Surface the noise estimate of the NS to be used by other components

webrtc/modules/audio_processing/noise_suppression_impl.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 154 matching lines @@
   if (!suppressors_.empty()) {
     probability_average /= suppressors_.size();
   }
   return probability_average;
 #elif defined(WEBRTC_NS_FIXED)
   // TODO(peah): Returning error code as a float! Remove this.
   // Currently not available for the fixed point implementation.
   return AudioProcessing::kUnsupportedFunctionError;
 #endif
 }
+
+std::vector<float> NoiseSuppressionImpl::noise_estimate() {

[hlundin-webrtc, 2016/02/09 15:33:51]

Rename function to NoiseEstimate, to reflect the fact that it is not a simple
getter; some calculations will happen that may lead to performance impact.

[aluebs-webrtc, 2016/02/09 17:48:49]

Good idea. Done.

+  rtc::CritScope cs(crit_);
+  std::vector<float> noise_estimate;
+#if defined(WEBRTC_NS_FLOAT)
+  noise_estimate.assign(WebRtcNs_num_freq(), 0.f);
+  for (auto& suppressor : suppressors_) {
+    const float* noise = WebRtcNs_noise_estimate(suppressor->state());
+    for (size_t i = 0; i < noise_estimate.size(); ++i) {
+      noise_estimate[i] += noise[i] / suppressors_.size();
+    }
+  }
+#elif defined(WEBRTC_NS_FIXED)
+  const float kNormalizationFactor = 1.f / (1 << 17);
+  noise_estimate.assign(WebRtcNsx_num_freq(), 0.f);
+  for (auto& suppressor : suppressors_) {
+    const uint32_t* noise = WebRtcNsx_noise_estimate(suppressor->state());
+    for (size_t i = 0; i < noise_estimate.size(); ++i) {
+      noise_estimate[i] += kNormalizationFactor *
+          static_cast<float>(noise[i]) / suppressors_.size();
+    }
+  }
+#endif
+  return noise_estimate;
+}
+
 }  // namespace webrtc