From 765edc34257a439bb3d9acc7d4c6aaf205b4e11f Mon Sep 17 00:00:00 2001
From: ivoc <ivoc@webrtc.org>
Date: Thu, 17 Nov 2016 07:10:16 -0800
Subject: [PATCH] Update the alpha value in the echo detector.

BUG=webrtc:6525

Review-Url: https://codereview.webrtc.org/2506643002
Cr-Commit-Position: refs/heads/master@{#15136}
---
 .../echo_detector/mean_variance_estimator.cc                | 2 +-
 .../echo_detector/mean_variance_estimator_unittest.cc       | 6 +++---
 .../echo_detector/normalized_covariance_estimator.cc        | 2 +-
 .../audio_processing/residual_echo_detector_unittest.cc     | 4 ++--
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc b/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc
index e1236159e1..06baf68b8a 100644
--- a/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc
+++ b/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc
@@ -18,7 +18,7 @@ namespace webrtc {
 namespace {
 
 // Parameter controlling the adaptation speed.
-constexpr float kAlpha = 0.01f;
+constexpr float kAlpha = 0.001f;
 
 }  // namespace
 
diff --git a/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator_unittest.cc b/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator_unittest.cc
index ec4350f45e..ba45745606 100644
--- a/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator_unittest.cc
+++ b/webrtc/modules/audio_processing/echo_detector/mean_variance_estimator_unittest.cc
@@ -31,7 +31,7 @@ TEST(MeanVarianceEstimatorTests, InsertTwoValues) {
 TEST(MeanVarianceEstimatorTests, InsertZeroes) {
   MeanVarianceEstimator test_estimator;
   // Insert the same value many times.
-  for (size_t i = 0; i < 10000; i++) {
+  for (size_t i = 0; i < 20000; i++) {
     test_estimator.Update(0.f);
   }
   EXPECT_EQ(test_estimator.mean(), 0.f);
@@ -40,7 +40,7 @@ TEST(MeanVarianceEstimatorTests, InsertZeroes) {
 
 TEST(MeanVarianceEstimatorTests, ConstantValueTest) {
   MeanVarianceEstimator test_estimator;
-  for (size_t i = 0; i < 10000; i++) {
+  for (size_t i = 0; i < 20000; i++) {
     test_estimator.Update(3.f);
   }
   // The mean should be close to three, and the standard deviation should be
@@ -51,7 +51,7 @@ TEST(MeanVarianceEstimatorTests, ConstantValueTest) {
 
 TEST(MeanVarianceEstimatorTests, AlternatingValueTest) {
   MeanVarianceEstimator test_estimator;
-  for (size_t i = 0; i < 10000; i++) {
+  for (size_t i = 0; i < 20000; i++) {
     test_estimator.Update(1.f);
     test_estimator.Update(-1.f);
   }
diff --git a/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc b/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc
index aad806d0e4..0b8b68bfbd 100644
--- a/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc
+++ b/webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc
@@ -14,7 +14,7 @@ namespace webrtc {
 namespace {
 
 // Parameter controlling the adaptation speed.
-constexpr float kAlpha = 0.01f;
+constexpr float kAlpha = 0.001f;
 
 }  // namespace
 
diff --git a/webrtc/modules/audio_processing/residual_echo_detector_unittest.cc b/webrtc/modules/audio_processing/residual_echo_detector_unittest.cc
index cde731d769..0784a4f9f7 100644
--- a/webrtc/modules/audio_processing/residual_echo_detector_unittest.cc
+++ b/webrtc/modules/audio_processing/residual_echo_detector_unittest.cc
@@ -91,8 +91,8 @@ TEST(ResidualEchoDetectorTests, EchoWithRenderClockDrift) {
   // render buffer, clock drift can only be discovered after a certain delay.
   // A growing buffer can be caused by jitter or clock drift and it's not
   // possible to make this decision right away. For this reason we only expect
-  // an echo likelihood of 80% in this test.
-  EXPECT_GT(echo_detector.echo_likelihood(), 0.8f);
+  // an echo likelihood of 75% in this test.
+  EXPECT_GT(echo_detector.echo_likelihood(), 0.75f);
 }
 
 TEST(ResidualEchoDetectorTests, EchoWithCaptureClockDrift) {