Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/comfort_noise_generator.h

Index: webrtc/modules/audio_processing/aec3/comfort_noise_generator.h
diff --git a/webrtc/modules/audio_processing/aec3/comfort_noise_generator.h b/webrtc/modules/audio_processing/aec3/comfort_noise_generator.h
new file mode 100644
index 0000000000000000000000000000000000000000..1a9d75d60ae283e69c45484bbdf1495b9dae45d8
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/comfort_noise_generator.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright (c) 2017 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
+
+#include <stdio.h>

[ivoc, 2017/02/10 13:52:33]

Is this needed? For the uin32_t you could use stdint.h

[peah-webrtc, 2017/02/20 07:37:15]

Done.

+#include <memory>
+#include <vector>

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

Can be removed

[peah-webrtc, 2017/02/20 07:37:15]

Done.

+
+#include "webrtc/base/array_view.h"

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

Looks like ArrayView is not used in this header, but perhaps it should be used
on the interfaces (instead of array), for more flexibility. WDYT?

[peah-webrtc, 2017/02/20 07:37:15]

I prefer array as it will give a compile-time warning about the size which means
that DCHECKS on the size is not needed. Everything is anyway so tightly coupled
with the sizes so I don't the flexibility achieved by array-view could be used
anyway.

WDYT?

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

Ok, sounds good.

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

Acknowledged.

+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_constants.h"
+#include "webrtc/modules/audio_processing/aec3/fft_data.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"

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

Is this used?

[peah-webrtc, 2017/02/20 07:37:15]

Done.

+
+namespace webrtc {
+
+// Generates the comfort noise.
+class ComfortNoiseGenerator {
+ public:
+  ComfortNoiseGenerator();
+  ~ComfortNoiseGenerator();
+
+  // Computes the comfort noise.
+  void Compute(const std::array<float, kFftLengthBy2Plus1>& capture_spectrum,

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

#include <array> is missing.

[peah-webrtc, 2017/02/20 07:37:15]

Done.

+               FftData* lower_band_noise,
+               FftData* upper_band_noise);
+
+  // Returns the estimate of the background noise spectrum.
+  const std::array<float, kFftLengthBy2Plus1>& NoiseSpectrum() const {
+    return N2_;
+  }
+
+ private:
+  uint32_t seed_;
+  std::unique_ptr<std::array<float, kFftLengthBy2Plus1>> N2_initial_;
+  std::array<float, kFftLengthBy2Plus1> Y2_smoothed_;
+  std::array<float, kFftLengthBy2Plus1> N2_;
+  int N2_counter_ = 0;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(ComfortNoiseGenerator);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_