1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
// Copyright 2017 The Chromium Authors
// 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_
|
