Allow extracting the linear AEC output

This CL enables extracting the linear AEC output,
allowing for more straightforward
testing/development.

Bug: b/140823178
Change-Id: I14f7934008d87066b35500466cb6e6d96f811688
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/153672
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29789}
diff --git a/modules/audio_processing/aec3/aec3_common.h b/modules/audio_processing/aec3/aec3_common.h
index bf554e3..d778e50 100644
--- a/modules/audio_processing/aec3/aec3_common.h
+++ b/modules/audio_processing/aec3/aec3_common.h
@@ -42,7 +42,8 @@
 constexpr int kRenderTransferQueueSizeFrames = 100;
 
 constexpr size_t kMaxNumBands = 3;
-constexpr size_t kSubFrameLength = 80;
+constexpr size_t kFrameSize = 160;
+constexpr size_t kSubFrameLength = kFrameSize / 2;
 
 constexpr size_t kBlockSize = kFftLengthBy2;
 constexpr size_t kBlockSizeLog2 = kFftLengthBy2Log2;
diff --git a/modules/audio_processing/aec3/block_processor.cc b/modules/audio_processing/aec3/block_processor.cc
index 8942570..bda2589 100644
--- a/modules/audio_processing/aec3/block_processor.cc
+++ b/modules/audio_processing/aec3/block_processor.cc
@@ -52,6 +52,7 @@
   void ProcessCapture(
       bool echo_path_gain_change,
       bool capture_signal_saturation,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture_block) override;
 
   void BufferRender(
@@ -105,6 +106,7 @@
 void BlockProcessorImpl::ProcessCapture(
     bool echo_path_gain_change,
     bool capture_signal_saturation,
+    std::vector<std::vector<std::vector<float>>>* linear_output,
     std::vector<std::vector<std::vector<float>>>* capture_block) {
   RTC_DCHECK(capture_block);
   RTC_DCHECK_EQ(NumBandsForRate(sample_rate_hz_), capture_block->size());
@@ -191,7 +193,7 @@
   if (has_delay_estimator || render_buffer_->HasReceivedBufferDelay()) {
     echo_remover_->ProcessCapture(
         echo_path_variability, capture_signal_saturation, estimated_delay_,
-        render_buffer_->GetRenderBuffer(), capture_block);
+        render_buffer_->GetRenderBuffer(), linear_output, capture_block);
   }
 
   // Update the metrics.
diff --git a/modules/audio_processing/aec3/block_processor.h b/modules/audio_processing/aec3/block_processor.h
index 755444a..9bb0cf1 100644
--- a/modules/audio_processing/aec3/block_processor.h
+++ b/modules/audio_processing/aec3/block_processor.h
@@ -59,6 +59,7 @@
   virtual void ProcessCapture(
       bool echo_path_gain_change,
       bool capture_signal_saturation,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture_block) = 0;
 
   // Buffers a block of render data supplied by a FrameBlocker object.
diff --git a/modules/audio_processing/aec3/block_processor_unittest.cc b/modules/audio_processing/aec3/block_processor_unittest.cc
index 9c315e1..2b928e8 100644
--- a/modules/audio_processing/aec3/block_processor_unittest.cc
+++ b/modules/audio_processing/aec3/block_processor_unittest.cc
@@ -48,7 +48,7 @@
                                       std::vector<float>(kBlockSize, 1000.f)));
   for (int k = 0; k < num_iterations; ++k) {
     block_processor->BufferRender(block);
-    block_processor->ProcessCapture(false, false, &block);
+    block_processor->ProcessCapture(false, false, nullptr, &block);
     block_processor->UpdateEchoLeakageStatus(false);
   }
 }
@@ -81,7 +81,8 @@
       std::vector<std::vector<float>>(kNumRenderChannels,
                                       std::vector<float>(kBlockSize - 1, 0.f)));
 
-  EXPECT_DEATH(block_processor->ProcessCapture(false, false, &block), "");
+  EXPECT_DEATH(block_processor->ProcessCapture(false, false, nullptr, &block),
+               "");
 }
 
 void RunRenderNumBandsVerificationTest(int sample_rate_hz) {
@@ -117,7 +118,8 @@
       std::vector<std::vector<float>>(kNumRenderChannels,
                                       std::vector<float>(kBlockSize, 0.f)));
 
-  EXPECT_DEATH(block_processor->ProcessCapture(false, false, &block), "");
+  EXPECT_DEATH(block_processor->ProcessCapture(false, false, nullptr, &block),
+               "");
 }
 #endif
 
@@ -172,7 +174,7 @@
       RandomizeSampleVector(&random_generator, render_block[0][0]);
       signal_delay_buffer.Delay(render_block[0][0], capture_block[0][0]);
       block_processor->BufferRender(render_block);
-      block_processor->ProcessCapture(false, false, &capture_block);
+      block_processor->ProcessCapture(false, false, nullptr, &capture_block);
     }
   }
 }
@@ -207,7 +209,7 @@
         .WillRepeatedly(Return(0));
     EXPECT_CALL(*render_delay_controller_mock, GetDelay(_, _, _))
         .Times(kNumBlocks);
-    EXPECT_CALL(*echo_remover_mock, ProcessCapture(_, _, _, _, _))
+    EXPECT_CALL(*echo_remover_mock, ProcessCapture(_, _, _, _, _, _))
         .Times(kNumBlocks);
     EXPECT_CALL(*echo_remover_mock, UpdateEchoLeakageStatus(_))
         .Times(kNumBlocks);
@@ -230,7 +232,7 @@
       RandomizeSampleVector(&random_generator, render_block[0][0]);
       signal_delay_buffer.Delay(render_block[0][0], capture_block[0][0]);
       block_processor->BufferRender(render_block);
-      block_processor->ProcessCapture(false, false, &capture_block);
+      block_processor->ProcessCapture(false, false, nullptr, &capture_block);
       block_processor->UpdateEchoLeakageStatus(false);
     }
   }
@@ -284,7 +286,7 @@
 TEST(BlockProcessor, NullProcessCaptureParameter) {
   EXPECT_DEATH(std::unique_ptr<BlockProcessor>(
                    BlockProcessor::Create(EchoCanceller3Config(), 16000, 1, 1))
-                   ->ProcessCapture(false, false, nullptr),
+                   ->ProcessCapture(false, false, nullptr, nullptr),
                "");
 }
 
diff --git a/modules/audio_processing/aec3/echo_canceller3.cc b/modules/audio_processing/aec3/echo_canceller3.cc
index 2b50e61..a68ae01 100644
--- a/modules/audio_processing/aec3/echo_canceller3.cc
+++ b/modules/audio_processing/aec3/echo_canceller3.cc
@@ -16,6 +16,7 @@
 #include "modules/audio_processing/high_pass_filter.h"
 #include "modules/audio_processing/logging/apm_data_dumper.h"
 #include "rtc_base/atomic_ops.h"
+#include "rtc_base/logging.h"
 #include "system_wrappers/include/field_trial.h"
 
 namespace webrtc {
@@ -87,28 +88,52 @@
 }
 
 void ProcessCaptureFrameContent(
+    AudioBuffer* linear_output,
     AudioBuffer* capture,
     bool level_change,
     bool saturated_microphone_signal,
     size_t sub_frame_index,
     FrameBlocker* capture_blocker,
+    BlockFramer* linear_output_framer,
     BlockFramer* output_framer,
     BlockProcessor* block_processor,
-    std::vector<std::vector<std::vector<float>>>* block,
-    std::vector<std::vector<rtc::ArrayView<float>>>* sub_frame_view) {
-  FillSubFrameView(capture, sub_frame_index, sub_frame_view);
-  capture_blocker->InsertSubFrameAndExtractBlock(*sub_frame_view, block);
+    std::vector<std::vector<std::vector<float>>>* linear_output_block,
+    std::vector<std::vector<rtc::ArrayView<float>>>*
+        linear_output_sub_frame_view,
+    std::vector<std::vector<std::vector<float>>>* capture_block,
+    std::vector<std::vector<rtc::ArrayView<float>>>* capture_sub_frame_view) {
+  FillSubFrameView(capture, sub_frame_index, capture_sub_frame_view);
+
+  if (linear_output) {
+    RTC_DCHECK(linear_output_framer);
+    RTC_DCHECK(linear_output_block);
+    RTC_DCHECK(linear_output_sub_frame_view);
+    FillSubFrameView(linear_output, sub_frame_index,
+                     linear_output_sub_frame_view);
+  }
+
+  capture_blocker->InsertSubFrameAndExtractBlock(*capture_sub_frame_view,
+                                                 capture_block);
   block_processor->ProcessCapture(level_change, saturated_microphone_signal,
-                                  block);
-  output_framer->InsertBlockAndExtractSubFrame(*block, sub_frame_view);
+                                  linear_output_block, capture_block);
+  output_framer->InsertBlockAndExtractSubFrame(*capture_block,
+                                               capture_sub_frame_view);
+
+  if (linear_output) {
+    RTC_DCHECK(linear_output_framer);
+    linear_output_framer->InsertBlockAndExtractSubFrame(
+        *linear_output_block, linear_output_sub_frame_view);
+  }
 }
 
 void ProcessRemainingCaptureFrameContent(
     bool level_change,
     bool saturated_microphone_signal,
     FrameBlocker* capture_blocker,
+    BlockFramer* linear_output_framer,
     BlockFramer* output_framer,
     BlockProcessor* block_processor,
+    std::vector<std::vector<std::vector<float>>>* linear_output_block,
     std::vector<std::vector<std::vector<float>>>* block) {
   if (!capture_blocker->IsBlockAvailable()) {
     return;
@@ -116,8 +141,13 @@
 
   capture_blocker->ExtractBlock(block);
   block_processor->ProcessCapture(level_change, saturated_microphone_signal,
-                                  block);
+                                  linear_output_block, block);
   output_framer->InsertBlock(*block);
+
+  if (linear_output_framer) {
+    RTC_DCHECK(linear_output_block);
+    linear_output_framer->InsertBlock(*linear_output_block);
+  }
 }
 
 void BufferRenderFrameContent(
@@ -295,12 +325,24 @@
 
   RTC_DCHECK_EQ(num_bands_, std::max(sample_rate_hz_, 16000) / 16000);
   RTC_DCHECK_GE(kMaxNumBands, num_bands_);
+
+  if (config_.filter.export_linear_aec_output) {
+    linear_output_framer_.reset(new BlockFramer(1, num_capture_channels_));
+    linear_output_block_ =
+        std::make_unique<std::vector<std::vector<std::vector<float>>>>(
+            1, std::vector<std::vector<float>>(
+                   num_capture_channels_, std::vector<float>(kBlockSize, 0.f)));
+    linear_output_sub_frame_view_ =
+        std::vector<std::vector<rtc::ArrayView<float>>>(
+            1, std::vector<rtc::ArrayView<float>>(num_capture_channels_));
+  }
 }
 
 EchoCanceller3::~EchoCanceller3() = default;
 
 void EchoCanceller3::AnalyzeRender(const AudioBuffer& render) {
   RTC_DCHECK_RUNS_SERIALIZED(&render_race_checker_);
+
   RTC_DCHECK_EQ(render.num_channels(), num_render_channels_);
   data_dumper_->DumpRaw("aec3_call_order",
                         static_cast<int>(EchoCanceller3ApiCall::kRender));
@@ -312,7 +354,6 @@
   RTC_DCHECK_RUNS_SERIALIZED(&capture_race_checker_);
   data_dumper_->DumpWav("aec3_capture_analyze_input", capture.num_frames(),
                         capture.channels_const()[0], sample_rate_hz_, 1);
-
   saturated_microphone_signal_ = false;
   for (size_t channel = 0; channel < capture.num_channels(); ++channel) {
     saturated_microphone_signal_ |=
@@ -325,6 +366,12 @@
 }
 
 void EchoCanceller3::ProcessCapture(AudioBuffer* capture, bool level_change) {
+  ProcessCapture(capture, nullptr, level_change);
+}
+
+void EchoCanceller3::ProcessCapture(AudioBuffer* capture,
+                                    AudioBuffer* linear_output,
+                                    bool level_change) {
   RTC_DCHECK_RUNS_SERIALIZED(&capture_race_checker_);
   RTC_DCHECK(capture);
   RTC_DCHECK_EQ(num_bands_, capture->num_bands());
@@ -333,6 +380,12 @@
   data_dumper_->DumpRaw("aec3_call_order",
                         static_cast<int>(EchoCanceller3ApiCall::kCapture));
 
+  if (linear_output && !linear_output_framer_) {
+    RTC_LOG(LS_ERROR) << "Trying to retrieve the linear AEC output without "
+                         "properly configuring AEC3.";
+    RTC_NOTREACHED();
+  }
+
   // Report capture call in the metrics and periodically update API call
   // metrics.
   api_call_metrics_.ReportCaptureCall();
@@ -349,19 +402,24 @@
 
   EmptyRenderQueue();
 
-  ProcessCaptureFrameContent(capture, level_change,
+  ProcessCaptureFrameContent(linear_output, capture, level_change,
                              saturated_microphone_signal_, 0, &capture_blocker_,
-                             &output_framer_, block_processor_.get(),
-                             &capture_block_, &capture_sub_frame_view_);
+                             linear_output_framer_.get(), &output_framer_,
+                             block_processor_.get(), linear_output_block_.get(),
+                             &linear_output_sub_frame_view_, &capture_block_,
+                             &capture_sub_frame_view_);
 
-  ProcessCaptureFrameContent(capture, level_change,
+  ProcessCaptureFrameContent(linear_output, capture, level_change,
                              saturated_microphone_signal_, 1, &capture_blocker_,
-                             &output_framer_, block_processor_.get(),
-                             &capture_block_, &capture_sub_frame_view_);
+                             linear_output_framer_.get(), &output_framer_,
+                             block_processor_.get(), linear_output_block_.get(),
+                             &linear_output_sub_frame_view_, &capture_block_,
+                             &capture_sub_frame_view_);
 
   ProcessRemainingCaptureFrameContent(
       level_change, saturated_microphone_signal_, &capture_blocker_,
-      &output_framer_, block_processor_.get(), &capture_block_);
+      linear_output_framer_.get(), &output_framer_, block_processor_.get(),
+      linear_output_block_.get(), &capture_block_);
 
   data_dumper_->DumpWav("aec3_capture_output", AudioBuffer::kSplitBandSize,
                         &capture->split_bands(0)[0][0], 16000, 1);
diff --git a/modules/audio_processing/aec3/echo_canceller3.h b/modules/audio_processing/aec3/echo_canceller3.h
index ce36cc1..a828d57 100644
--- a/modules/audio_processing/aec3/echo_canceller3.h
+++ b/modules/audio_processing/aec3/echo_canceller3.h
@@ -70,8 +70,6 @@
 // Main class for the echo canceller3.
 // It does 4 things:
 // -Receives 10 ms frames of band-split audio.
-// -Optionally applies an anti-hum (high-pass) filter on the
-// received signals.
 // -Provides the lower level echo canceller functionality with
 // blocks of 64 samples of audio data.
 // -Partially handles the jitter in the render and capture API
@@ -106,6 +104,10 @@
   // Processes the split-band domain capture signal in order to remove any echo
   // present in the signal.
   void ProcessCapture(AudioBuffer* capture, bool level_change) override;
+  // As above, but also returns the linear filter output.
+  void ProcessCapture(AudioBuffer* capture,
+                      AudioBuffer* linear_output,
+                      bool level_change) override;
   // Collect current metrics from the echo canceller.
   Metrics GetMetrics() const override;
   // Provides an optional external estimate of the audio buffer delay.
@@ -149,6 +151,8 @@
   const int num_bands_;
   const size_t num_render_channels_;
   const size_t num_capture_channels_;
+  std::unique_ptr<BlockFramer> linear_output_framer_
+      RTC_GUARDED_BY(capture_race_checker_);
   BlockFramer output_framer_ RTC_GUARDED_BY(capture_race_checker_);
   FrameBlocker capture_blocker_ RTC_GUARDED_BY(capture_race_checker_);
   FrameBlocker render_blocker_ RTC_GUARDED_BY(capture_race_checker_);
@@ -163,10 +167,14 @@
       false;
   std::vector<std::vector<std::vector<float>>> render_block_
       RTC_GUARDED_BY(capture_race_checker_);
+  std::unique_ptr<std::vector<std::vector<std::vector<float>>>>
+      linear_output_block_ RTC_GUARDED_BY(capture_race_checker_);
   std::vector<std::vector<std::vector<float>>> capture_block_
       RTC_GUARDED_BY(capture_race_checker_);
   std::vector<std::vector<rtc::ArrayView<float>>> render_sub_frame_view_
       RTC_GUARDED_BY(capture_race_checker_);
+  std::vector<std::vector<rtc::ArrayView<float>>> linear_output_sub_frame_view_
+      RTC_GUARDED_BY(capture_race_checker_);
   std::vector<std::vector<rtc::ArrayView<float>>> capture_sub_frame_view_
       RTC_GUARDED_BY(capture_race_checker_);
   BlockDelayBuffer block_delay_buffer_ RTC_GUARDED_BY(capture_race_checker_);
diff --git a/modules/audio_processing/aec3/echo_canceller3_unittest.cc b/modules/audio_processing/aec3/echo_canceller3_unittest.cc
index e7b9ddb..8d9199c 100644
--- a/modules/audio_processing/aec3/echo_canceller3_unittest.cc
+++ b/modules/audio_processing/aec3/echo_canceller3_unittest.cc
@@ -112,6 +112,7 @@
   void ProcessCapture(
       bool level_change,
       bool saturated_microphone_signal,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture_block) override {}
 
   void BufferRender(
@@ -137,6 +138,7 @@
   void ProcessCapture(
       bool level_change,
       bool saturated_microphone_signal,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture_block) override {
     std::vector<std::vector<std::vector<float>>> render_block =
         received_render_blocks_.front();
@@ -267,17 +269,17 @@
 
     switch (echo_path_change_test_variant) {
       case EchoPathChangeTestVariant::kNone:
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _, _))
             .Times(kExpectedNumBlocksToProcess);
         break;
       case EchoPathChangeTestVariant::kOneSticky:
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _, _))
             .Times(kExpectedNumBlocksToProcess);
         break;
       case EchoPathChangeTestVariant::kOneNonSticky:
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(true, _, _, _))
             .Times(kNumFullBlocksPerFrame);
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(false, _, _, _))
             .Times(kExpectedNumBlocksToProcess - kNumFullBlocksPerFrame);
         break;
     }
@@ -338,7 +340,7 @@
             new StrictMock<webrtc::test::MockBlockProcessor>());
     EXPECT_CALL(*block_processor_mock, BufferRender(_))
         .Times(kExpectedNumBlocksToProcess);
-    EXPECT_CALL(*block_processor_mock, ProcessCapture(_, _, _))
+    EXPECT_CALL(*block_processor_mock, ProcessCapture(_, _, _, _))
         .Times(kExpectedNumBlocksToProcess);
 
     switch (leakage_report_variant) {
@@ -429,21 +431,21 @@
 
     switch (saturation_variant) {
       case SaturationTestVariant::kNone:
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _, _))
             .Times(kExpectedNumBlocksToProcess);
         break;
       case SaturationTestVariant::kOneNegative: {
         ::testing::InSequence s;
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _, _))
             .Times(kNumFullBlocksPerFrame);
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _, _))
             .Times(kExpectedNumBlocksToProcess - kNumFullBlocksPerFrame);
       } break;
       case SaturationTestVariant::kOnePositive: {
         ::testing::InSequence s;
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, true, _, _))
             .Times(kNumFullBlocksPerFrame);
-        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _))
+        EXPECT_CALL(*block_processor_mock, ProcessCapture(_, false, _, _))
             .Times(kExpectedNumBlocksToProcess - kNumFullBlocksPerFrame);
       } break;
     }
diff --git a/modules/audio_processing/aec3/echo_remover.cc b/modules/audio_processing/aec3/echo_remover.cc
index bf68f36..89ba736 100644
--- a/modules/audio_processing/aec3/echo_remover.cc
+++ b/modules/audio_processing/aec3/echo_remover.cc
@@ -123,6 +123,7 @@
       bool capture_signal_saturation,
       const absl::optional<DelayEstimate>& external_delay,
       RenderBuffer* render_buffer,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture) override;
 
   // Updates the status on whether echo leakage is detected in the output of the
@@ -235,6 +236,7 @@
     bool capture_signal_saturation,
     const absl::optional<DelayEstimate>& external_delay,
     RenderBuffer* render_buffer,
+    std::vector<std::vector<std::vector<float>>>* linear_output,
     std::vector<std::vector<std::vector<float>>>* capture) {
   ++block_counter_;
   const std::vector<std::vector<std::vector<float>>>& x =
@@ -367,6 +369,16 @@
     E[ch].Spectrum(optimization_, E2[ch]);
   }
 
+  // Optionally return the linear filter output.
+  if (linear_output) {
+    RTC_DCHECK_GE(1, linear_output->size());
+    RTC_DCHECK_EQ(num_capture_channels_, linear_output[0].size());
+    for (size_t ch = 0; ch < num_capture_channels_; ++ch) {
+      RTC_DCHECK_EQ(kBlockSize, (*linear_output)[0][ch].size());
+      std::copy(e[ch].begin(), e[ch].end(), (*linear_output)[0][ch].begin());
+    }
+  }
+
   // Update the AEC state information.
   aec_state_.Update(external_delay, subtractor_.FilterFrequencyResponses(),
                     subtractor_.FilterImpulseResponses(), *render_buffer, E2,
diff --git a/modules/audio_processing/aec3/echo_remover.h b/modules/audio_processing/aec3/echo_remover.h
index 6098a68..ef41646 100644
--- a/modules/audio_processing/aec3/echo_remover.h
+++ b/modules/audio_processing/aec3/echo_remover.h
@@ -42,6 +42,7 @@
       bool capture_signal_saturation,
       const absl::optional<DelayEstimate>& external_delay,
       RenderBuffer* render_buffer,
+      std::vector<std::vector<std::vector<float>>>* linear_output,
       std::vector<std::vector<std::vector<float>>>* capture) = 0;
 
   // Updates the status on whether echo leakage is detected in the output of the
diff --git a/modules/audio_processing/aec3/echo_remover_unittest.cc b/modules/audio_processing/aec3/echo_remover_unittest.cc
index 15d0913..d79993a 100644
--- a/modules/audio_processing/aec3/echo_remover_unittest.cc
+++ b/modules/audio_processing/aec3/echo_remover_unittest.cc
@@ -73,9 +73,9 @@
           render_buffer->Insert(render);
           render_buffer->PrepareCaptureProcessing();
 
-          remover->ProcessCapture(echo_path_variability,
-                                  k % 2 == 0 ? true : false, delay_estimate,
-                                  render_buffer->GetRenderBuffer(), &capture);
+          remover->ProcessCapture(
+              echo_path_variability, k % 2 == 0 ? true : false, delay_estimate,
+              render_buffer->GetRenderBuffer(), nullptr, &capture);
         }
       }
     }
@@ -107,10 +107,10 @@
                                    1, std::vector<float>(kBlockSize - 1, 0.f)));
     EchoPathVariability echo_path_variability(
         false, EchoPathVariability::DelayAdjustment::kNone, false);
-    EXPECT_DEATH(
-        remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                render_buffer->GetRenderBuffer(), &capture),
-        "");
+    EXPECT_DEATH(remover->ProcessCapture(
+                     echo_path_variability, false, delay_estimate,
+                     render_buffer->GetRenderBuffer(), nullptr, &capture),
+                 "");
   }
 }
 
@@ -131,10 +131,10 @@
                                         std::vector<float>(kBlockSize, 0.f)));
     EchoPathVariability echo_path_variability(
         false, EchoPathVariability::DelayAdjustment::kNone, false);
-    EXPECT_DEATH(
-        remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                render_buffer->GetRenderBuffer(), &capture),
-        "");
+    EXPECT_DEATH(remover->ProcessCapture(
+                     echo_path_variability, false, delay_estimate,
+                     render_buffer->GetRenderBuffer(), nullptr, &capture),
+                 "");
   }
 }
 
@@ -147,10 +147,10 @@
       RenderDelayBuffer::Create(EchoCanceller3Config(), 16000, 1));
   EchoPathVariability echo_path_variability(
       false, EchoPathVariability::DelayAdjustment::kNone, false);
-  EXPECT_DEATH(
-      remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                              render_buffer->GetRenderBuffer(), nullptr),
-      "");
+  EXPECT_DEATH(remover->ProcessCapture(
+                   echo_path_variability, false, delay_estimate,
+                   render_buffer->GetRenderBuffer(), nullptr, nullptr),
+               "");
 }
 
 #endif
@@ -222,7 +222,8 @@
           render_buffer->PrepareCaptureProcessing();
 
           remover->ProcessCapture(echo_path_variability, false, delay_estimate,
-                                  render_buffer->GetRenderBuffer(), &y);
+                                  render_buffer->GetRenderBuffer(), nullptr,
+                                  &y);
 
           if (k > kNumBlocksToProcess / 2) {
             output_energy = std::inner_product(y[0][0].begin(), y[0][0].end(),
diff --git a/modules/audio_processing/aec3/mock/mock_block_processor.h b/modules/audio_processing/aec3/mock/mock_block_processor.h
index 634d26e..e9a95c8 100644
--- a/modules/audio_processing/aec3/mock/mock_block_processor.h
+++ b/modules/audio_processing/aec3/mock/mock_block_processor.h
@@ -24,10 +24,11 @@
   MockBlockProcessor();
   virtual ~MockBlockProcessor();
 
-  MOCK_METHOD3(
+  MOCK_METHOD4(
       ProcessCapture,
       void(bool level_change,
            bool saturated_microphone_signal,
+           std::vector<std::vector<std::vector<float>>>* linear_output,
            std::vector<std::vector<std::vector<float>>>* capture_block));
   MOCK_METHOD1(BufferRender,
                void(const std::vector<std::vector<std::vector<float>>>& block));
diff --git a/modules/audio_processing/aec3/mock/mock_echo_remover.h b/modules/audio_processing/aec3/mock/mock_echo_remover.h
index f8dd348..6c580f3 100644
--- a/modules/audio_processing/aec3/mock/mock_echo_remover.h
+++ b/modules/audio_processing/aec3/mock/mock_echo_remover.h
@@ -27,11 +27,12 @@
   MockEchoRemover();
   virtual ~MockEchoRemover();
 
-  MOCK_METHOD5(ProcessCapture,
+  MOCK_METHOD6(ProcessCapture,
                void(EchoPathVariability echo_path_variability,
                     bool capture_signal_saturation,
                     const absl::optional<DelayEstimate>& delay_estimate,
                     RenderBuffer* render_buffer,
+                    std::vector<std::vector<std::vector<float>>>* linear_output,
                     std::vector<std::vector<std::vector<float>>>* capture));
   MOCK_CONST_METHOD0(Delay, absl::optional<int>());
   MOCK_METHOD1(UpdateEchoLeakageStatus, void(bool leakage_detected));
diff --git a/modules/audio_processing/aec3/suppression_gain.cc b/modules/audio_processing/aec3/suppression_gain.cc
index d1ef326..bd7a3d6 100644
--- a/modules/audio_processing/aec3/suppression_gain.cc
+++ b/modules/audio_processing/aec3/suppression_gain.cc
@@ -343,13 +343,6 @@
     std::array<float, kFftLengthBy2Plus1>* low_band_gain) {
   RTC_DCHECK(high_bands_gain);
   RTC_DCHECK(low_band_gain);
-  const auto& cfg = config_.suppressor;
-
-  if (cfg.enforce_transparent) {
-    low_band_gain->fill(1.f);
-    *high_bands_gain = cfg.enforce_empty_higher_bands ? 0.f : 1.f;
-    return;
-  }
 
   // Update the nearend state selection.
   dominant_nearend_detector_.Update(nearend_spectrum, residual_echo_spectrum,
@@ -360,11 +353,6 @@
   LowerBandGain(low_noise_render, aec_state, nearend_spectrum,
                 residual_echo_spectrum, comfort_noise_spectrum, low_band_gain);
 
-  if (cfg.enforce_empty_higher_bands) {
-    *high_bands_gain = 0.f;
-    return;
-  }
-
   // Compute the gain for the upper bands.
   const absl::optional<int> narrow_peak_band =
       render_signal_analyzer.NarrowPeakBand();