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 MODULES_AUDIO_PROCESSING_AGC_AGC_H_
12 #define MODULES_AUDIO_PROCESSING_AGC_AGC_H_
13 
14 #include <memory>
15 
16 #include "modules/audio_processing/vad/voice_activity_detector.h"
17 
18 namespace webrtc {
19 
20 class LoudnessHistogram;
21 
22 class Agc {
23  public:
24   Agc();
25   virtual ~Agc();
26 
27   // |audio| must be mono; in a multi-channel stream, provide the first (usually
28   // left) channel.
29   virtual void Process(const int16_t* audio, size_t length, int sample_rate_hz);
30 
31   // Retrieves the difference between the target RMS level and the current
32   // signal RMS level in dB. Returns true if an update is available and false
33   // otherwise, in which case |error| should be ignored and no action taken.
34   virtual bool GetRmsErrorDb(int* error);
35   virtual void Reset();
36 
37   virtual int set_target_level_dbfs(int level);
38   virtual int target_level_dbfs() const;
39   virtual float voice_probability() const;
40 
41  private:
42   double target_level_loudness_;
43   int target_level_dbfs_;
44   std::unique_ptr<LoudnessHistogram> histogram_;
45   std::unique_ptr<LoudnessHistogram> inactive_histogram_;
46   VoiceActivityDetector vad_;
47 };
48 
49 }  // namespace webrtc
50 
51 #endif  // MODULES_AUDIO_PROCESSING_AGC_AGC_H_
52