AdaptiveDigitalGainController: Add method GetSpeechLevelDbfsIfConfident

Bug: webrtc:7494
Change-Id: I18d8ee4e50f6fd901f29e4591ff12759018d070d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/277381
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Commit-Queue: Hanna Silen <silen@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38303}

modules/audio_processing/agc2/adaptive_digital_gain_controller.cc

@@ -105,4 +105,11 @@ void AdaptiveDigitalGainController::HandleInputGainChange() {
   saturation_protector_->Reset();
 }
 
+absl::optional<float>
+AdaptiveDigitalGainController::GetSpeechLevelDbfsIfConfident() const {
+  return speech_level_estimator_.IsConfident()
+             ? absl::optional<float>(speech_level_estimator_.level_dbfs())
+             : absl::nullopt;
+}
+
 }  // namespace webrtc

modules/audio_processing/agc2/adaptive_digital_gain_controller.h

@@ -13,6 +13,7 @@
 
 #include <memory>
 
+#include "absl/types/optional.h"
 #include "modules/audio_processing/agc2/adaptive_digital_gain_applier.h"
 #include "modules/audio_processing/agc2/adaptive_mode_level_estimator.h"
 #include "modules/audio_processing/agc2/noise_level_estimator.h"
@@ -50,6 +51,10 @@ class AdaptiveDigitalGainController {
   // Handles a gain change applied to the input signal (e.g., analog gain).
   void HandleInputGainChange();
 
+  // Returns the most recent speech level (dBFs) if the estimator is confident.
+  // Otherwise returns absl::nullopt.
+  absl::optional<float> GetSpeechLevelDbfsIfConfident() const;
+
  private:
   AdaptiveModeLevelEstimator speech_level_estimator_;
   AdaptiveDigitalGainApplier gain_controller_;