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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
/*
* Copyright (C) 2011 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DynamicsCompressor_h
#define DynamicsCompressor_h
#include "platform/audio/AudioArray.h"
#include "platform/audio/DynamicsCompressorKernel.h"
#include "wtf/Allocator.h"
#include "wtf/Noncopyable.h"
#include <memory>
namespace blink {
class AudioBus;
// DynamicsCompressor implements a flexible audio dynamics compression effect
// such as is commonly used in musical production and game audio. It lowers the
// volume of the loudest parts of the signal and raises the volume of the
// softest parts, making the sound richer, fuller, and more controlled.
class PLATFORM_EXPORT DynamicsCompressor {
USING_FAST_MALLOC(DynamicsCompressor);
WTF_MAKE_NONCOPYABLE(DynamicsCompressor);
public:
enum {
ParamThreshold,
ParamKnee,
ParamRatio,
ParamAttack,
ParamRelease,
ParamPreDelay,
ParamReleaseZone1,
ParamReleaseZone2,
ParamReleaseZone3,
ParamReleaseZone4,
ParamPostGain,
ParamFilterStageGain,
ParamFilterStageRatio,
ParamFilterAnchor,
ParamEffectBlend,
ParamReduction,
ParamLast
};
DynamicsCompressor(float sampleRate, unsigned numberOfChannels);
void process(const AudioBus* sourceBus,
AudioBus* destinationBus,
unsigned framesToProcess);
void reset();
void setNumberOfChannels(unsigned);
void setParameterValue(unsigned parameterID, float value);
float parameterValue(unsigned parameterID);
float sampleRate() const { return m_sampleRate; }
float nyquist() const { return m_sampleRate / 2; }
double tailTime() const { return 0; }
double latencyTime() const {
return m_compressor.latencyFrames() / static_cast<double>(sampleRate());
}
protected:
unsigned m_numberOfChannels;
// m_parameters holds the tweakable compressor parameters.
float m_parameters[ParamLast];
void initializeParameters();
float m_sampleRate;
// Emphasis filter controls.
float m_lastFilterStageRatio;
float m_lastAnchor;
float m_lastFilterStageGain;
std::unique_ptr<const float* []> m_sourceChannels;
std::unique_ptr<float* []> m_destinationChannels;
// The core compressor.
DynamicsCompressorKernel m_compressor;
};
} // namespace blink
#endif // DynamicsCompressor_h
|
