Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/delay_handler.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_DELAY_HANDLER_H_

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

The functionality in DelayHandler is now moved into AecState.

+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_DELAY_HANDLER_H_
+
+#include <algorithm>
+#include <array>
+#include <vector>
+
+#include "webrtc/base/array_view.h"

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

It looks like this is not used in this header...

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

Thanks!
I removed this file now.

Done.

+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/optional.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_constants.h"
+
+namespace webrtc {
+
+// Handles the delay estimates of the echo path.
+class DelayHandler {
+ public:
+  DelayHandler();
+  ~DelayHandler();
+  // Returns the delay estimate based on the linear filter,
+  const rtc::Optional<size_t>& FilterDelay() const { return filter_delay_; }
+
+  // Returns the externally provided delay.
+  const rtc::Optional<size_t>& ExternalDelay() const { return external_delay_; }
+
+  // Updates the delay estimates.
+  void UpdateDelays(const std::vector<std::array<float, kFftLengthBy2Plus1>>&

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

... But maybe it should be used here instead of std::vector. It would make it
easier to call this function with other data than vectors (and vectors
automatically convert to ArrayView).

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

True. The advantage of doing it like this though is that it is (slightly)
cheaper. And since this is so specialized code anyway I don't think we need to
make this generic.

WDYT 

+                        filter_frequency_response,
+                    const rtc::Optional<size_t>& external_delay_samples);

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

Since this is just a single number, I think the name should be
external_delay_sample (without the s).

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

samples is the unit. But I see what you mean, this is very ambiguous. What I
intended was external_delay measured in samples, not sample of the external
delay. Do you have a good suggestion for an alternative name?

+
+ private:
+  rtc::Optional<size_t> filter_delay_;
+  rtc::Optional<size_t> external_delay_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(DelayHandler);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_DELAY_HANDLER_H_