From fc737e5442792d72de22d1271471b9d7a0e45c0b Mon Sep 17 00:00:00 2001
From: aluebs <aluebs@webrtc.org>
Date: Wed, 30 Mar 2016 09:37:43 -0700
Subject: [PATCH] Fix division by zero in NonlinearBeamformer

BUG=webrtc:5703

Review URL: https://codereview.webrtc.org/1841323002

Cr-Commit-Position: refs/heads/master@{#12163}
---
 .../beamformer/nonlinear_beamformer.cc        | 13 +++++++++--
 .../nonlinear_beamformer_unittest.cc          | 23 ++++++++-----------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
index 6ea7234f6f..118b38d487 100644
--- a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
+++ b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc
@@ -471,8 +471,17 @@ float NonlinearBeamformer::CalculatePostfilterMask(
     ratio = rpsiw / rpsim;
   }
 
-  return (1.f - std::min(kCutOffConstant, ratio / rmw_r)) /
-         (1.f - std::min(kCutOffConstant, ratio / ratio_rxiw_rxim));
+  float numerator = 1.f - kCutOffConstant;
+  if (rmw_r > 0.f) {
+    numerator = 1.f - std::min(kCutOffConstant, ratio / rmw_r);
+  }
+
+  float denominator = 1.f - kCutOffConstant;
+  if (ratio_rxiw_rxim > 0.f) {
+    denominator = 1.f - std::min(kCutOffConstant, ratio / ratio_rxiw_rxim);
+  }
+
+  return numerator / denominator;
 }
 
 void NonlinearBeamformer::ApplyMasks(const complex_f* const* input,
diff --git a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer_unittest.cc b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer_unittest.cc
index 66a564c32c..fbf0ec098f 100644
--- a/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer_unittest.cc
+++ b/webrtc/modules/audio_processing/beamformer/nonlinear_beamformer_unittest.cc
@@ -249,9 +249,6 @@ TEST(NonlinearBeamformerTest, InterfAnglesTakeAmbiguityIntoAccount) {
   }
 }
 
-// TODO(peah): Reenable all bitexactness tests once the division-by-zero issue
-// has been resolved.
-
 // TODO(peah): Investigate why the nonlinear_beamformer.cc causes a DCHECK in
 // this setup.
 TEST(BeamformerBitExactnessTest,
@@ -264,7 +261,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo16kHz_ArrayGeometry1_TargetDirection1) {
+     Stereo16kHz_ArrayGeometry1_TargetDirection1) {
   const float kOutputReference[] = {0.000064f, 0.000211f, 0.000075f,
                                     0.000064f, 0.000211f, 0.000075f};
 
@@ -273,7 +270,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo32kHz_ArrayGeometry1_TargetDirection1) {
+     Stereo32kHz_ArrayGeometry1_TargetDirection1) {
   const float kOutputReference[] = {0.000183f, 0.000183f, 0.000183f,
                                     0.000183f, 0.000183f, 0.000183f};
 
@@ -282,7 +279,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo48kHz_ArrayGeometry1_TargetDirection1) {
+     Stereo48kHz_ArrayGeometry1_TargetDirection1) {
   const float kOutputReference[] = {0.000155f, 0.000152f, 0.000159f,
                                     0.000155f, 0.000152f, 0.000159f};
 
@@ -302,7 +299,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo16kHz_ArrayGeometry1_TargetDirection2) {
+     Stereo16kHz_ArrayGeometry1_TargetDirection2) {
   const float kOutputReference[] = {0.001144f, -0.001026f, 0.001074f,
                                     0.001144f, -0.001026f, 0.001074f};
 
@@ -311,7 +308,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo32kHz_ArrayGeometry1_TargetDirection2) {
+     Stereo32kHz_ArrayGeometry1_TargetDirection2) {
   const float kOutputReference[] = {0.000732f, -0.000397f, 0.000610f,
                                     0.000732f, -0.000397f, 0.000610f};
 
@@ -320,7 +317,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo48kHz_ArrayGeometry1_TargetDirection2) {
+     Stereo48kHz_ArrayGeometry1_TargetDirection2) {
   const float kOutputReference[] = {0.000106f, -0.000464f, 0.000188f,
                                     0.000106f, -0.000464f, 0.000188f};
 
@@ -329,7 +326,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo8kHz_ArrayGeometry2_TargetDirection2) {
+     Stereo8kHz_ArrayGeometry2_TargetDirection2) {
   const float kOutputReference[] = {-0.000649f, 0.000576f, -0.000148f,
                                     -0.000649f, 0.000576f, -0.000148f};
 
@@ -338,7 +335,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo16kHz_ArrayGeometry2_TargetDirection2) {
+     Stereo16kHz_ArrayGeometry2_TargetDirection2) {
   const float kOutputReference[] = {0.000808f, -0.000695f, 0.000739f,
                                     0.000808f, -0.000695f, 0.000739f};
 
@@ -347,7 +344,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo32kHz_ArrayGeometry2_TargetDirection2) {
+     Stereo32kHz_ArrayGeometry2_TargetDirection2) {
   const float kOutputReference[] = {0.000580f, -0.000183f, 0.000458f,
                                     0.000580f, -0.000183f, 0.000458f};
 
@@ -356,7 +353,7 @@ TEST(BeamformerBitExactnessTest,
 }
 
 TEST(BeamformerBitExactnessTest,
-     DISABLED_Stereo48kHz_ArrayGeometry2_TargetDirection2) {
+     Stereo48kHz_ArrayGeometry2_TargetDirection2) {
   const float kOutputReference[] = {0.000075f, -0.000288f, 0.000156f,
                                     0.000075f, -0.000288f, 0.000156f};