Re-land r9378 "Rename APM Config DelayCorrection to ExtendedFilter"

webrtc/modules/audio_processing/include/audio_processing.h

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 19 matching lines @@
 class Beamformer;
 
 class EchoCancellation;
 class EchoControlMobile;
 class GainControl;
 class HighPassFilter;
 class LevelEstimator;
 class NoiseSuppression;
 class VoiceDetection;
 
-// Use to enable the delay correction feature. This now engages an extended
-// filter mode in the AEC, along with robustness measures around the reported
-// system delays. It comes with a significant increase in AEC complexity, but is
-// much more robust to unreliable reported delays.
+// Use to enable the extended filter mode in the AEC, along with robustness
+// measures around the reported system delays. It comes with a significant
+// increase in AEC complexity, but is much more robust to unreliable reported
+// delays.
 //
 // Detailed changes to the algorithm:
 // - The filter length is changed from 48 to 128 ms. This comes with tuning of
 //   several parameters: i) filter adaptation stepsize and error threshold;
 //   ii) non-linear processing smoothing and overdrive.
 // - Option to ignore the reported delays on platforms which we deem
 //   sufficiently unreliable. See WEBRTC_UNTRUSTED_DELAY in echo_cancellation.c.
 // - Faster startup times by removing the excessive "startup phase" processing
 //   of reported delays.
 // - Much more conservative adjustments to the far-end read pointer. We smooth
 //   the delay difference more heavily, and back off from the difference more.
 //   Adjustments force a readaptation of the filter, so they should be avoided
 //   except when really necessary.
+// TODO(henrik.lundin): Remove DelayCorrection once ExtendedFilter has
+// propagated through to all channels
+// (https://code.google.com/p/webrtc/issues/detail?id=4696).
 struct DelayCorrection {
   DelayCorrection() : enabled(false) {}
   explicit DelayCorrection(bool enabled) : enabled(enabled) {}
   bool enabled;
 };
+struct ExtendedFilter {
+  ExtendedFilter() : enabled(false) {}
+  explicit ExtendedFilter(bool enabled) : enabled(enabled) {}
+  bool enabled;
+};
 
 // Use to disable the reported system delays. By disabling the reported system
 // delays the echo cancellation algorithm assumes the process and reverse
 // streams to be aligned. This configuration only applies to EchoCancellation
 // and not EchoControlMobile and is set with AudioProcessing::SetExtraOptions().
 // Note that by disabling reported system delays the EchoCancellation may
 // regress in performance.
 struct ReportedDelay {
   ReportedDelay() : enabled(true) {}
   explicit ReportedDelay(bool enabled) : enabled(enabled) {}
@@ skipping 710 matching lines @@
   // This does not impact the size of frames passed to |ProcessStream()|.
   virtual int set_frame_size_ms(int size) = 0;
   virtual int frame_size_ms() const = 0;
 
  protected:
   virtual ~VoiceDetection() {}
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_INCLUDE_AUDIO_PROCESSING_H_