Add new variance update option and unittests for intelligibility

webrtc/modules/audio_processing/intelligibility/intelligibility_enhancer.h

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.

[hlundin-webrtc, 2015/07/02 10:53:13]

2015

In fact, I believe all the files in
webrtc/modules/audio_processing/intelligibility/ were created in 2015, and
should be dated such. Please, fix.

[ekm, 2015/07/07 21:57:02]

intelligibility_enhancer, _utils, and _proc existed in the old internal repo
where they were added in 2014. Should I still change to 2015 since that's when
they were added to the current repo?

  *
  *  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.
  */
 
 //
 //  Specifies core class for intelligbility enhancement.
@@ skipping 63 matching lines @@
                                    int in_channels,
                                    int frames,
                                    int out_channels,
                                    std::complex<float>* const* out_block);
 
    private:
     IntelligibilityEnhancer* parent_;
     AudioSource source_;
   };
   friend class TransformCallback;
+  FRIEND_TEST_ALL_PREFIXES(IntelligibilityEnhancerTest, TestErbCreation);
+  FRIEND_TEST_ALL_PREFIXES(IntelligibilityEnhancerTest, TestSolveForGains);
 
   // Sends streams to ProcessClearBlock or ProcessNoiseBlock based on source.
   void DispatchAudio(AudioSource source,
                      const std::complex<float>* in_block,
                      std::complex<float>* out_block);
 
   // Updates variance computation and analysis with |in_block_|,
   // and writes modified speech to |out_block|.
   void ProcessClearBlock(const std::complex<float>* in_block,
                          std::complex<float>* out_block);
 
   // Computes and sets modified gains.
   void AnalyzeClearBlock(float power_target);
 
+  // Bisection search for optimal |lambda|.
+  void SolveForLambda(float power_target, float power_bot, float power_top);
+
+  // Transforms freq gains to ERB gains.
+  void UpdateErbGains();
+
   // Updates variance calculation for noise input with |in_block|.
   void ProcessNoiseBlock(const std::complex<float>* in_block,
                          std::complex<float>* out_block);
 
   // Returns number of ERB filters.
   static int GetBankSize(int sample_rate, int erb_resolution);
 
   // Initializes ERB filterbank.
   void CreateErbBank();
 
   // Analytically solves quadratic for optimal gains given |lambda|.
   // Negative gains are set to 0. Stores the results in |sols|.
   void SolveForGainsGivenLambda(float lambda, int start_freq, float* sols);
 
   // Computes variance across ERB filters from freq variance |var|.
   // Stores in |result|.
   void FilterVariance(const float* var, float* result);
 
   // Returns dot product of vectors specified by size |length| arrays |a|,|b|.
   static float DotProduct(const float* a, const float* b, int length);
 
-  static const int kErbResolution;
-  static const int kWindowSizeMs;
-  static const int kChunkSizeMs;
-  static const int kAnalyzeRate;   // Default for |analysis_rate_|.
-  static const int kVarianceRate;  // Default for |variance_rate_|.
-  static const float kClipFreq;
-  static const float kConfigRho;  // Default production and interpretation SNR.
-  static const float kKbdAlpha;
-  static const float kGainChangeLimit;
-
   const int freqs_;         // Num frequencies in frequency domain.
   const int window_size_;   // Window size in samples; also the block size.
   const int chunk_length_;  // Chunk size in samples.
   const int bank_size_;     // Num ERB filters.
   const int sample_rate_hz_;
   const int erb_resolution_;
   const int channels_;       // Num channels.
   const int analysis_rate_;  // Num blocks before gains recalculated.
   const int variance_rate_;  // Num recalculations before history is cleared.
 
@@ skipping 28 matching lines @@
   // Note: VAD currently does not affect anything in IntelligibilityEnhancer.
   VadInst* vad_high_;
   VadInst* vad_low_;
   rtc::scoped_ptr<int16_t[]> vad_tmp_buffer_;
   bool has_voice_low_;  // Whether voice detected in speech stream.
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_INTELLIGIBILITY_INTELLIGIBILITY_ENHANCER_H_