <memory> |
| 15 | |
Steve Anton | 10542f2 | 2019-01-11 09:11:00 -0800 | [diff] [blame] | 16 | #include "rtc_base/fake_clock.h" |
Mirko Bonadei | 92ea95e | 2017-09-15 06:47:31 +0200 | [diff] [blame] | 17 | #include "test/gtest.h" |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 18 | |
| 19 | namespace webrtc { |
| 20 | |
| 21 | namespace { |
| 22 | |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 23 | constexpr float kMaxAbsError = 1e-5f; |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 24 | constexpr int64_t kClockInitialTime = 123456; |
| 25 | |
| 26 | struct SmoothingFilterStates { |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 27 | explicit SmoothingFilterStates(int init_time_ms) |
| 28 | : smoothing_filter(init_time_ms) { |
Sebastian Jansson | 5f83cf0 | 2018-05-08 14:52:22 +0200 | [diff] [blame] | 29 | fake_clock.AdvanceTime(TimeDelta::ms(kClockInitialTime)); |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 30 | } |
| 31 | rtc::ScopedFakeClock fake_clock; |
| 32 | SmoothingFilterImpl smoothing_filter; |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 33 | }; |
| 34 | |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 35 | // This function does the following: |
| 36 | // 1. Add a sample to filter at current clock, |
| 37 | // 2. Advance the clock by |advance_time_ms|, |
| 38 | // 3. Get the output of both SmoothingFilter and verify that it equals to an |
| 39 | // expected value. |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 40 | void CheckOutput(SmoothingFilterStates* states, |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 41 | float sample, |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 42 | int advance_time_ms, |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 43 | float expected_ouput) { |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 44 | states->smoothing_filter.AddSample(sample); |
Sebastian Jansson | 5f83cf0 | 2018-05-08 14:52:22 +0200 | [diff] [blame] | 45 | states->fake_clock.AdvanceTime(TimeDelta::ms(advance_time_ms)); |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 46 | auto output = states->smoothing_filter.GetAverage(); |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 47 | EXPECT_TRUE(output); |
| 48 | EXPECT_NEAR(expected_ouput, *output, kMaxAbsError); |
| 49 | } |
| 50 | |
| 51 | } // namespace |
| 52 | |
| 53 | TEST(SmoothingFilterTest, NoOutputWhenNoSampleAdded) { |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 54 | constexpr int kInitTimeMs = 100; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 55 | SmoothingFilterStates states(kInitTimeMs); |
| 56 | EXPECT_FALSE(states.smoothing_filter.GetAverage()); |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 57 | } |
| 58 | |
| 59 | // Python script to calculate the reference values used in this test. |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 60 | // import math |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 61 | // |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 62 | // class ExpFilter: |
| 63 | // def add_sample(self, new_value): |
| 64 | // self.state = self.state * self.alpha + (1.0 - self.alpha) * new_value |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 65 | // |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 66 | // filter = ExpFilter() |
| 67 | // init_time = 795 |
| 68 | // init_factor = (1.0 / init_time) ** (1.0 / init_time) |
| 69 | // |
| 70 | // filter.state = 1.0 |
| 71 | // |
| 72 | // for time_now in range(1, 500): |
| 73 | // filter.alpha = math.exp(-init_factor ** time_now) |
| 74 | // filter.add_sample(1.0) |
| 75 | // print filter.state |
| 76 | // |
| 77 | // for time_now in range(500, 600): |
| 78 | // filter.alpha = math.exp(-init_factor ** time_now) |
| 79 | // filter.add_sample(0.5) |
| 80 | // print filter.state |
| 81 | // |
| 82 | // for time_now in range(600, 700): |
| 83 | // filter.alpha = math.exp(-init_factor ** time_now) |
| 84 | // filter.add_sample(1.0) |
| 85 | // print filter.state |
| 86 | // |
| 87 | // for time_now in range(700, init_time): |
| 88 | // filter.alpha = math.exp(-init_factor ** time_now) |
| 89 | // filter.add_sample(1.0) |
| 90 | // |
| 91 | // filter.alpha = math.exp(-1.0 / init_time) |
| 92 | // for time_now in range(init_time, 800): |
| 93 | // filter.add_sample(1.0) |
| 94 | // print filter.state |
| 95 | // |
| 96 | // for i in range(800, 900): |
| 97 | // filter.add_sample(0.5) |
| 98 | // print filter.state |
| 99 | // |
| 100 | // for i in range(900, 1000): |
| 101 | // filter.add_sample(1.0) |
| 102 | // print filter.state |
| 103 | TEST(SmoothingFilterTest, CheckBehaviorAroundInitTime) { |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 104 | constexpr int kInitTimeMs = 795; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 105 | SmoothingFilterStates states(kInitTimeMs); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 106 | CheckOutput(&states, 1.0f, 500, 1.0f); |
| 107 | CheckOutput(&states, 0.5f, 100, 0.680562264029f); |
| 108 | CheckOutput(&states, 1.0f, 100, 0.794207139813f); |
| 109 | // Next step will go across initialization time. |
| 110 | CheckOutput(&states, 1.0f, 100, 0.829803409752f); |
| 111 | CheckOutput(&states, 0.5f, 100, 0.790821764210f); |
| 112 | CheckOutput(&states, 1.0f, 100, 0.815545922911f); |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 113 | } |
| 114 | |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 115 | TEST(SmoothingFilterTest, InitTimeEqualsZero) { |
| 116 | constexpr int kInitTimeMs = 0; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 117 | SmoothingFilterStates states(kInitTimeMs); |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 118 | CheckOutput(&states, 1.0f, 1, 1.0f); |
| 119 | CheckOutput(&states, 0.5f, 1, 0.5f); |
| 120 | } |
| 121 | |
| 122 | TEST(SmoothingFilterTest, InitTimeEqualsOne) { |
| 123 | constexpr int kInitTimeMs = 1; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 124 | SmoothingFilterStates states(kInitTimeMs); |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 125 | CheckOutput(&states, 1.0f, 1, 1.0f); |
Mirko Bonadei | b00dec5 | 2019-03-25 09:31:06 +0100 | [diff] [blame] | 126 | CheckOutput(&states, 0.5f, 1, |
| 127 | 1.0f * std::exp(-1.0f) + (1.0f - std::exp(-1.0f)) * 0.5f); |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 128 | } |
| 129 | |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 130 | TEST(SmoothingFilterTest, GetAverageOutputsEmptyBeforeFirstSample) { |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 131 | constexpr int kInitTimeMs = 100; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 132 | SmoothingFilterStates states(kInitTimeMs); |
| 133 | EXPECT_FALSE(states.smoothing_filter.GetAverage()); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 134 | constexpr float kFirstSample = 1.2345f; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 135 | states.smoothing_filter.AddSample(kFirstSample); |
Oskar Sundbom | 5e1a749 | 2017-11-16 10:57:19 +0100 | [diff] [blame] | 136 | EXPECT_EQ(kFirstSample, states.smoothing_filter.GetAverage()); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 137 | } |
| 138 | |
| 139 | TEST(SmoothingFilterTest, CannotChangeTimeConstantDuringInitialization) { |
minyue | 7667db4 | 2016-12-28 02:57:50 -0800 | [diff] [blame] | 140 | constexpr int kInitTimeMs = 100; |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 141 | SmoothingFilterStates states(kInitTimeMs); |
| 142 | states.smoothing_filter.AddSample(0.0); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 143 | |
| 144 | // During initialization, |SetTimeConstantMs| does not take effect. |
Sebastian Jansson | 5f83cf0 | 2018-05-08 14:52:22 +0200 | [diff] [blame] | 145 | states.fake_clock.AdvanceTime(TimeDelta::ms(kInitTimeMs - 1)); |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 146 | states.smoothing_filter.AddSample(0.0); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 147 | |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 148 | EXPECT_FALSE(states.smoothing_filter.SetTimeConstantMs(kInitTimeMs * 2)); |
Mirko Bonadei | b00dec5 | 2019-03-25 09:31:06 +0100 | [diff] [blame] | 149 | EXPECT_NE(std::exp(-1.0f / (kInitTimeMs * 2)), |
| 150 | states.smoothing_filter.alpha()); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 151 | |
Sebastian Jansson | 5f83cf0 | 2018-05-08 14:52:22 +0200 | [diff] [blame] | 152 | states.fake_clock.AdvanceTime(TimeDelta::ms(1)); |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 153 | states.smoothing_filter.AddSample(0.0); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 154 | // When initialization finishes, the time constant should be come |
| 155 | // |kInitTimeConstantMs|. |
Mirko Bonadei | b00dec5 | 2019-03-25 09:31:06 +0100 | [diff] [blame] | 156 | EXPECT_FLOAT_EQ(std::exp(-1.0f / kInitTimeMs), |
| 157 | states.smoothing_filter.alpha()); |
minyue | 301fc4a | 2016-12-13 06:52:56 -0800 | [diff] [blame] | 158 | |
| 159 | // After initialization, |SetTimeConstantMs| takes effect. |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 160 | EXPECT_TRUE(states.smoothing_filter.SetTimeConstantMs(kInitTimeMs * 2)); |
Mirko Bonadei | b00dec5 | 2019-03-25 09:31:06 +0100 | [diff] [blame] | 161 | EXPECT_FLOAT_EQ(std::exp(-1.0f / (kInitTimeMs * 2)), |
michaelt | 92aef17 | 2017-04-18 00:11:48 -0700 | [diff] [blame] | 162 | states.smoothing_filter.alpha()); |
minyue | 3548357 | 2016-09-20 23:13:08 -0700 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | } // namespace webrtc |