Pull the Voice Activity Detector out from the AGC

webrtc/modules/audio_processing/agc/pitch_based_vad.h

-/*
- *  Copyright (c) 2012 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.
- */
-
-#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_PITCH_BASED_VAD_H_
-#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_PITCH_BASED_VAD_H_
-
-#include "webrtc/base/scoped_ptr.h"
-#include "webrtc/modules/audio_processing/agc/common.h"
-#include "webrtc/modules/audio_processing/agc/gmm.h"
-#include "webrtc/typedefs.h"
-
-namespace webrtc {
-
-class AudioFrame;
-class AgcCircularBuffer;
-
-// Computes the probability of the input audio frame to be active given
-// the corresponding pitch-gain and lag of the frame.
-class PitchBasedVad {
- public:
-  PitchBasedVad();
-  ~PitchBasedVad();
-
-  // Compute pitch-based voicing probability, given the features.
-  //   features: a structure containing features required for computing voicing
-  //             probabilities.
-  //
-  //   p_combined: an array which contains the combined activity probabilities
-  //               computed prior to the call of this function. The method,
-  //               then, computes the voicing probabilities and combine them
-  //               with the given values. The result are returned in |p|.
-  int VoicingProbability(const AudioFeatures& features, double* p_combined);
- private:
-  int UpdatePrior(double p);
-
-  // TODO(turajs): maybe defining this at a higher level (maybe enum) so that
-  // all the code recognize it as "no-error."
-  static const int kNoError = 0;
-
-  GmmParameters noise_gmm_;
-  GmmParameters voice_gmm_;
-
-  double p_prior_;
-
-  rtc::scoped_ptr<AgcCircularBuffer> circular_buffer_;
-};
-
-}  // namespace webrtc
-#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_PITCH_BASED_VAD_H_