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/*
* Copyright (c) 2018 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 "modules/audio_processing/agc2/adaptive_digital_gain_controller.h"
#include <algorithm>
#include <memory>
#include "api/audio/audio_processing.h"
#include "common_audio/include/audio_util.h"
#include "modules/audio_processing/agc2/agc2_common.h"
#include "modules/audio_processing/agc2/vector_float_frame.h"
#include "modules/audio_processing/logging/apm_data_dumper.h"
#include "rtc_base/gunit.h"
namespace webrtc {
namespace {
constexpr int kMono = 1;
constexpr int kStereo = 2;
constexpr int kFrameLen10ms8kHz = 80;
constexpr int kFrameLen10ms48kHz = 480;
constexpr float kMaxSpeechProbability = 1.0f;
// Constants used in place of estimated noise levels.
constexpr float kNoNoiseDbfs = kMinLevelDbfs;
constexpr float kWithNoiseDbfs = -20.0f;
// Number of additional frames to process in the tests to ensure that the tested
// adaptation processes have converged.
constexpr int kNumExtraFrames = 10;
constexpr float GetMaxGainChangePerFrameDb(
float max_gain_change_db_per_second) {
return max_gain_change_db_per_second * kFrameDurationMs / 1000.0f;
}
using AdaptiveDigitalConfig =
AudioProcessing::Config::GainController2::AdaptiveDigital;
constexpr AdaptiveDigitalConfig kDefaultConfig{};
// Helper to create initialized `AdaptiveDigitalGainController` objects.
struct GainApplierHelper {
GainApplierHelper(const AdaptiveDigitalConfig& config,
int adjacent_speech_frames_threshold)
: apm_data_dumper(0),
gain_applier(std::make_unique<AdaptiveDigitalGainController>(
&apm_data_dumper,
config,
adjacent_speech_frames_threshold)) {}
ApmDataDumper apm_data_dumper;
std::unique_ptr<AdaptiveDigitalGainController> gain_applier;
};
// Returns a `FrameInfo` sample to simulate noiseless speech detected with
// maximum probability and with level, headroom and limiter envelope chosen
// so that the resulting gain equals the default initial adaptive digital gain
// i.e., no gain adaptation is expected.
AdaptiveDigitalGainController::FrameInfo GetFrameInfoToNotAdapt(
const AdaptiveDigitalConfig& config) {
AdaptiveDigitalGainController::FrameInfo info;
info.speech_probability = kMaxSpeechProbability;
info.speech_level_dbfs = -config.initial_gain_db - config.headroom_db;
info.speech_level_reliable = true;
info.noise_rms_dbfs = kNoNoiseDbfs;
info.headroom_db = config.headroom_db;
info.limiter_envelope_dbfs = -2.0f;
return info;
}
TEST(GainController2AdaptiveDigitalGainControllerTest,
GainApplierShouldNotCrash) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
// Make one call with reasonable audio level values and settings.
VectorFloatFrame fake_audio(kStereo, kFrameLen10ms48kHz, 10000.0f);
helper.gain_applier->Process(GetFrameInfoToNotAdapt(kDefaultConfig),
fake_audio.view());
}
// Checks that the maximum allowed gain is applied.
TEST(GainController2AdaptiveDigitalGainControllerTest, MaxGainApplied) {
constexpr int kNumFramesToAdapt =
static_cast<int>(kDefaultConfig.max_gain_db /
GetMaxGainChangePerFrameDb(
kDefaultConfig.max_gain_change_db_per_second)) +
kNumExtraFrames;
constexpr AdaptiveDigitalConfig kConfig = AdaptiveDigitalConfig{
// Increase from the default in order to reach the maximum gain.
.max_output_noise_level_dbfs = -40.0f};
GainApplierHelper helper(kConfig, kAdjacentSpeechFramesThreshold);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kConfig);
info.speech_level_dbfs = -60.0f;
float applied_gain;
for (int i = 0; i < kNumFramesToAdapt; ++i) {
VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
helper.gain_applier->Process(info, fake_audio.view());
applied_gain = fake_audio.float_frame_view().channel(0)[0];
}
const float applied_gain_db = 20.0f * std::log10f(applied_gain);
EXPECT_NEAR(applied_gain_db, kDefaultConfig.max_gain_db, 0.1f);
}
TEST(GainController2AdaptiveDigitalGainControllerTest, GainDoesNotChangeFast) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
constexpr float initial_level_dbfs = -25.0f;
constexpr float kMaxGainChangeDbPerFrame =
GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
constexpr int kNumFramesToAdapt =
static_cast<int>(initial_level_dbfs / kMaxGainChangeDbPerFrame) +
kNumExtraFrames;
const float max_change_per_frame_linear = DbToRatio(kMaxGainChangeDbPerFrame);
float last_gain_linear = 1.f;
for (int i = 0; i < kNumFramesToAdapt; ++i) {
SCOPED_TRACE(i);
VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = initial_level_dbfs;
helper.gain_applier->Process(info, fake_audio.view());
float current_gain_linear = fake_audio.view()[0][0];
EXPECT_LE(std::abs(current_gain_linear - last_gain_linear),
max_change_per_frame_linear);
last_gain_linear = current_gain_linear;
}
// Check that the same is true when gain decreases as well.
for (int i = 0; i < kNumFramesToAdapt; ++i) {
SCOPED_TRACE(i);
VectorFloatFrame fake_audio(kMono, kFrameLen10ms8kHz, 1.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = 0.f;
helper.gain_applier->Process(info, fake_audio.view());
float current_gain_linear = fake_audio.view()[0][0];
EXPECT_LE(std::abs(current_gain_linear - last_gain_linear),
max_change_per_frame_linear);
last_gain_linear = current_gain_linear;
}
}
TEST(GainController2AdaptiveDigitalGainControllerTest, GainIsRampedInAFrame) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
constexpr float initial_level_dbfs = -25.0f;
VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = initial_level_dbfs;
helper.gain_applier->Process(info, fake_audio.view());
float maximal_difference = 0.0f;
float current_value = 1.0f * DbToRatio(kDefaultConfig.initial_gain_db);
for (const auto& x : fake_audio.view()[0]) {
const float difference = std::abs(x - current_value);
maximal_difference = std::max(maximal_difference, difference);
current_value = x;
}
const float max_change_per_frame_linear = DbToRatio(
GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second));
const float max_change_per_sample =
max_change_per_frame_linear / kFrameLen10ms48kHz;
EXPECT_LE(maximal_difference, max_change_per_sample);
}
TEST(GainController2AdaptiveDigitalGainControllerTest, NoiseLimitsGain) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
constexpr float initial_level_dbfs = -25.0f;
constexpr int num_initial_frames =
kDefaultConfig.initial_gain_db /
GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
constexpr int num_frames = 50;
ASSERT_GT(kWithNoiseDbfs, kDefaultConfig.max_output_noise_level_dbfs)
<< "kWithNoiseDbfs is too low";
for (int i = 0; i < num_initial_frames + num_frames; ++i) {
VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = initial_level_dbfs;
info.noise_rms_dbfs = kWithNoiseDbfs;
auto fake_view = fake_audio.view();
helper.gain_applier->Process(info, fake_view);
// Wait so that the adaptive gain applier has time to lower the gain.
if (i > num_initial_frames) {
const float maximal_ratio =
*std::max_element(fake_view[0].begin(), fake_view[0].end());
EXPECT_NEAR(maximal_ratio, 1.0f, 0.001f);
}
}
}
TEST(GainController2AdaptiveDigitalGainControllerTest,
CanHandlePositiveSpeechLevels) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
// Make one call with positive audio level values and settings.
VectorFloatFrame fake_audio(kStereo, kFrameLen10ms48kHz, 10000.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = 5.0f;
helper.gain_applier->Process(info, fake_audio.view());
}
TEST(GainController2AdaptiveDigitalGainControllerTest, AudioLevelLimitsGain) {
GainApplierHelper helper(kDefaultConfig, kAdjacentSpeechFramesThreshold);
constexpr float initial_level_dbfs = -25.0f;
constexpr int num_initial_frames =
kDefaultConfig.initial_gain_db /
GetMaxGainChangePerFrameDb(kDefaultConfig.max_gain_change_db_per_second);
constexpr int num_frames = 50;
ASSERT_GT(kWithNoiseDbfs, kDefaultConfig.max_output_noise_level_dbfs)
<< "kWithNoiseDbfs is too low";
for (int i = 0; i < num_initial_frames + num_frames; ++i) {
VectorFloatFrame fake_audio(kMono, kFrameLen10ms48kHz, 1.0f);
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs = initial_level_dbfs;
info.limiter_envelope_dbfs = 1.0f;
info.speech_level_reliable = false;
auto fake_view = fake_audio.view();
helper.gain_applier->Process(info, fake_view);
// Wait so that the adaptive gain applier has time to lower the gain.
if (i > num_initial_frames) {
const float maximal_ratio =
*std::max_element(fake_view[0].begin(), fake_view[0].end());
EXPECT_NEAR(maximal_ratio, 1.0f, 0.001f);
}
}
}
class AdaptiveDigitalGainControllerParametrizedTest
: public ::testing::TestWithParam<int> {
protected:
int adjacent_speech_frames_threshold() const { return GetParam(); }
};
TEST_P(AdaptiveDigitalGainControllerParametrizedTest,
DoNotIncreaseGainWithTooFewSpeechFrames) {
GainApplierHelper helper(kDefaultConfig, adjacent_speech_frames_threshold());
// Lower the speech level so that the target gain will be increased.
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs -= 12.0f;
float prev_gain = 0.0f;
for (int i = 0; i < adjacent_speech_frames_threshold(); ++i) {
SCOPED_TRACE(i);
VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
helper.gain_applier->Process(info, audio.view());
const float gain = audio.view()[0][0];
if (i > 0) {
EXPECT_EQ(prev_gain, gain); // No gain increase applied.
}
prev_gain = gain;
}
}
TEST_P(AdaptiveDigitalGainControllerParametrizedTest,
IncreaseGainWithEnoughSpeechFrames) {
GainApplierHelper helper(kDefaultConfig, adjacent_speech_frames_threshold());
// Lower the speech level so that the target gain will be increased.
AdaptiveDigitalGainController::FrameInfo info =
GetFrameInfoToNotAdapt(kDefaultConfig);
info.speech_level_dbfs -= 12.0f;
float prev_gain = 0.0f;
for (int i = 0; i < adjacent_speech_frames_threshold(); ++i) {
SCOPED_TRACE(i);
VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
helper.gain_applier->Process(info, audio.view());
prev_gain = audio.view()[0][0];
}
// Process one more speech frame.
VectorFloatFrame audio(kMono, kFrameLen10ms48kHz, 1.0f);
helper.gain_applier->Process(info, audio.view());
// An increased gain has been applied.
EXPECT_GT(audio.view()[0][0], prev_gain);
}
INSTANTIATE_TEST_SUITE_P(
GainController2,
AdaptiveDigitalGainControllerParametrizedTest,
::testing::Values(1, 7, 31, kAdjacentSpeechFramesThreshold));
} // namespace
} // namespace webrtc