xref: /aosp_15_r20/external/webrtc/modules/audio_processing/gain_controller2.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright (c) 2017 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_GAIN_CONTROLLER2_H_
12 #define MODULES_AUDIO_PROCESSING_GAIN_CONTROLLER2_H_
13 
14 #include <atomic>
15 #include <memory>
16 #include <string>
17 
18 #include "modules/audio_processing/agc2/adaptive_digital_gain_controller.h"
19 #include "modules/audio_processing/agc2/cpu_features.h"
20 #include "modules/audio_processing/agc2/gain_applier.h"
21 #include "modules/audio_processing/agc2/input_volume_controller.h"
22 #include "modules/audio_processing/agc2/limiter.h"
23 #include "modules/audio_processing/agc2/vad_wrapper.h"
24 #include "modules/audio_processing/include/audio_processing.h"
25 #include "modules/audio_processing/logging/apm_data_dumper.h"
26 
27 namespace webrtc {
28 
29 class AudioBuffer;
30 
31 // Gain Controller 2 aims to automatically adjust levels by acting on the
32 // microphone gain and/or applying digital gain.
33 class GainController2 {
34  public:
35   // Ctor. If `use_internal_vad` is true, an internal voice activity
36   // detector is used for digital adaptive gain.
37   GainController2(
38       const AudioProcessing::Config::GainController2& config,
39       const InputVolumeController::Config& input_volume_controller_config,
40       int sample_rate_hz,
41       int num_channels,
42       bool use_internal_vad);
43   GainController2(const GainController2&) = delete;
44   GainController2& operator=(const GainController2&) = delete;
45   ~GainController2();
46 
47   // Sets the fixed digital gain.
48   void SetFixedGainDb(float gain_db);
49 
50   // Updates the input volume controller about whether the capture output is
51   // used or not.
52   void SetCaptureOutputUsed(bool capture_output_used);
53 
54   // Analyzes `audio_buffer` before `Process()` is called so that the analysis
55   // can be performed before digital processing operations take place (e.g.,
56   // echo cancellation). The analysis consists of input clipping detection and
57   // prediction (if enabled). The value of `applied_input_volume` is limited to
58   // [0, 255].
59   void Analyze(int applied_input_volume, const AudioBuffer& audio_buffer);
60 
61   // Applies fixed and adaptive digital gains to `audio` and runs a limiter.
62   // If the internal VAD is used, `speech_probability` is ignored. Otherwise
63   // `speech_probability` is used for digital adaptive gain if it's available
64   // (limited to values [0.0, 1.0]). Handles input volume changes; if the caller
65   // cannot determine whether an input volume change occurred, set
66   // `input_volume_changed` to false.
67   void Process(absl::optional<float> speech_probability,
68                bool input_volume_changed,
69                AudioBuffer* audio);
70 
71   static bool Validate(const AudioProcessing::Config::GainController2& config);
72 
GetCpuFeatures()73   AvailableCpuFeatures GetCpuFeatures() const { return cpu_features_; }
74 
75   // Returns the recommended input volume if input volume controller is enabled
76   // and if a volume recommendation is available.
77   absl::optional<int> GetRecommendedInputVolume() const;
78 
79  private:
80   static std::atomic<int> instance_count_;
81   const AvailableCpuFeatures cpu_features_;
82   ApmDataDumper data_dumper_;
83   GainApplier fixed_gain_applier_;
84   std::unique_ptr<VoiceActivityDetectorWrapper> vad_;
85   std::unique_ptr<AdaptiveDigitalGainController> adaptive_digital_controller_;
86   std::unique_ptr<InputVolumeController> input_volume_controller_;
87   Limiter limiter_;
88   int calls_since_last_limiter_log_;
89 };
90 
91 }  // namespace webrtc
92 
93 #endif  // MODULES_AUDIO_PROCESSING_GAIN_CONTROLLER2_H_
94