Disable high-pass filtering of the AEC reference
Currently the echo canceller reference signal is high-pass filtered to
avoid the need of modeling the capture-side high-pass filter as part of
the echo path.
This can lead to the lowest frequency bins of the linear filter
diverging as there is little low-frequency content available for
training. Over time the filter can output an increasing amount of
low-frequency power, which in turn affects the filter's ability to
adapt properly.
Disabling the high-pass filtering of the echo canceller reference solves
this issue, resulting in improved filter convergence.
Bug: webrtc:12265
Change-Id: Ic526a4b1b73e1808cfcd96a8cdee801b96a27671
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208288
Reviewed-by: Per Åhgren <peah@webrtc.org>
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33322}
diff --git a/modules/audio_processing/aec3/echo_canceller3.cc b/modules/audio_processing/aec3/echo_canceller3.cc
index 98da232..0f8e35d 100644
--- a/modules/audio_processing/aec3/echo_canceller3.cc
+++ b/modules/audio_processing/aec3/echo_canceller3.cc
@@ -251,6 +251,10 @@
adjusted_cfg.filter.initial_state_seconds = 2.0f;
}
+ if (field_trial::IsEnabled("WebRTC-Aec3HighPassFilterEchoReference")) {
+ adjusted_cfg.filter.high_pass_filter_echo_reference = true;
+ }
+
if (field_trial::IsEnabled("WebRTC-Aec3EchoSaturationDetectionKillSwitch")) {
adjusted_cfg.ep_strength.echo_can_saturate = false;
}
@@ -574,6 +578,7 @@
class EchoCanceller3::RenderWriter {
public:
RenderWriter(ApmDataDumper* data_dumper,
+ const EchoCanceller3Config& config,
SwapQueue<std::vector<std::vector<std::vector<float>>>,
Aec3RenderQueueItemVerifier>* render_transfer_queue,
size_t num_bands,
@@ -590,7 +595,7 @@
ApmDataDumper* data_dumper_;
const size_t num_bands_;
const size_t num_channels_;
- HighPassFilter high_pass_filter_;
+ std::unique_ptr<HighPassFilter> high_pass_filter_;
std::vector<std::vector<std::vector<float>>> render_queue_input_frame_;
SwapQueue<std::vector<std::vector<std::vector<float>>>,
Aec3RenderQueueItemVerifier>* render_transfer_queue_;
@@ -598,6 +603,7 @@
EchoCanceller3::RenderWriter::RenderWriter(
ApmDataDumper* data_dumper,
+ const EchoCanceller3Config& config,
SwapQueue<std::vector<std::vector<std::vector<float>>>,
Aec3RenderQueueItemVerifier>* render_transfer_queue,
size_t num_bands,
@@ -605,7 +611,6 @@
: data_dumper_(data_dumper),
num_bands_(num_bands),
num_channels_(num_channels),
- high_pass_filter_(16000, num_channels),
render_queue_input_frame_(
num_bands_,
std::vector<std::vector<float>>(
@@ -613,6 +618,9 @@
std::vector<float>(AudioBuffer::kSplitBandSize, 0.f))),
render_transfer_queue_(render_transfer_queue) {
RTC_DCHECK(data_dumper);
+ if (config.filter.high_pass_filter_echo_reference) {
+ high_pass_filter_ = std::make_unique<HighPassFilter>(16000, num_channels);
+ }
}
EchoCanceller3::RenderWriter::~RenderWriter() = default;
@@ -631,7 +639,9 @@
CopyBufferIntoFrame(input, num_bands_, num_channels_,
&render_queue_input_frame_);
- high_pass_filter_.Process(&render_queue_input_frame_[0]);
+ if (high_pass_filter_) {
+ high_pass_filter_->Process(&render_queue_input_frame_[0]);
+ }
static_cast<void>(render_transfer_queue_->Insert(&render_queue_input_frame_));
}
@@ -704,7 +714,7 @@
config_.delay.fixed_capture_delay_samples));
}
- render_writer_.reset(new RenderWriter(data_dumper_.get(),
+ render_writer_.reset(new RenderWriter(data_dumper_.get(), config_,
&render_transfer_queue_, num_bands_,
num_render_channels_));
diff --git a/modules/audio_processing/aec3/echo_canceller3_unittest.cc b/modules/audio_processing/aec3/echo_canceller3_unittest.cc
index a02cfa3..acf8473 100644
--- a/modules/audio_processing/aec3/echo_canceller3_unittest.cc
+++ b/modules/audio_processing/aec3/echo_canceller3_unittest.cc
@@ -252,8 +252,6 @@
capture_output.push_back(capture_buffer_.split_bands(0)[0][k]);
}
}
- HighPassFilter hp_filter(16000, 1);
- hp_filter.Process(&render_input);
EXPECT_TRUE(
VerifyOutputFrameBitexactness(render_input[0], capture_output, -64));
@@ -545,8 +543,6 @@
capture_output.push_back(capture_buffer_.split_bands(0)[0][k]);
}
}
- HighPassFilter hp_filter(16000, 1);
- hp_filter.Process(&render_input);
EXPECT_TRUE(
VerifyOutputFrameBitexactness(render_input[0], capture_output, -64));
diff --git a/modules/audio_processing/audio_processing_unittest.cc b/modules/audio_processing/audio_processing_unittest.cc
index e3aedf6..4c879c7 100644
--- a/modules/audio_processing/audio_processing_unittest.cc
+++ b/modules/audio_processing/audio_processing_unittest.cc
@@ -2216,7 +2216,7 @@
std::make_tuple(32000, 44100, 16000, 44100, 19, 15),
std::make_tuple(32000, 32000, 48000, 32000, 40, 35),
std::make_tuple(32000, 32000, 32000, 32000, 0, 0),
- std::make_tuple(32000, 32000, 16000, 32000, 40, 20),
+ std::make_tuple(32000, 32000, 16000, 32000, 39, 20),
std::make_tuple(32000, 16000, 48000, 16000, 25, 20),
std::make_tuple(32000, 16000, 32000, 16000, 25, 20),
std::make_tuple(32000, 16000, 16000, 16000, 25, 0),
@@ -2231,7 +2231,7 @@
std::make_tuple(16000, 32000, 32000, 32000, 25, 0),
std::make_tuple(16000, 32000, 16000, 32000, 25, 20),
std::make_tuple(16000, 16000, 48000, 16000, 39, 20),
- std::make_tuple(16000, 16000, 32000, 16000, 40, 20),
+ std::make_tuple(16000, 16000, 32000, 16000, 39, 20),
std::make_tuple(16000, 16000, 16000, 16000, 0, 0)));
#elif defined(WEBRTC_AUDIOPROC_FIXED_PROFILE)