From 7bd5f253bc09fe18bc4190fe88dbba9792ce32ae Mon Sep 17 00:00:00 2001
From: aluebs <aluebs@webrtc.org>
Date: Tue, 21 Jun 2016 11:30:25 -0700
Subject: [PATCH] Fine tune the IntelligibilityEnhancer

Label less chunks as speech, adapt slower and be more conservative with the maximum gain it can apply.

Review-Url: https://codereview.webrtc.org/2087623003
Cr-Commit-Position: refs/heads/master@{#13242}
---
 .../intelligibility/intelligibility_enhancer.cc           | 8 ++++----
 .../intelligibility/intelligibility_enhancer_unittest.cc  | 2 +-
 .../intelligibility/intelligibility_utils.cc              | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.cc
index a10d10a75e..243bd12229 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.cc
@@ -31,11 +31,11 @@ const float kClipFreqKhz = 0.2f;
 const float kKbdAlpha = 1.5f;
 const float kLambdaBot = -1.f;      // Extreme values in bisection
 const float kLambdaTop = -1e-5f;      // search for lamda.
-const float kVoiceProbabilityThreshold = 0.02f;
+const float kVoiceProbabilityThreshold = 0.5f;
 // Number of chunks after voice activity which is still considered speech.
-const size_t kSpeechOffsetDelay = 80;
-const float kDecayRate = 0.994f;              // Power estimation decay rate.
-const float kMaxRelativeGainChange = 0.006f;
+const size_t kSpeechOffsetDelay = 10;
+const float kDecayRate = 0.995f;              // Power estimation decay rate.
+const float kMaxRelativeGainChange = 0.005f;
 const float kRho = 0.0004f;  // Default production and interpretation SNR.
 const float kPowerNormalizationFactor = 1.f / (1 << 30);
 const float kMaxActiveSNR = 128.f;  // 21dB
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer_unittest.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer_unittest.cc
index 30035ab16e..852357e2da 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer_unittest.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer_unittest.cc
@@ -409,7 +409,7 @@ TEST_F(IntelligibilityEnhancerTest, TestSolveForGains) {
 TEST_F(IntelligibilityEnhancerTest, TestNoiseGainHasExpectedResult) {
   const int kGainDB = 6;
   const float kGainFactor = std::pow(10.f, kGainDB / 20.f);
-  const float kTolerance = 0.003f;
+  const float kTolerance = 0.007f;
   std::vector<float> noise(kNumNoiseBins);
   std::vector<float> noise_psd(kNumNoiseBins);
   std::generate(noise.begin(), noise.end(), float_rand);
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
index 3675f66caf..dfa912b31f 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
@@ -23,7 +23,7 @@ namespace intelligibility {
 namespace {
 
 const float kMinFactor = 0.01f;
-const float kMaxFactor = 1000.f;
+const float kMaxFactor = 100.f;
 
 // Return |current| changed towards |target|, with the relative change being at
 // most |limit|.