content/media/webaudio/blink/DynamicsCompressor.h

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1 /*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #ifndef DynamicsCompressor_h
30 #define DynamicsCompressor_h
31
32 #include "DynamicsCompressorKernel.h"
33 #include "ZeroPole.h"
34
35 #include "nsTArray.h"
36 #include "nsAutoPtr.h"
37 #include "mozilla/MemoryReporting.h"
38
39 namespace mozilla {
40 struct AudioChunk;
41 }
42
43 namespace WebCore {
44
45 using mozilla::AudioChunk;
46
47 // DynamicsCompressor implements a flexible audio dynamics compression effect such as
48 // is commonly used in musical production and game audio. It lowers the volume
49 // of the loudest parts of the signal and raises the volume of the softest parts,
50 // making the sound richer, fuller, and more controlled.
51
52 class DynamicsCompressor {
53 public:
54 enum {
55 ParamThreshold,
56 ParamKnee,
57 ParamRatio,
58 ParamAttack,
59 ParamRelease,
60 ParamPreDelay,
61 ParamReleaseZone1,
62 ParamReleaseZone2,
63 ParamReleaseZone3,
64 ParamReleaseZone4,
65 ParamPostGain,
66 ParamFilterStageGain,
67 ParamFilterStageRatio,
68 ParamFilterAnchor,
69 ParamEffectBlend,
70 ParamReduction,
71 ParamLast
72 };
73
74 DynamicsCompressor(float sampleRate, unsigned numberOfChannels);
75
76 void process(const AudioChunk* sourceChunk, AudioChunk* destinationChunk, unsigned framesToProcess);
77 void reset();
78 void setNumberOfChannels(unsigned);
79 unsigned numberOfChannels() const { return m_numberOfChannels; }
80
81 void setParameterValue(unsigned parameterID, float value);
82 float parameterValue(unsigned parameterID);
83
84 float sampleRate() const { return m_sampleRate; }
85 float nyquist() const { return m_sampleRate / 2; }
86
87 double tailTime() const { return 0; }
88 double latencyTime() const { return m_compressor.latencyFrames() / static_cast<double>(sampleRate()); }
89
90 size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
91
92 protected:
93 unsigned m_numberOfChannels;
94
95 // m_parameters holds the tweakable compressor parameters.
96 float m_parameters[ParamLast];
97 void initializeParameters();
98
99 float m_sampleRate;
100
101 // Emphasis filter controls.
102 float m_lastFilterStageRatio;
103 float m_lastAnchor;
104 float m_lastFilterStageGain;
105
106 typedef struct {
107 ZeroPole filters[4];
108 size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
109 {
110 return aMallocSizeOf(this);
111 }
112 } ZeroPoleFilterPack4;
113
114 // Per-channel emphasis filters.
115 nsTArray<nsAutoPtr<ZeroPoleFilterPack4> > m_preFilterPacks;
116 nsTArray<nsAutoPtr<ZeroPoleFilterPack4> > m_postFilterPacks;
117
118 nsAutoArrayPtr<const float*> m_sourceChannels;
119 nsAutoArrayPtr<float*> m_destinationChannels;
120
121 void setEmphasisStageParameters(unsigned stageIndex, float gain, float normalizedFrequency /* 0 -> 1 */);
122 void setEmphasisParameters(float gain, float anchorFreq, float filterStageRatio);
123
124 // The core compressor.
125 DynamicsCompressorKernel m_compressor;
126 };
127
128 } // namespace WebCore
129
130 #endif // DynamicsCompressor_h

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