Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h

Index: webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h
diff --git a/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..c93edc45963e37480562b840e05c54fb1f79e094
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h
@@ -0,0 +1,113 @@
+/*
+ *  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_ADAPTIVE_FIR_FILTER_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_ADAPTIVE_FIR_FILTER_H_
+
+#include <array>
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_fft.h"
+#include "webrtc/modules/audio_processing/aec3/fft_buffer.h"
+#include "webrtc/modules/audio_processing/aec3/fft_data.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"

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

Include can be in the .cc, if you add a forward declaration.

[peah-webrtc, 2017/02/21 23:00:40]

No, that is not possible since the DumpFilter method uses members of that class.

[ivoc, 2017/02/22 17:08:12]

Ah, I missed that, sorry.

[peah-webrtc, 2017/02/22 23:51:36]

Np.

+
+namespace webrtc {
+
+// Adapts the filter partitions.
+void AdaptPartitions(const FftBuffer& X_buffer,
+                     const FftData& G,
+                     rtc::ArrayView<FftData> H);
+#if defined(WEBRTC_ARCH_X86_FAMILY)

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

I think a possibly better option would be to use an #if/#else construction
inside the regular AdaptPartitions function, to use the SSE implementation when
the flag is set. That way the caller doesn't have to know or care if SSE is
available or not. The same applies for the other SSE function below.

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

That makes sense. I don't think it works though.

As it is now SSE2 instructions can be used if
1) WEBRTC_ARCH_X86_FAMILY is defined.
and
2) WebRtc_GetCPUInfo(kSSE2) does not return 0.

In order to do what is proposed, 2) needs to be called at each called to the
optimised method and I don't think that is a good thing.

A second advantage of having the optimized methods exposed in the header, and
separate from their unoptimised counterparts, is that the optimised code may be
benchmarked against the unoptimized code in unit tests. That would not be
possible if the SSE implementations were implemented inside the same function as
the unoptimized code.

In order to make the testing simple, and to make the selection of the optimized
code for running, this was the best approach I came up with. If you find a
better way, I'd be delighted though! (but due to 2, the approach suggested above
won't work).
WDYT?

[ivoc, 2017/02/22 17:08:12]

Ok, that's a good point. Let's keep it like this.

[peah-webrtc, 2017/02/22 23:51:36]

Acknowledged.

+void AdaptPartitions_SSE2(const FftBuffer& X_buffer,
+                          const FftData& G,
+                          rtc::ArrayView<FftData> H);
+#endif
+
+// Produces the filter output.
+void ApplyFilter(const FftBuffer& X_buffer,
+                 rtc::ArrayView<const FftData> H,
+                 FftData* S);
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+void ApplyFilter_SSE2(const FftBuffer& X_buffer,
+                      rtc::ArrayView<const FftData> H,
+                      FftData* S);
+#endif
+
+// Provides a frequency domain adaptive filter functionality.
+class AdaptiveFirFilter {
+ public:
+  AdaptiveFirFilter(size_t size_partitions,
+                    bool use_filter_statistics,
+                    Aec3Optimization optimization,
+                    ApmDataDumper* data_dumper);
+
+  ~AdaptiveFirFilter();
+
+  // Produces the output of the filter.
+  void Filter(const FftBuffer& X_buffer, FftData* S) const;
+
+  // Adapts the filter.
+  void Adapt(const FftBuffer& X_buffer, const FftData& G);
+
+  // Receives reports that known echo path changes have occured and takes asjust

[hlundin-webrtc, 2017/02/21 09:40:03]

"takes asjust"?

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

Done.

+  // the filter adaptation accordingly.
+  void HandleEchoPathChange();
+
+  // Returns the filter size.
+  size_t SizePartitions() const { return H_.size(); }
+
+  // Returns the filter based echo return loss. This method can only be used if
+  // the usage of filter statistics have been specified during the creation of

[hlundin-webrtc, 2017/02/21 09:40:03]

have -> has ('usage' is singular (or possibly uncountable))

[peah-webrtc, 2017/02/21 23:00:40]

Done.

+  // the adaptive filter.
+  const std::array<float, kFftLengthBy2Plus1>& Erl() const {
+    RTC_DCHECK(erl_) << "The filter must be created with use_filter_statistics "
+                        "set to true in order to be able to call retrieve the "
+                        "ERL.";
+    return *erl_;
+  }
+
+  // Returns the frequency responses for the filter partitions. This method can
+  // only be used if the usage of filter statistics have been specified during

[hlundin-webrtc, 2017/02/21 09:40:03]

have -> has

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

Done.

+  // the creation of the adaptive filter.
+  const std::vector<std::array<float, kFftLengthBy2Plus1>>&
+  FilterFrequencyResponse() const {
+    RTC_DCHECK(H2_) << "The filter must be created with use_filter_statistics "
+                       "set to true in order to be able to call retrieve the "
+                       "filter frequency responde.";
+    return *H2_;
+  }
+
+  void DumpFilter(const char* name) {
+    for (auto& H : H_) {
+      data_dumper_->DumpRaw(name, H.re);
+      data_dumper_->DumpRaw(name, H.im);
+    }
+  }
+
+ private:
+  ApmDataDumper* const data_dumper_;
+  const Aec3Fft fft_;
+  const Aec3Optimization optimization_;
+  std::vector<FftData> H_;
+  std::unique_ptr<std::vector<std::array<float, kFftLengthBy2Plus1>>> H2_;
+  std::unique_ptr<std::array<float, kFftLengthBy2Plus1>> erl_;
+  size_t partition_to_constrain_ = 0;
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(AdaptiveFirFilter);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_ADAPTIVE_FIR_FILTER_H_