Convert IntelligibilityEnhancer to multi-threaded mode

webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h

Index: webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h
index 3b46d16afeff4e6296ab61d8bc80f57435ab16ea..c8576614737810f3bd4183130c9fd3a2df7101bd 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h
@@ -17,7 +17,9 @@
 
 #include "webrtc/common_audio/lapped_transform.h"
 #include "webrtc/common_audio/channel_buffer.h"
+#include "webrtc/common_audio/swap_queue.h"
 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h"
+#include "webrtc/modules/audio_processing/processing_component.h"
 #include "webrtc/modules/audio_processing/vad/voice_activity_detector.h"
 
 namespace webrtc {
@@ -29,7 +31,9 @@ namespace webrtc {
 // http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6882788
 class IntelligibilityEnhancer : public LappedTransform::Callback {
  public:
-  IntelligibilityEnhancer(int sample_rate_hz, size_t num_render_channels);
+  IntelligibilityEnhancer(int sample_rate_hz,
+                          size_t num_render_channels,
+                          size_t num_noise_bins);
 
   // Sets the capture noise magnitude spectrum estimate.
   void SetCaptureNoiseEstimate(std::vector<float> noise);
@@ -72,15 +76,17 @@ class IntelligibilityEnhancer : public LappedTransform::Callback {
   // Returns true if the audio is speech.
   bool IsSpeech(const float* audio);
 
+  static const size_t kMaxNumNoiseEstimatesToBuffer = 5;
+
   const size_t freqs_;         // Num frequencies in frequency domain.
+  const size_t num_noise_bins_;
   const size_t chunk_length_;  // Chunk size in samples.
   const size_t bank_size_;     // Num ERB filters.
   const int sample_rate_hz_;
   const size_t num_render_channels_;
 
   intelligibility::PowerEstimator<std::complex<float>> clear_power_estimator_;
-  std::unique_ptr<intelligibility::PowerEstimator<float>>
-      noise_power_estimator_;
+  intelligibility::PowerEstimator<float> noise_power_estimator_;
   std::vector<float> filtered_clear_pow_;
   std::vector<float> filtered_noise_pow_;
   std::vector<float> center_freqs_;
@@ -97,6 +103,10 @@ class IntelligibilityEnhancer : public LappedTransform::Callback {
   std::vector<int16_t> audio_s16_;
   size_t chunks_since_voice_;
   bool is_speech_;
+
+  std::vector<float> noise_estimation_buffer_;
+  SwapQueue<std::vector<float>, RenderQueueItemVerifier<float>>
+      noise_estimation_queue_;
 };
 
 }  // namespace webrtc