1 /*
2 * Copyright (c) 2017 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
11 #include "modules/audio_processing/gain_controller2.h"
12
13 #include <algorithm>
14 #include <cmath>
15 #include <memory>
16
17 #include "api/array_view.h"
18 #include "modules/audio_processing/agc2/agc2_testing_common.h"
19 #include "modules/audio_processing/audio_buffer.h"
20 #include "modules/audio_processing/test/audio_buffer_tools.h"
21 #include "modules/audio_processing/test/bitexactness_tools.h"
22 #include "rtc_base/checks.h"
23 #include "test/gtest.h"
24
25 namespace webrtc {
26 namespace test {
27 namespace {
28
SetAudioBufferSamples(float value,AudioBuffer * ab)29 void SetAudioBufferSamples(float value, AudioBuffer* ab) {
30 // Sets all the samples in |ab| to |value|.
31 for (size_t k = 0; k < ab->num_channels(); ++k) {
32 std::fill(ab->channels()[k], ab->channels()[k] + ab->num_frames(), value);
33 }
34 }
35
RunAgc2WithConstantInput(GainController2 * agc2,float input_level,size_t num_frames,int sample_rate)36 float RunAgc2WithConstantInput(GainController2* agc2,
37 float input_level,
38 size_t num_frames,
39 int sample_rate) {
40 const int num_samples = rtc::CheckedDivExact(sample_rate, 100);
41 AudioBuffer ab(sample_rate, 1, sample_rate, 1, sample_rate, 1);
42
43 // Give time to the level estimator to converge.
44 for (size_t i = 0; i < num_frames + 1; ++i) {
45 SetAudioBufferSamples(input_level, &ab);
46 agc2->Process(&ab);
47 }
48
49 // Return the last sample from the last processed frame.
50 return ab.channels()[0][num_samples - 1];
51 }
52
CreateAgc2FixedDigitalModeConfig(float fixed_gain_db)53 AudioProcessing::Config::GainController2 CreateAgc2FixedDigitalModeConfig(
54 float fixed_gain_db) {
55 AudioProcessing::Config::GainController2 config;
56 config.adaptive_digital.enabled = false;
57 config.fixed_digital.gain_db = fixed_gain_db;
58 // TODO(alessiob): Check why ASSERT_TRUE() below does not compile.
59 EXPECT_TRUE(GainController2::Validate(config));
60 return config;
61 }
62
CreateAgc2FixedDigitalMode(float fixed_gain_db,size_t sample_rate_hz)63 std::unique_ptr<GainController2> CreateAgc2FixedDigitalMode(
64 float fixed_gain_db,
65 size_t sample_rate_hz) {
66 auto agc2 = std::make_unique<GainController2>();
67 agc2->ApplyConfig(CreateAgc2FixedDigitalModeConfig(fixed_gain_db));
68 agc2->Initialize(sample_rate_hz);
69 return agc2;
70 }
71
GainDbAfterProcessingFile(GainController2 & gain_controller,int max_duration_ms)72 float GainDbAfterProcessingFile(GainController2& gain_controller,
73 int max_duration_ms) {
74 // Set up an AudioBuffer to be filled from the speech file.
75 constexpr size_t kStereo = 2u;
76 const StreamConfig capture_config(AudioProcessing::kSampleRate48kHz, kStereo,
77 false);
78 AudioBuffer ab(capture_config.sample_rate_hz(), capture_config.num_channels(),
79 capture_config.sample_rate_hz(), capture_config.num_channels(),
80 capture_config.sample_rate_hz(),
81 capture_config.num_channels());
82 test::InputAudioFile capture_file(
83 test::GetApmCaptureTestVectorFileName(AudioProcessing::kSampleRate48kHz));
84 std::vector<float> capture_input(capture_config.num_frames() *
85 capture_config.num_channels());
86
87 // Process the input file which must be long enough to cover
88 // `max_duration_ms`.
89 RTC_DCHECK_GT(max_duration_ms, 0);
90 const int num_frames = rtc::CheckedDivExact(max_duration_ms, 10);
91 for (int i = 0; i < num_frames; ++i) {
92 ReadFloatSamplesFromStereoFile(capture_config.num_frames(),
93 capture_config.num_channels(), &capture_file,
94 capture_input);
95 test::CopyVectorToAudioBuffer(capture_config, capture_input, &ab);
96 gain_controller.Process(&ab);
97 }
98
99 // Send in a last frame with minimum dBFS level.
100 constexpr float sample_value = 1.f;
101 SetAudioBufferSamples(sample_value, &ab);
102 gain_controller.Process(&ab);
103 // Measure the RMS level after processing.
104 float rms = 0.0f;
105 for (size_t i = 0; i < capture_config.num_frames(); ++i) {
106 rms += ab.channels()[0][i] * ab.channels()[0][i];
107 }
108 // Return the applied gain in dB.
109 return 20.0f * std::log10(std::sqrt(rms / capture_config.num_frames()));
110 }
111
112 } // namespace
113
TEST(GainController2,CheckDefaultConfig)114 TEST(GainController2, CheckDefaultConfig) {
115 AudioProcessing::Config::GainController2 config;
116 EXPECT_TRUE(GainController2::Validate(config));
117 }
118
TEST(GainController2,CheckFixedDigitalConfig)119 TEST(GainController2, CheckFixedDigitalConfig) {
120 AudioProcessing::Config::GainController2 config;
121 // Attenuation is not allowed.
122 config.fixed_digital.gain_db = -5.f;
123 EXPECT_FALSE(GainController2::Validate(config));
124 // No gain is allowed.
125 config.fixed_digital.gain_db = 0.f;
126 EXPECT_TRUE(GainController2::Validate(config));
127 // Positive gain is allowed.
128 config.fixed_digital.gain_db = 15.f;
129 EXPECT_TRUE(GainController2::Validate(config));
130 }
131
TEST(GainController2,CheckAdaptiveDigitalVadProbabilityAttackConfig)132 TEST(GainController2, CheckAdaptiveDigitalVadProbabilityAttackConfig) {
133 AudioProcessing::Config::GainController2 config;
134 // Reject invalid attack.
135 config.adaptive_digital.vad_probability_attack = -123.f;
136 EXPECT_FALSE(GainController2::Validate(config));
137 config.adaptive_digital.vad_probability_attack = 0.f;
138 EXPECT_FALSE(GainController2::Validate(config));
139 config.adaptive_digital.vad_probability_attack = 42.f;
140 EXPECT_FALSE(GainController2::Validate(config));
141 // Accept valid attack.
142 config.adaptive_digital.vad_probability_attack = 0.1f;
143 EXPECT_TRUE(GainController2::Validate(config));
144 config.adaptive_digital.vad_probability_attack = 1.f;
145 EXPECT_TRUE(GainController2::Validate(config));
146 }
147
TEST(GainController2,CheckAdaptiveDigitalLevelEstimatorSpeechFramesThresholdConfig)148 TEST(GainController2,
149 CheckAdaptiveDigitalLevelEstimatorSpeechFramesThresholdConfig) {
150 AudioProcessing::Config::GainController2 config;
151 config.adaptive_digital.level_estimator_adjacent_speech_frames_threshold = 0;
152 EXPECT_FALSE(GainController2::Validate(config));
153 config.adaptive_digital.level_estimator_adjacent_speech_frames_threshold = 1;
154 EXPECT_TRUE(GainController2::Validate(config));
155 config.adaptive_digital.level_estimator_adjacent_speech_frames_threshold = 7;
156 EXPECT_TRUE(GainController2::Validate(config));
157 }
158
TEST(GainController2,CheckAdaptiveDigitalInitialSaturationMarginConfig)159 TEST(GainController2, CheckAdaptiveDigitalInitialSaturationMarginConfig) {
160 AudioProcessing::Config::GainController2 config;
161 config.adaptive_digital.initial_saturation_margin_db = -1.f;
162 EXPECT_FALSE(GainController2::Validate(config));
163 config.adaptive_digital.initial_saturation_margin_db = 0.f;
164 EXPECT_TRUE(GainController2::Validate(config));
165 config.adaptive_digital.initial_saturation_margin_db = 50.f;
166 EXPECT_TRUE(GainController2::Validate(config));
167 }
168
TEST(GainController2,CheckAdaptiveDigitalExtraSaturationMarginConfig)169 TEST(GainController2, CheckAdaptiveDigitalExtraSaturationMarginConfig) {
170 AudioProcessing::Config::GainController2 config;
171 config.adaptive_digital.extra_saturation_margin_db = -1.f;
172 EXPECT_FALSE(GainController2::Validate(config));
173 config.adaptive_digital.extra_saturation_margin_db = 0.f;
174 EXPECT_TRUE(GainController2::Validate(config));
175 config.adaptive_digital.extra_saturation_margin_db = 50.f;
176 EXPECT_TRUE(GainController2::Validate(config));
177 }
178
TEST(GainController2,CheckAdaptiveDigitalGainApplierSpeechFramesThresholdConfig)179 TEST(GainController2,
180 CheckAdaptiveDigitalGainApplierSpeechFramesThresholdConfig) {
181 AudioProcessing::Config::GainController2 config;
182 config.adaptive_digital.gain_applier_adjacent_speech_frames_threshold = 0;
183 EXPECT_FALSE(GainController2::Validate(config));
184 config.adaptive_digital.gain_applier_adjacent_speech_frames_threshold = 1;
185 EXPECT_TRUE(GainController2::Validate(config));
186 config.adaptive_digital.gain_applier_adjacent_speech_frames_threshold = 7;
187 EXPECT_TRUE(GainController2::Validate(config));
188 }
189
TEST(GainController2,CheckAdaptiveDigitalMaxGainChangeSpeedConfig)190 TEST(GainController2, CheckAdaptiveDigitalMaxGainChangeSpeedConfig) {
191 AudioProcessing::Config::GainController2 config;
192 config.adaptive_digital.max_gain_change_db_per_second = -1.f;
193 EXPECT_FALSE(GainController2::Validate(config));
194 config.adaptive_digital.max_gain_change_db_per_second = 0.f;
195 EXPECT_FALSE(GainController2::Validate(config));
196 config.adaptive_digital.max_gain_change_db_per_second = 5.f;
197 EXPECT_TRUE(GainController2::Validate(config));
198 }
199
TEST(GainController2,CheckAdaptiveDigitalMaxOutputNoiseLevelConfig)200 TEST(GainController2, CheckAdaptiveDigitalMaxOutputNoiseLevelConfig) {
201 AudioProcessing::Config::GainController2 config;
202 config.adaptive_digital.max_output_noise_level_dbfs = 5.f;
203 EXPECT_FALSE(GainController2::Validate(config));
204 config.adaptive_digital.max_output_noise_level_dbfs = 0.f;
205 EXPECT_TRUE(GainController2::Validate(config));
206 config.adaptive_digital.max_output_noise_level_dbfs = -5.f;
207 EXPECT_TRUE(GainController2::Validate(config));
208 }
209
210 // Checks that the default config is applied.
TEST(GainController2,ApplyDefaultConfig)211 TEST(GainController2, ApplyDefaultConfig) {
212 auto gain_controller2 = std::make_unique<GainController2>();
213 AudioProcessing::Config::GainController2 config;
214 gain_controller2->ApplyConfig(config);
215 }
216
TEST(GainController2FixedDigital,GainShouldChangeOnSetGain)217 TEST(GainController2FixedDigital, GainShouldChangeOnSetGain) {
218 constexpr float kInputLevel = 1000.f;
219 constexpr size_t kNumFrames = 5;
220 constexpr size_t kSampleRateHz = 8000;
221 constexpr float kGain0Db = 0.f;
222 constexpr float kGain20Db = 20.f;
223
224 auto agc2_fixed = CreateAgc2FixedDigitalMode(kGain0Db, kSampleRateHz);
225
226 // Signal level is unchanged with 0 db gain.
227 EXPECT_FLOAT_EQ(RunAgc2WithConstantInput(agc2_fixed.get(), kInputLevel,
228 kNumFrames, kSampleRateHz),
229 kInputLevel);
230
231 // +20 db should increase signal by a factor of 10.
232 agc2_fixed->ApplyConfig(CreateAgc2FixedDigitalModeConfig(kGain20Db));
233 EXPECT_FLOAT_EQ(RunAgc2WithConstantInput(agc2_fixed.get(), kInputLevel,
234 kNumFrames, kSampleRateHz),
235 kInputLevel * 10);
236 }
237
TEST(GainController2FixedDigital,ChangeFixedGainShouldBeFastAndTimeInvariant)238 TEST(GainController2FixedDigital, ChangeFixedGainShouldBeFastAndTimeInvariant) {
239 // Number of frames required for the fixed gain controller to adapt on the
240 // input signal when the gain changes.
241 constexpr size_t kNumFrames = 5;
242
243 constexpr float kInputLevel = 1000.f;
244 constexpr size_t kSampleRateHz = 8000;
245 constexpr float kGainDbLow = 0.f;
246 constexpr float kGainDbHigh = 25.f;
247 static_assert(kGainDbLow < kGainDbHigh, "");
248
249 auto agc2_fixed = CreateAgc2FixedDigitalMode(kGainDbLow, kSampleRateHz);
250
251 // Start with a lower gain.
252 const float output_level_pre = RunAgc2WithConstantInput(
253 agc2_fixed.get(), kInputLevel, kNumFrames, kSampleRateHz);
254
255 // Increase gain.
256 agc2_fixed->ApplyConfig(CreateAgc2FixedDigitalModeConfig(kGainDbHigh));
257 static_cast<void>(RunAgc2WithConstantInput(agc2_fixed.get(), kInputLevel,
258 kNumFrames, kSampleRateHz));
259
260 // Back to the lower gain.
261 agc2_fixed->ApplyConfig(CreateAgc2FixedDigitalModeConfig(kGainDbLow));
262 const float output_level_post = RunAgc2WithConstantInput(
263 agc2_fixed.get(), kInputLevel, kNumFrames, kSampleRateHz);
264
265 EXPECT_EQ(output_level_pre, output_level_post);
266 }
267
268 struct FixedDigitalTestParams {
FixedDigitalTestParamswebrtc::test::FixedDigitalTestParams269 FixedDigitalTestParams(float gain_db_min,
270 float gain_db_max,
271 size_t sample_rate,
272 bool saturation_expected)
273 : gain_db_min(gain_db_min),
274 gain_db_max(gain_db_max),
275 sample_rate(sample_rate),
276 saturation_expected(saturation_expected) {}
277 float gain_db_min;
278 float gain_db_max;
279 size_t sample_rate;
280 bool saturation_expected;
281 };
282
283 class FixedDigitalTest
284 : public ::testing::Test,
285 public ::testing::WithParamInterface<FixedDigitalTestParams> {};
286
TEST_P(FixedDigitalTest,CheckSaturationBehaviorWithLimiter)287 TEST_P(FixedDigitalTest, CheckSaturationBehaviorWithLimiter) {
288 const float kInputLevel = 32767.f;
289 const size_t kNumFrames = 5;
290
291 const auto params = GetParam();
292
293 const auto gains_db =
294 test::LinSpace(params.gain_db_min, params.gain_db_max, 10);
295 for (const auto gain_db : gains_db) {
296 SCOPED_TRACE(std::to_string(gain_db));
297 auto agc2_fixed = CreateAgc2FixedDigitalMode(gain_db, params.sample_rate);
298 const float processed_sample = RunAgc2WithConstantInput(
299 agc2_fixed.get(), kInputLevel, kNumFrames, params.sample_rate);
300 if (params.saturation_expected) {
301 EXPECT_FLOAT_EQ(processed_sample, 32767.f);
302 } else {
303 EXPECT_LT(processed_sample, 32767.f);
304 }
305 }
306 }
307
308 static_assert(test::kLimiterMaxInputLevelDbFs < 10, "");
309 INSTANTIATE_TEST_SUITE_P(
310 GainController2,
311 FixedDigitalTest,
312 ::testing::Values(
313 // When gain < |test::kLimiterMaxInputLevelDbFs|, the limiter will not
314 // saturate the signal (at any sample rate).
315 FixedDigitalTestParams(0.1f,
316 test::kLimiterMaxInputLevelDbFs - 0.01f,
317 8000,
318 false),
319 FixedDigitalTestParams(0.1,
320 test::kLimiterMaxInputLevelDbFs - 0.01f,
321 48000,
322 false),
323 // When gain > |test::kLimiterMaxInputLevelDbFs|, the limiter will
324 // saturate the signal (at any sample rate).
325 FixedDigitalTestParams(test::kLimiterMaxInputLevelDbFs + 0.01f,
326 10.f,
327 8000,
328 true),
329 FixedDigitalTestParams(test::kLimiterMaxInputLevelDbFs + 0.01f,
330 10.f,
331 48000,
332 true)));
333
334 // Checks that the gain applied at the end of a PCM samples file is close to the
335 // expected value.
TEST(GainController2,CheckGainAdaptiveDigital)336 TEST(GainController2, CheckGainAdaptiveDigital) {
337 constexpr float kExpectedGainDb = 4.3f;
338 constexpr float kToleranceDb = 0.5f;
339 GainController2 gain_controller2;
340 gain_controller2.Initialize(AudioProcessing::kSampleRate48kHz);
341 AudioProcessing::Config::GainController2 config;
342 config.fixed_digital.gain_db = 0.f;
343 config.adaptive_digital.enabled = true;
344 gain_controller2.ApplyConfig(config);
345 EXPECT_NEAR(
346 GainDbAfterProcessingFile(gain_controller2, /*max_duration_ms=*/2000),
347 kExpectedGainDb, kToleranceDb);
348 }
349
350 } // namespace test
351 } // namespace webrtc
352