Transparency improvements in the echo canceller 3

webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc

Index: webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc
diff --git a/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc
index 474174c2ee915d00eefd28d1574a077146c6d4cf..32b20a4950444232a04d55f25cb00c10d92a2c18 100644
--- a/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc
+++ b/webrtc/modules/audio_processing/aec3/adaptive_fir_filter_unittest.cc
@@ -308,7 +308,8 @@ TEST(AdaptiveFirFilter, FilterAndAdapt) {
   AecState aec_state(0.f);
   RenderSignalAnalyzer render_signal_analyzer;
   std::vector<float> e(kBlockSize, 0.f);
-  std::array<float, kFftLength> s;
+  std::array<float, kFftLength> s_scratch;
+  std::array<float, kBlockSize> s;
   FftData S;
   FftData G;
   FftData E;
@@ -348,20 +349,24 @@ TEST(AdaptiveFirFilter, FilterAndAdapt) {
       render_signal_analyzer.Update(render_buffer, aec_state.FilterDelay());
 
       filter.Filter(render_buffer, &S);
-      fft.Ifft(S, &s);
-      std::transform(y.begin(), y.end(), s.begin() + kFftLengthBy2, e.begin(),
+      fft.Ifft(S, &s_scratch);
+      std::transform(y.begin(), y.end(), s_scratch.begin() + kFftLengthBy2,
+                     e.begin(),
                      [&](float a, float b) { return a - b * kScale; });
       std::for_each(e.begin(), e.end(),
                     [](float& a) { a = rtc::SafeClamp(a, -32768.f, 32767.f); });
       fft.ZeroPaddedFft(e, &E);
+      for (size_t k = 0; k < kBlockSize; ++k) {
+        s[k] = kScale * s_scratch[k + kFftLengthBy2];
+      }
 
       gain.Compute(render_buffer, render_signal_analyzer, E,
                    filter.SizePartitions(), false, &G);
       filter.Adapt(render_buffer, G);
       aec_state.HandleEchoPathChange(EchoPathVariability(false, false));
       aec_state.Update(filter.FilterFrequencyResponse(),
-                       rtc::Optional<size_t>(), render_buffer, E2_main, Y2,
-                       x[0], false);
+                       filter.FilterImpulseResponse(), rtc::Optional<size_t>(),
+                       render_buffer, E2_main, Y2, x[0], s, false);
     }
     // Verify that the filter is able to perform well.
     EXPECT_LT(1000 * std::inner_product(e.begin(), e.end(), e.begin(), 0.f),