Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/erl_estimator.h

+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.

[ivoc, 2017/02/10 13:52:34]

2017

[peah-webrtc, 2017/02/20 07:37:16]

Done.

+ *
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_
+
+#include <array>
+
+#include "webrtc/base/array_view.h"

[ivoc, 2017/02/10 13:52:34]

Again, no ArrayViews in this file, but maybe there should be, WDYT?

[peah-webrtc, 2017/02/20 07:37:16]

Not in this case, since we know what the incoming sizes will be and not using
ArrayViews will allow us to rely on the compiler for verifying the correctness
of the input.

[ivoc, 2017/02/21 17:26:01]

Acknowledged.

[peah-webrtc, 2017/02/21 23:00:39]

Acknowledged.

+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/optional.h"

[ivoc, 2017/02/10 13:52:34]

Can be removed.

[peah-webrtc, 2017/02/20 07:37:16]

Done.

+#include "webrtc/modules/audio_processing/aec3/aec3_constants.h"
+
+namespace webrtc {
+
+// Estimates the echo return loss based on the signal spectra.
+class ErlEstimator {
+ public:
+  ErlEstimator();
+  ~ErlEstimator();
+
+  // Updates the ERL estimate.
+  void Update(const std::array<float, kFftLengthBy2Plus1>& render_spectrum,
+              const std::array<float, kFftLengthBy2Plus1>& capture_spectrum);
+
+  // Returns the most recent ERL estimate.
+  const std::array<float, kFftLengthBy2Plus1>& Erl() const { return erl_; }
+
+ private:
+  std::array<float, kFftLengthBy2Plus1> erl_;
+  std::array<int, kFftLengthBy2Plus1 - 2> hold_counters_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(ErlEstimator);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_