1/*
2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_VAD_PITCH_BASED_VAD_H_
12#define WEBRTC_MODULES_AUDIO_PROCESSING_VAD_PITCH_BASED_VAD_H_
13
14#include "webrtc/base/scoped_ptr.h"
15#include "webrtc/modules/audio_processing/vad/common.h"
16#include "webrtc/modules/audio_processing/vad/gmm.h"
17#include "webrtc/typedefs.h"
18
19namespace webrtc {
20
21class AudioFrame;
22class VadCircularBuffer;
23
24// Computes the probability of the input audio frame to be active given
25// the corresponding pitch-gain and lag of the frame.
26class PitchBasedVad {
27 public:
28  PitchBasedVad();
29  ~PitchBasedVad();
30
31  // Compute pitch-based voicing probability, given the features.
32  //   features: a structure containing features required for computing voicing
33  //             probabilities.
34  //
35  //   p_combined: an array which contains the combined activity probabilities
36  //               computed prior to the call of this function. The method,
37  //               then, computes the voicing probabilities and combine them
38  //               with the given values. The result are returned in |p|.
39  int VoicingProbability(const AudioFeatures& features, double* p_combined);
40
41 private:
42  int UpdatePrior(double p);
43
44  // TODO(turajs): maybe defining this at a higher level (maybe enum) so that
45  // all the code recognize it as "no-error."
46  static const int kNoError = 0;
47
48  GmmParameters noise_gmm_;
49  GmmParameters voice_gmm_;
50
51  double p_prior_;
52
53  rtc::scoped_ptr<VadCircularBuffer> circular_buffer_;
54};
55
56}  // namespace webrtc
57#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_VAD_PITCH_BASED_VAD_H_
58