Integrate Intelligibility with APM

webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 48 matching lines @@
   return mean + (data - mean) / static_cast<float>(count);
 }
 
 void AddToMean(complex<float> data, int count, complex<float>* mean) {
   (*mean) = NewMean(*mean, data, count);
 }
 
 
 static const int kWindowBlockSize = 10;
 
-VarianceArray::VarianceArray(int freqs,
+VarianceArray::VarianceArray(int num_freqs,
                              StepType type,
                              int window_size,
                              float decay)
-    : running_mean_(new complex<float>[freqs]()),
-      running_mean_sq_(new complex<float>[freqs]()),
-      sub_running_mean_(new complex<float>[freqs]()),
-      sub_running_mean_sq_(new complex<float>[freqs]()),
-      variance_(new float[freqs]()),
-      conj_sum_(new float[freqs]()),
-      freqs_(freqs),
+    : running_mean_(new complex<float>[num_freqs]()),
+      running_mean_sq_(new complex<float>[num_freqs]()),
+      sub_running_mean_(new complex<float>[num_freqs]()),
+      sub_running_mean_sq_(new complex<float>[num_freqs]()),
+      variance_(new float[num_freqs]()),
+      conj_sum_(new float[num_freqs]()),
+      num_freqs_(num_freqs),
       window_size_(window_size),
       decay_(decay),
       history_cursor_(0),
       count_(0),
       array_mean_(0.0f),
       buffer_full_(false) {
-  history_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]());
-  for (int i = 0; i < freqs_; ++i) {
+  history_.reset(new rtc::scoped_ptr<complex<float>[]>[num_freqs_]());
+  for (int i = 0; i < num_freqs_; ++i) {
     history_[i].reset(new complex<float>[window_size_]());
   }
-  subhistory_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]());
-  for (int i = 0; i < freqs_; ++i) {
+  subhistory_.reset(new rtc::scoped_ptr<complex<float>[]>[num_freqs_]());
+  for (int i = 0; i < num_freqs_; ++i) {
     subhistory_[i].reset(new complex<float>[window_size_]());
   }
-  subhistory_sq_.reset(new rtc::scoped_ptr<complex<float>[]>[freqs_]());
-  for (int i = 0; i < freqs_; ++i) {
+  subhistory_sq_.reset(new rtc::scoped_ptr<complex<float>[]>[num_freqs_]());
+  for (int i = 0; i < num_freqs_; ++i) {
     subhistory_sq_[i].reset(new complex<float>[window_size_]());
   }
   switch (type) {
     case kStepInfinite:
       step_func_ = &VarianceArray::InfiniteStep;
       break;
     case kStepDecaying:
       step_func_ = &VarianceArray::DecayStep;
       break;
     case kStepWindowed:
       step_func_ = &VarianceArray::WindowedStep;
       break;
     case kStepBlocked:
       step_func_ = &VarianceArray::BlockedStep;
       break;
     case kStepBlockBasedMovingAverage:
       step_func_ = &VarianceArray::BlockBasedMovingAverage;
       break;
   }
 }
 
 // Compute the variance with Welford's algorithm, adding some fudge to
 // the input in case of all-zeroes.
 void VarianceArray::InfiniteStep(const complex<float>* data, bool skip_fudge) {
   array_mean_ = 0.0f;
   ++count_;
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     complex<float> sample = data[i];
     if (!skip_fudge) {
       sample = zerofudge(sample);
     }
     if (count_ == 1) {
       running_mean_[i] = sample;
       variance_[i] = 0.0f;
     } else {
       float old_sum = conj_sum_[i];
       complex<float> old_mean = running_mean_[i];
@@ skipping 10 matching lines @@
     }
     array_mean_ += (variance_[i] - array_mean_) / (i + 1);
   }
 }
 
 // Compute the variance from the beginning, with exponential decaying of the
 // series data.
 void VarianceArray::DecayStep(const complex<float>* data, bool /*dummy*/) {
   array_mean_ = 0.0f;
   ++count_;
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     complex<float> sample = data[i];
     sample = zerofudge(sample);
 
     if (count_ == 1) {
       running_mean_[i] = sample;
       running_mean_sq_[i] = sample * std::conj(sample);
       variance_[i] = 0.0f;
     } else {
       complex<float> prev = running_mean_[i];
       complex<float> prev2 = running_mean_sq_[i];
       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();
     }
 
     array_mean_ += (variance_[i] - array_mean_) / (i + 1);
   }
 }
 
 // Windowed variance computation. On each step, the variances for the
 // window are recomputed from scratch, using Welford's algorithm.
 void VarianceArray::WindowedStep(const complex<float>* data, bool /*dummy*/) {
   int num = min(count_ + 1, window_size_);
   array_mean_ = 0.0f;
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     complex<float> mean;
     float conj_sum = 0.0f;
 
     history_[i][history_cursor_] = data[i];
 
     mean = history_[i][history_cursor_];
     variance_[i] = 0.0f;
     for (int j = 1; j < num; ++j) {
       complex<float> sample =
           zerofudge(history_[i][(history_cursor_ + j) % window_size_]);
@@ skipping 12 matching lines @@
   ++count_;
 }
 
 // Variance with a window of blocks. Within each block, the variances are
 // recomputed from scratch at every stp, using |Var(X) = E(X^2) - E^2(X)|.
 // Once a block is filled with kWindowBlockSize samples, it is added to the
 // history window and a new block is started. The variances for the window
 // are recomputed from scratch at each of these transitions.
 void VarianceArray::BlockedStep(const complex<float>* data, bool /*dummy*/) {
   int blocks = min(window_size_, history_cursor_ + 1);
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     AddToMean(data[i], count_ + 1, &sub_running_mean_[i]);
     AddToMean(data[i] * std::conj(data[i]), count_ + 1,
               &sub_running_mean_sq_[i]);
     subhistory_[i][history_cursor_ % window_size_] = sub_running_mean_[i];
     subhistory_sq_[i][history_cursor_ % window_size_] = sub_running_mean_sq_[i];
 
     variance_[i] =
         (NewMean(running_mean_sq_[i], sub_running_mean_sq_[i], blocks) -
          NewMean(running_mean_[i], sub_running_mean_[i], blocks) *
              std::conj(NewMean(running_mean_[i], sub_running_mean_[i], blocks)))
@@ skipping 15 matching lines @@
     count_ = 0;
   }
 }
 
 // Recomputes variances for each window from scratch based on previous window.
 void VarianceArray::BlockBasedMovingAverage(const std::complex<float>* data,
                                             bool /*dummy*/) {
   // TODO(ekmeyerson) To mitigate potential divergence, add counter so that
   // after every so often sums are computed scratch by summing over all
   // elements instead of subtracting oldest and adding newest.
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     sub_running_mean_[i] += data[i];
     sub_running_mean_sq_[i] += data[i] * std::conj(data[i]);
   }
   ++count_;
 
   // TODO(ekmeyerson) Make kWindowBlockSize nonconstant to allow
   // experimentation with different block size,window size pairs.
   if (count_ >= kWindowBlockSize) {
     count_ = 0;
 
-    for (int i = 0; i < freqs_; ++i) {
+    for (int i = 0; i < num_freqs_; ++i) {
       running_mean_[i] -= subhistory_[i][history_cursor_];
       running_mean_sq_[i] -= subhistory_sq_[i][history_cursor_];
 
       float scale = 1.f / kWindowBlockSize;
       subhistory_[i][history_cursor_] = sub_running_mean_[i] * scale;
       subhistory_sq_[i][history_cursor_] = sub_running_mean_sq_[i] * scale;
 
       sub_running_mean_[i] = std::complex<float>(0.0f, 0.0f);
       sub_running_mean_sq_[i] = std::complex<float>(0.0f, 0.0f);
 
       running_mean_[i] += subhistory_[i][history_cursor_];
       running_mean_sq_[i] += subhistory_sq_[i][history_cursor_];
 
       scale = 1.f / (buffer_full_ ? window_size_ : history_cursor_ + 1);
       variance_[i] = std::real(running_mean_sq_[i] * scale -
                                running_mean_[i] * scale *
                                    std::conj(running_mean_[i]) * scale);
     }
 
     ++history_cursor_;
     if (history_cursor_ >= window_size_) {
       buffer_full_ = true;
       history_cursor_ = 0;
     }
   }
 }
 
 void VarianceArray::Clear() {
-  memset(running_mean_.get(), 0, sizeof(*running_mean_.get()) * freqs_);
-  memset(running_mean_sq_.get(), 0, sizeof(*running_mean_sq_.get()) * freqs_);
-  memset(variance_.get(), 0, sizeof(*variance_.get()) * freqs_);
-  memset(conj_sum_.get(), 0, sizeof(*conj_sum_.get()) * freqs_);
+  memset(running_mean_.get(), 0, sizeof(*running_mean_.get()) * num_freqs_);
+  memset(running_mean_sq_.get(), 0,
+         sizeof(*running_mean_sq_.get()) * num_freqs_);
+  memset(variance_.get(), 0, sizeof(*variance_.get()) * num_freqs_);
+  memset(conj_sum_.get(), 0, sizeof(*conj_sum_.get()) * num_freqs_);
   history_cursor_ = 0;
   count_ = 0;
   array_mean_ = 0.0f;
 }
 
 void VarianceArray::ApplyScale(float scale) {
   array_mean_ = 0.0f;
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     variance_[i] *= scale * scale;
     array_mean_ += (variance_[i] - array_mean_) / (i + 1);
   }
 }
 
 GainApplier::GainApplier(int freqs, float change_limit)
-    : freqs_(freqs),
+    : num_freqs_(freqs),
       change_limit_(change_limit),
       target_(new float[freqs]()),
       current_(new float[freqs]()) {
   for (int i = 0; i < freqs; ++i) {
     target_[i] = 1.0f;
     current_[i] = 1.0f;
   }
 }
 
 void GainApplier::Apply(const complex<float>* in_block,
                         complex<float>* out_block) {
-  for (int i = 0; i < freqs_; ++i) {
+  for (int i = 0; i < num_freqs_; ++i) {
     float factor = sqrtf(fabsf(current_[i]));
     if (!std::isnormal(factor)) {
       factor = 1.0f;
     }
     out_block[i] = factor * in_block[i];
     current_[i] = UpdateFactor(target_[i], current_[i], change_limit_);
   }
 }
 
+void GainApplier::Clear() {
+  for (int i = 0; i < num_freqs_; ++i) {
+    target_[i] = 1.f;
+  }
+}
+
+// TODO(ekmeyerson): Can reduce from O(|num_freqs_|) to O(1) if necessary.
+bool GainApplier::IsIdentity() {
+  for (int i = 0; i < num_freqs_; ++i) {
+    if (current_[i] != 1.f || target_[i] != 1.f) {
+      return false;
+    }
+  }
+  return true;
+}
+
 }  // namespace intelligibility
 
 }  // namespace webrtc