Added first layer of the echo canceller 3 functionality

webrtc/modules/audio_processing/aec3/block_processor.h

Index: webrtc/modules/audio_processing/aec3/block_processor.h
diff --git a/webrtc/modules/audio_processing/aec3/block_processor.h b/webrtc/modules/audio_processing/aec3/block_processor.h
new file mode 100644
index 0000000000000000000000000000000000000000..062b7e0468b8ccecde659c432551c612463024dd
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/block_processor.h
@@ -0,0 +1,69 @@
+/*
+ *  Copyright (c) 2016 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_BLOCK_PROCESSOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_BLOCK_PROCESSOR_H_
+
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
+
+namespace webrtc {
+
+// BlockProcessor interface.

[aleloi, 2016/12/20 15:55:35]

I think this comment can be removed or changed to describe what a BlockProcessor
is.

[peah-webrtc, 2016/12/21 23:13:50]

Done.

+class BlockProcessor {
+ public:
+  static BlockProcessor* Create(int sample_rate_hz, size_t num_bands);
+  virtual ~BlockProcessor() {}

[aleloi, 2016/12/20 15:55:35]

= default.

[peah-webrtc, 2016/12/21 23:13:50]

Done.

+
+  // Processes a block of capture data.
+  virtual void ProcessCapture(
+      bool known_echo_path_change,
+      bool saturated_microphone_signal,
+      std::vector<std::vector<float>>* capture_block) = 0;
+
+  // Buffers a block of render data supplied by a FrameBlocker object.
+  virtual bool BufferRender(std::vector<std::vector<float>>* block) = 0;
+
+  // Reports whether echo leakage has been detected in the echo canceller
+  // output.
+  virtual void ReportEchoLeakage(bool leakage_detected) = 0;
+};
+
+// Class for performing echo cancellation on 64 sample blocks of audio data.
+// Implements the BlockProcessor interface.
+class BlockProcessorImpl : public BlockProcessor {

[hlundin-webrtc, 2016/12/20 15:10:35]

final

[hlundin-webrtc, 2016/12/20 15:10:35]

Since you have a Create method in the interface class, and the method is
implemented in the .cc file, you can actually move also the declaration of
BlockProcessorImpl to the .cc file. This is how it is done in for
audio_coding_module.cc.

[peah-webrtc, 2016/12/21 23:13:50]

Done.

[peah-webrtc, 2016/12/21 23:13:50]

Awesome suggestion! 

Done.

+ public:
+  BlockProcessorImpl(int sample_rate_hz, size_t num_bands);
+  ~BlockProcessorImpl() override;
+
+  // Processes a block of capture data.

[hlundin-webrtc, 2016/12/20 15:10:35]

You can skip all the duplicated method comments. They will only diverge over
time.

[peah-webrtc, 2016/12/21 23:13:50]

Done.

+  void ProcessCapture(bool known_echo_path_change,
+                      bool saturated_microphone_signal,
+                      std::vector<std::vector<float>>* capture_block) override;
+
+  // Buffers a block of render data supplied by a FrameBlocker object.
+  bool BufferRender(std::vector<std::vector<float>>* block) override;
+
+  // Reports whether echo leakage has been detected in the echo canceller
+  // output.
+  void ReportEchoLeakage(bool leakage_detected) override;
+
+ private:
+  static int instance_count_;
+  std::unique_ptr<ApmDataDumper> data_dumper_;
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(BlockProcessorImpl);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_BLOCK_PROCESSOR_H_