Move the aec_rdft* files to a more proper place beneath APM and make them thread-safe.

webrtc/modules/audio_processing/level_controller/signal_classifier.cc

 /*
  *  Copyright (c) 2016 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.
  */
 
 #include "webrtc/modules/audio_processing/level_controller/signal_classifier.h"
 
 #include <algorithm>
 #include <numeric>
 #include <vector>
 
 #include "webrtc/base/array_view.h"
 #include "webrtc/base/constructormagic.h"
-#include "webrtc/modules/audio_processing/aec/aec_rdft.h"
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 #include "webrtc/modules/audio_processing/level_controller/down_sampler.h"
 #include "webrtc/modules/audio_processing/level_controller/noise_spectrum_estimator.h"
 #include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
 
 namespace webrtc {
 namespace {
 
 void RemoveDcLevel(rtc::ArrayView<float> x) {
   RTC_DCHECK_LT(0u, x.size());
   float mean = std::accumulate(x.data(), x.data() + x.size(), 0.f);
   mean /= x.size();
 
   for (float& v : x) {
     v -= mean;
   }
 }
 
-void PowerSpectrum(rtc::ArrayView<const float> x,
+void PowerSpectrum(const OouraFft* ooura_fft,
+                   rtc::ArrayView<const float> x,
                    rtc::ArrayView<float> spectrum) {
   RTC_DCHECK_EQ(65u, spectrum.size());
   RTC_DCHECK_EQ(128u, x.size());
   float X[128];
   std::copy(x.data(), x.data() + x.size(), X);
-  aec_rdft_forward_128(X);
+  ooura_fft->Fft(X);
 
   float* X_p = X;
   RTC_DCHECK_EQ(X_p, &X[0]);
   spectrum[0] = (*X_p) * (*X_p);
   ++X_p;
   RTC_DCHECK_EQ(X_p, &X[1]);
   spectrum[64] = (*X_p) * (*X_p);
   for (int k = 1; k < 64; ++k) {
     ++X_p;
     RTC_DCHECK_EQ(X_p, &X[2 * k]);
@@ skipping 56 matching lines @@
 
 SignalClassifier::SignalClassifier(ApmDataDumper* data_dumper)
     : data_dumper_(data_dumper),
       down_sampler_(data_dumper_),
       noise_spectrum_estimator_(data_dumper_) {
   Initialize(AudioProcessing::kSampleRate48kHz);
 }
 SignalClassifier::~SignalClassifier() {}
 
 void SignalClassifier::Initialize(int sample_rate_hz) {
-  aec_rdft_init();
   down_sampler_.Initialize(sample_rate_hz);
   noise_spectrum_estimator_.Initialize();
   frame_extender_.reset(new FrameExtender(80, 128));
   sample_rate_hz_ = sample_rate_hz;
   initialization_frames_left_ = 2;
   consistent_classification_counter_ = 3;
   last_signal_type_ = SignalClassifier::SignalType::kNonStationary;
 }
 
 void SignalClassifier::Analyze(const AudioBuffer& audio,
                                SignalType* signal_type) {
   RTC_DCHECK_EQ(audio.num_frames(), static_cast<size_t>(sample_rate_hz_ / 100));
 
   // Compute the signal power spectrum.
   float downsampled_frame[80];
   down_sampler_.DownSample(rtc::ArrayView<const float>(
                                audio.channels_const_f()[0], audio.num_frames()),
                            downsampled_frame);
   float extended_frame[128];
   frame_extender_->ExtendFrame(downsampled_frame, extended_frame);
   RemoveDcLevel(extended_frame);
   float signal_spectrum[65];
-  PowerSpectrum(extended_frame, signal_spectrum);
+  PowerSpectrum(&ooura_fft_, extended_frame, signal_spectrum);
 
   // Classify the signal based on the estimate of the noise spectrum and the
   // signal spectrum estimate.
   *signal_type = ClassifySignal(signal_spectrum,
                                 noise_spectrum_estimator_.GetNoiseSpectrum(),
                                 data_dumper_);
 
   // Update the noise spectrum based on the signal spectrum.
   noise_spectrum_estimator_.Update(signal_spectrum,
                                    initialization_frames_left_ > 0);
 
   // Update the number of frames until a reliable signal spectrum is achieved.
   initialization_frames_left_ = std::max(0, initialization_frames_left_ - 1);
 
   if (last_signal_type_ == *signal_type) {
     consistent_classification_counter_ =
         std::max(0, consistent_classification_counter_ - 1);
   } else {
     last_signal_type_ = *signal_type;
     consistent_classification_counter_ = 3;
   }
 
   if (consistent_classification_counter_ > 0) {
     *signal_type = SignalClassifier::SignalType::kNonStationary;
   }
 }
 
 }  // namespace webrtc