Reland "Revert "audio_processing/aec: make delay estimator aware of starving farend buffer""

webrtc/modules/audio_processing/aec/echo_cancellation.c

 /*
  *  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 217 matching lines @@
   aecpc->delayCtr = 0;
   aecpc->sampFactor = (aecpc->scSampFreq * 1.0f) / aecpc->splitSampFreq;
   // Sampling frequency multiplier (SWB is processed as 160 frame size).
   aecpc->rate_factor = aecpc->splitSampFreq / 8000;
 
   aecpc->sum = 0;
   aecpc->counter = 0;
   aecpc->checkBuffSize = 1;
   aecpc->firstVal = 0;
 
-  aecpc->startup_phase = WebRtcAec_reported_delay_enabled(aecpc->aec);
+  // We skip the startup_phase completely (setting to 0) if DA-AEC is enabled,
+  // but not extended_filter mode.
+  aecpc->startup_phase = WebRtcAec_extended_filter_enabled(aecpc->aec) ||
+      WebRtcAec_reported_delay_enabled(aecpc->aec);
   aecpc->bufSizeStart = 0;
   aecpc->checkBufSizeCtr = 0;
   aecpc->msInSndCardBuf = 0;
   aecpc->filtDelay = -1;  // -1 indicates an initialized state.
   aecpc->timeForDelayChange = 0;
   aecpc->knownDelay = 0;
   aecpc->lastDelayDiff = 0;
 
   aecpc->skewFrCtr = 0;
   aecpc->resample = kAecFalse;
@@ skipping 462 matching lines @@
         // to the buffer and no delay compensation nor AEC processing
         // has been done.
         WebRtcAec_MoveFarReadPtr(aecpc->aec, overhead_elements);
 
         // Enable the AEC
         aecpc->startup_phase = 0;
       }
     }
   } else {
     // AEC is enabled.
-    if (WebRtcAec_reported_delay_enabled(aecpc->aec)) {
-      EstBufDelayNormal(aecpc);
-    }
+    EstBufDelayNormal(aecpc);
 
     // Call the AEC.
     // TODO(bjornv): Re-structure such that we don't have to pass
     // |aecpc->knownDelay| as input. Change name to something like
     // |system_buffer_diff|.
     WebRtcAec_ProcessFrames(aecpc->aec,
                             nearend,
                             num_bands,
                             nrOfSamples,
                             aecpc->knownDelay,
@@ skipping 41 matching lines @@
     }
     return;
   }
   if (self->startup_phase) {
     // In the extended mode, there isn't a startup "phase", just a special
     // action on the first frame. In the trusted delay case, we'll take the
     // current reported delay, unless it's less then our conservative
     // measurement.
     int startup_size_ms =
         reported_delay_ms < kFixedDelayMs ? kFixedDelayMs : reported_delay_ms;
+#if defined(WEBRTC_ANDROID)
     int target_delay = startup_size_ms * self->rate_factor * 8;
-#if !defined(WEBRTC_ANDROID)
+#else
     // To avoid putting the AEC in a non-causal state we're being slightly
     // conservative and scale by 2. On Android we use a fixed delay and
     // therefore there is no need to scale the target_delay.
-    target_delay /= 2;
+    int target_delay = startup_size_ms * self->rate_factor * 8 / 2;
 #endif
     int overhead_elements =
         (WebRtcAec_system_delay(self->aec) - target_delay) / PART_LEN;
     WebRtcAec_MoveFarReadPtr(self->aec, overhead_elements);
     self->startup_phase = 0;
   }
 
-  if (WebRtcAec_reported_delay_enabled(self->aec)) {
-    EstBufDelayExtended(self);
-  }
+  EstBufDelayExtended(self);
 
   {
     // |delay_diff_offset| gives us the option to manually rewind the delay on
     // very low delay platforms which can't be expressed purely through
     // |reported_delay_ms|.
     const int adjusted_known_delay =
         WEBRTC_SPL_MAX(0, self->knownDelay + delay_diff_offset);
 
     WebRtcAec_ProcessFrames(self->aec,
                             near,
@@ skipping 103 matching lines @@
     }
   } else {
     self->timeForDelayChange = 0;
   }
   self->lastDelayDiff = delay_difference;
 
   if (self->timeForDelayChange > 25) {
     self->knownDelay = WEBRTC_SPL_MAX((int)self->filtDelay - 256, 0);
   }
 }