agc.h revision ecf6b81644af9823dbff5c24a3d5b9bb596c0d5b 
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_AGC_AGC_H_
12#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_AGC_H_
13
14#include "webrtc/base/scoped_ptr.h"
15#include "webrtc/modules/audio_processing/vad/voice_activity_detector.h"
16#include "webrtc/typedefs.h"
17
18namespace webrtc {
19
20class AudioFrame;
21class Histogram;
22
23class Agc {
24 public:
25  Agc();
26  virtual ~Agc();
27
28  // Returns the proportion of samples in the buffer which are at full-scale
29  // (and presumably clipped).
30  virtual float AnalyzePreproc(const int16_t* audio, int length);
31  // |audio| must be mono; in a multi-channel stream, provide the first (usually
32  // left) channel.
33  virtual int Process(const int16_t* audio, int length, int sample_rate_hz);
34
35  // Retrieves the difference between the target RMS level and the current
36  // signal RMS level in dB. Returns true if an update is available and false
37  // otherwise, in which case |error| should be ignored and no action taken.
38  virtual bool GetRmsErrorDb(int* error);
39  virtual void Reset();
40
41  virtual int set_target_level_dbfs(int level);
42  virtual int target_level_dbfs() const { return target_level_dbfs_; }
43
44  virtual float voice_probability() const {
45    return vad_.last_voice_probability();
46  }
47
48 private:
49  double target_level_loudness_;
50  int target_level_dbfs_;
51  rtc::scoped_ptr<Histogram> histogram_;
52  rtc::scoped_ptr<Histogram> inactive_histogram_;
53  VoiceActivityDetector vad_;
54};
55
56}  // namespace webrtc
57
58#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_AGC_H_
59