AGC2 AdaptiveModeLevelEstimator: cache last level estimate

`AdaptiveModeLevelEstimator::last_level_dbfs_` doesn't need to be optional.

Note: this CL breaks the chain of 3 CLs titled
"AGC2 AdaptiveModeLevelEstimator min consecutive speech frames".

Bug: webrtc:7494
Change-Id: Id5b409ca5cb5f11ed132c861b7995b9721e167bb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/185809
Reviewed-by: Minyue Li <minyue@webrtc.org>
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32237}

modules/audio_processing/agc2/adaptive_agc.cc

@@ -53,7 +53,7 @@ void AdaptiveAgc::Process(AudioFrameView<float> float_frame,
 
   speech_level_estimator_.Update(signal_with_levels.vad_result);
 
-  signal_with_levels.input_level_dbfs = speech_level_estimator_.GetLevelDbfs();
+  signal_with_levels.input_level_dbfs = speech_level_estimator_.level_dbfs();
 
   signal_with_levels.input_noise_level_dbfs =
       noise_level_estimator_.Analyze(float_frame);

modules/audio_processing/agc2/adaptive_mode_level_estimator.cc

@@ -16,6 +16,38 @@
 #include "rtc_base/numerics/safe_minmax.h"
 
 namespace webrtc {
+namespace {
+
+using LevelEstimatorType =
+    AudioProcessing::Config::GainController2::LevelEstimator;
+
+// Combines a level estimation with the saturation protector margins.
+float ComputeLevelEstimateDbfs(float level_estimate_dbfs,
+                               bool use_saturation_protector,
+                               float saturation_margin_db,
+                               float extra_saturation_margin_db) {
+  return rtc::SafeClamp<float>(
+      level_estimate_dbfs +
+          (use_saturation_protector
+               ? (saturation_margin_db + extra_saturation_margin_db)
+               : 0.f),
+      -90.f, 30.f);
+}
+
+// Returns the level of given type from `vad_level`.
+float GetLevel(const VadLevelAnalyzer::Result& vad_level,
+               LevelEstimatorType type) {
+  switch (type) {
+    case LevelEstimatorType::kRms:
+      return vad_level.rms_dbfs;
+      break;
+    case LevelEstimatorType::kPeak:
+      return vad_level.peak_dbfs;
+      break;
+  }
+}
+
+}  // namespace
 
 float AdaptiveModeLevelEstimator::State::Ratio::GetRatio() const {
   RTC_DCHECK_NE(denominator, 0.f);
@@ -53,7 +85,10 @@ AdaptiveModeLevelEstimator::AdaptiveModeLevelEstimator(
       use_saturation_protector_(use_saturation_protector),
       initial_saturation_margin_db_(initial_saturation_margin_db),
       extra_saturation_margin_db_(extra_saturation_margin_db),
-      last_level_dbfs_(absl::nullopt) {
+      level_dbfs_(ComputeLevelEstimateDbfs(kInitialSpeechLevelEstimateDbfs,
+                                           use_saturation_protector_,
+                                           initial_saturation_margin_db_,
+                                           extra_saturation_margin_db_)) {
   Reset();
 }
 
@@ -78,49 +113,30 @@ void AdaptiveModeLevelEstimator::Update(
     state_.time_to_full_buffer_ms -= kFrameDurationMs;
   }
 
-  // Read level estimation.
-  float level_dbfs = 0.f;
-  using LevelEstimatorType =
-      AudioProcessing::Config::GainController2::LevelEstimator;
-  switch (level_estimator_type_) {
-    case LevelEstimatorType::kRms:
-      level_dbfs = vad_level.rms_dbfs;
-      break;
-    case LevelEstimatorType::kPeak:
-      level_dbfs = vad_level.peak_dbfs;
-      break;
-  }
-
   // Update level estimation (average level weighted by speech probability).
   RTC_DCHECK_GT(vad_level.speech_probability, 0.f);
   const float leak_factor = buffer_is_full ? kFullBufferLeakFactor : 1.f;
-  state_.level_dbfs.numerator = state_.level_dbfs.numerator * leak_factor +
+  state_.level_dbfs.numerator =
-                                level_dbfs * vad_level.speech_probability;
+      state_.level_dbfs.numerator * leak_factor +
+      GetLevel(vad_level, level_estimator_type_) * vad_level.speech_probability;
   state_.level_dbfs.denominator = state_.level_dbfs.denominator * leak_factor +
                                   vad_level.speech_probability;
 
-  // Cache level estimation.
+  const float level_dbfs = state_.level_dbfs.GetRatio();
-  last_level_dbfs_ = state_.level_dbfs.GetRatio();
 
   if (use_saturation_protector_) {
-    UpdateSaturationProtectorState(
+    UpdateSaturationProtectorState(vad_level.peak_dbfs, level_dbfs,
-        /*speech_peak_dbfs=*/vad_level.peak_dbfs,
+                                   state_.saturation_protector);
-        /*speech_level_dbfs=*/last_level_dbfs_.value(),
-        state_.saturation_protector);
   }
 
+  // Cache level estimation.
+  level_dbfs_ = ComputeLevelEstimateDbfs(level_dbfs, use_saturation_protector_,
+                                         state_.saturation_protector.margin_db,
+                                         extra_saturation_margin_db_);
+
   DebugDumpEstimate();
 }
 
-float AdaptiveModeLevelEstimator::GetLevelDbfs() const {
-  float level_dbfs = last_level_dbfs_.value_or(kInitialSpeechLevelEstimateDbfs);
-  if (use_saturation_protector_) {
-    level_dbfs += state_.saturation_protector.margin_db;
-    level_dbfs += extra_saturation_margin_db_;
-  }
-  return rtc::SafeClamp<float>(level_dbfs, -90.f, 30.f);
-}
-
 bool AdaptiveModeLevelEstimator::IsConfident() const {
   // Returns true if enough speech frames have been observed.
   return state_.time_to_full_buffer_ms == 0;
@@ -128,7 +144,9 @@ bool AdaptiveModeLevelEstimator::IsConfident() const {
 
 void AdaptiveModeLevelEstimator::Reset() {
   ResetState(state_);
-  last_level_dbfs_ = absl::nullopt;
+  level_dbfs_ = ComputeLevelEstimateDbfs(
+      kInitialSpeechLevelEstimateDbfs, use_saturation_protector_,
+      initial_saturation_margin_db_, extra_saturation_margin_db_);
 }
 
 void AdaptiveModeLevelEstimator::ResetState(State& state) {
@@ -141,8 +159,7 @@ void AdaptiveModeLevelEstimator::ResetState(State& state) {
 
 void AdaptiveModeLevelEstimator::DebugDumpEstimate() {
   if (apm_data_dumper_) {
-    apm_data_dumper_->DumpRaw("agc2_adaptive_level_estimate_dbfs",
+    apm_data_dumper_->DumpRaw("agc2_adaptive_level_estimate_dbfs", level_dbfs_);
-                              GetLevelDbfs());
     apm_data_dumper_->DumpRaw("agc2_adaptive_saturation_margin_db",
                               state_.saturation_protector.margin_db);
   }

modules/audio_processing/agc2/adaptive_mode_level_estimator.h

@@ -13,7 +13,6 @@
 
 #include <stddef.h>
 
-#include "absl/types/optional.h"
 #include "modules/audio_processing/agc2/agc2_common.h"
 #include "modules/audio_processing/agc2/saturation_protector.h"
 #include "modules/audio_processing/agc2/vad_with_level.h"
@@ -46,7 +45,7 @@ class AdaptiveModeLevelEstimator {
   // Updates the level estimation.
   void Update(const VadLevelAnalyzer::Result& vad_data);
   // Returns the estimated speech plus noise level.
-  float GetLevelDbfs() const;
+  float level_dbfs() const { return level_dbfs_; }
   // Returns true if the estimator is confident on its current estimate.
   bool IsConfident() const;
 
@@ -77,7 +76,7 @@ class AdaptiveModeLevelEstimator {
   const float extra_saturation_margin_db_;
   // TODO(crbug.com/webrtc/7494): Add temporary state.
   State state_;
-  absl::optional<float> last_level_dbfs_;
+  float level_dbfs_;
 };
 
 }  // namespace webrtc

modules/audio_processing/agc2/adaptive_mode_level_estimator_agc.cc

@@ -49,7 +49,7 @@ bool AdaptiveModeLevelEstimatorAgc::GetRmsErrorDb(int* error) {
     return false;
   }
   *error =
-      std::floor(target_level_dbfs() - level_estimator_.GetLevelDbfs() + 0.5f);
+      std::floor(target_level_dbfs() - level_estimator_.level_dbfs() + 0.5f);
   time_in_ms_since_last_estimate_ = 0;
   return true;
 }

modules/audio_processing/agc2/adaptive_mode_level_estimator_unittest.cc

@@ -53,7 +53,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator,
   VadLevelAnalyzer::Result vad_level{kMaxSpeechProbability, /*rms_dbfs=*/-20.f,
                                      /*peak_dbfs=*/-10.f};
   level_estimator.estimator->Update(vad_level);
-  static_cast<void>(level_estimator.estimator->GetLevelDbfs());
+  static_cast<void>(level_estimator.estimator->level_dbfs());
 }
 
 TEST(AutomaticGainController2AdaptiveModeLevelEstimator, LevelShouldStabilize) {
@@ -68,7 +68,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator, LevelShouldStabilize) {
                      *level_estimator.estimator);
 
   EXPECT_NEAR(
-      level_estimator.estimator->GetLevelDbfs() - kExtraSaturationMarginDb,
+      level_estimator.estimator->level_dbfs() - kExtraSaturationMarginDb,
       kSpeechPeakDbfs, 0.1f);
 }
 
@@ -95,7 +95,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator,
 
   // Level should not have changed.
   EXPECT_NEAR(
-      level_estimator.estimator->GetLevelDbfs() - kExtraSaturationMarginDb,
+      level_estimator.estimator->level_dbfs() - kExtraSaturationMarginDb,
       kSpeechRmsDbfs, 0.1f);
 }
 
@@ -126,7 +126,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator, TimeToAdapt) {
           /*peak_dbfs=*/kDifferentSpeechRmsDbfs},
       *level_estimator.estimator);
   EXPECT_GT(std::abs(kDifferentSpeechRmsDbfs -
-                     level_estimator.estimator->GetLevelDbfs()),
+                     level_estimator.estimator->level_dbfs()),
             kMaxDifferenceDb);
 
   // Run for some more time. Afterwards, we should have adapted.
@@ -138,7 +138,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator, TimeToAdapt) {
           /*peak_dbfs=*/kDifferentSpeechRmsDbfs},
       *level_estimator.estimator);
   EXPECT_NEAR(
-      level_estimator.estimator->GetLevelDbfs() - kExtraSaturationMarginDb,
+      level_estimator.estimator->level_dbfs() - kExtraSaturationMarginDb,
       kDifferentSpeechRmsDbfs, kMaxDifferenceDb * 0.5f);
 }
 
@@ -173,7 +173,7 @@ TEST(AutomaticGainController2AdaptiveModeLevelEstimator,
   const float kMaxDifferenceDb =
       0.1f * std::abs(kDifferentSpeechRmsDbfs - kInitialSpeechRmsDbfs);
   EXPECT_LT(std::abs(kDifferentSpeechRmsDbfs -
-                     (level_estimator.estimator->GetLevelDbfs() -
+                     (level_estimator.estimator->level_dbfs() -
                       kExtraSaturationMarginDb)),
             kMaxDifferenceDb);
 }