| // Copyright 2017 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef REMOTING_HOST_AUDIO_VOLUME_FILTER_H_ |
| #define REMOTING_HOST_AUDIO_VOLUME_FILTER_H_ |
| |
| #include "remoting/host/audio_silence_detector.h" |
| |
| namespace remoting { |
| |
| // A component to modify input audio sample to apply the audio level. This class |
| // is used on platforms which returns non-adjusted audio samples, e.g. Windows. |
| // This class supports frames with 16 bits per sample only. |
| class AudioVolumeFilter { |
| public: |
| // See AudioSilenceDetector for the meaning of |silence_threshold|. |
| explicit AudioVolumeFilter(int silence_threshold); |
| virtual ~AudioVolumeFilter(); |
| |
| // Adjusts audio samples in |data|. If the samples are silent before applying |
| // the volume level or the GetAudioLevel() returns 0, this function returns |
| // false. If |frames| is 0, this function also returns false. |
| bool Apply(int16_t* data, size_t frames); |
| |
| // Updates the sampling rate and channels. |
| void Initialize(int sampling_rate, int channels); |
| |
| protected: |
| // Returns the volume level in [0, 1]. This should be a normalized scalar |
| // value: sample values can be simply multiplied by the result of this |
| // function to apply volume. |
| virtual float GetAudioLevel() = 0; |
| |
| private: |
| AudioSilenceDetector silence_detector_; |
| }; |
| |
| } // namespace remoting |
| |
| #endif // REMOTING_HOST_AUDIO_VOLUME_FILTER_H_ |