From 3ab2f14d56db91665002f36f899c0a97f926d91f Mon Sep 17 00:00:00 2001
From: ekmeyerson <ekmeyerson@webrtc.org>
Date: Thu, 23 Jul 2015 12:15:24 -0700
Subject: [PATCH] Remove C++11 calls from intelligibility_utils

The C++11 here was overkill. This replaces it with simpler logic that
covers all cases encountered so far in practice.

The problem was previously brought up here: https://codereview.webrtc.org/1250663007/

BUG=427718, 487341, webrtc:4866
R=andrew@webrtc.org

Review URL: https://codereview.webrtc.org/1242943008

Cr-Commit-Position: refs/heads/master@{#9627}
---
 .../intelligibility/intelligibility_utils.cc  | 31 +++----------------
 .../intelligibility/intelligibility_utils.h   |  6 ----
 .../intelligibility_utils_unittest.cc         | 10 +-----
 3 files changed, 6 insertions(+), 41 deletions(-)

diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
index 824b1676d8..00d9b53658 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
@@ -15,6 +15,7 @@
 #include "webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h"
 
 #include <math.h>
+#include <stdlib.h>
 #include <string.h>
 #include <algorithm>
 
@@ -31,28 +32,12 @@ float UpdateFactor(float target, float current, float limit) {
   return current + sign * fminf(delta, limit);
 }
 
-bool cplxfinite(complex<float> c) {
-  return std::isfinite(c.real()) && std::isfinite(c.imag());
-}
-
-bool cplxnormal(complex<float> c) {
-  return std::isnormal(c.real()) && std::isnormal(c.imag());
+float AddDitherIfZero(float value) {
+  return value == 0.f ? std::rand() * 0.01f / RAND_MAX : value;
 }
 
 complex<float> zerofudge(complex<float> c) {
-  const static complex<float> fudge[7] = {{0.001f, 0.002f},
-                                          {0.008f, 0.001f},
-                                          {0.003f, 0.008f},
-                                          {0.0006f, 0.0009f},
-                                          {0.001f, 0.004f},
-                                          {0.003f, 0.004f},
-                                          {0.002f, 0.009f}};
-  static int fudge_index = 0;
-  if (cplxfinite(c) && !cplxnormal(c)) {
-    fudge_index = (fudge_index + 1) % 7;
-    return c + fudge[fudge_index];
-  }
-  return c;
+  return complex<float>(AddDitherIfZero(c.real()), AddDitherIfZero(c.imag()));
 }
 
 complex<float> NewMean(complex<float> mean, complex<float> data, int count) {
@@ -136,10 +121,7 @@ void VarianceArray::InfiniteStep(const complex<float>* data, bool skip_fudge) {
           (old_sum + std::conj(sample - old_mean) * (sample - running_mean_[i]))
               .real();
       variance_[i] =
-          conj_sum_[i] / (count_ - 1);  // + fudge[fudge_index].real();
-      // if (skip_fudge) {
-      //   variance_[i] -= fudge[fudge_index].real();
-      // }
+          conj_sum_[i] / (count_ - 1);
     }
     array_mean_ += (variance_[i] - array_mean_) / (i + 1);
   }
@@ -164,9 +146,6 @@ void VarianceArray::DecayStep(const complex<float>* data, bool /*dummy*/) {
       running_mean_[i] = decay_ * prev + (1.0f - decay_) * sample;
       running_mean_sq_[i] =
           decay_ * prev2 + (1.0f - decay_) * sample * std::conj(sample);
-      // variance_[i] = decay_ * variance_[i] + (1.0f - decay_) * (
-      //  (sample - running_mean_[i]) * std::conj(sample -
-      //  running_mean_[i])).real();
       variance_[i] = (running_mean_sq_[i] -
                       running_mean_[i] * std::conj(running_mean_[i])).real();
     }
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h
index 9908ac0456..5013ef05d2 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.h
@@ -27,12 +27,6 @@ namespace intelligibility {
 // |limit|.
 float UpdateFactor(float target, float current, float limit);
 
-// std::isfinite for complex numbers.
-bool cplxfinite(std::complex<float> c);
-
-// std::isnormal for complex numbers.
-bool cplxnormal(std::complex<float> c);
-
 // Apply a small fudge to degenerate complex values. The numbers in the array
 // were chosen randomly, so that even a series of all zeroes has some small
 // variability.
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils_unittest.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils_unittest.cc
index ca5567cded..9caa2eb0a1 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils_unittest.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils_unittest.cc
@@ -48,20 +48,12 @@ TEST(IntelligibilityUtilsTest, TestUpdateFactor) {
   EXPECT_EQ(3, intelligibility::UpdateFactor(2, 4, 1));
 }
 
-// Tests cplxfinite, cplxnormal, and zerofudge.
+// Tests zerofudge.
 TEST(IntelligibilityUtilsTest, TestCplx) {
   complex<float> t0(1.f, 0.f);
-  EXPECT_TRUE(intelligibility::cplxfinite(t0));
-  EXPECT_FALSE(intelligibility::cplxnormal(t0));
   t0 = intelligibility::zerofudge(t0);
   EXPECT_NE(t0.imag(), 0.f);
   EXPECT_NE(t0.real(), 0.f);
-  const complex<float> t1(1.f, std::sqrt(-1.f));
-  EXPECT_FALSE(intelligibility::cplxfinite(t1));
-  EXPECT_FALSE(intelligibility::cplxnormal(t1));
-  const complex<float> t2(1.f, 1.f);
-  EXPECT_TRUE(intelligibility::cplxfinite(t2));
-  EXPECT_TRUE(intelligibility::cplxnormal(t2));
 }
 
 // Tests NewMean and AddToMean.