1 /*
2  *  Copyright (c) 2018 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_AGC2_GAIN_APPLIER_H_
12 #define MODULES_AUDIO_PROCESSING_AGC2_GAIN_APPLIER_H_
13 
14 #include <stddef.h>
15 
16 #include "modules/audio_processing/include/audio_frame_view.h"
17 
18 namespace webrtc {
19 class GainApplier {
20  public:
21   GainApplier(bool hard_clip_samples, float initial_gain_factor);
22 
23   void ApplyGain(AudioFrameView<float> signal);
24   void SetGainFactor(float gain_factor);
GetGainFactor()25   float GetGainFactor() const { return current_gain_factor_; }
26 
27  private:
28   void Initialize(size_t samples_per_channel);
29 
30   // Whether to clip samples after gain is applied. If 'true', result
31   // will fit in FloatS16 range.
32   const bool hard_clip_samples_;
33   float last_gain_factor_;
34 
35   // If this value is not equal to 'last_gain_factor', gain will be
36   // ramped from 'last_gain_factor_' to this value during the next
37   // 'ApplyGain'.
38   float current_gain_factor_;
39   int samples_per_channel_ = -1;
40   float inverse_samples_per_channel_ = -1.f;
41 };
42 }  // namespace webrtc
43 
44 #endif  // MODULES_AUDIO_PROCESSING_AGC2_GAIN_APPLIER_H_
45