1 /*
2  * Copyright (C) 2010 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:
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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.
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17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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27  */
28 
29 #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_REVERB_H_
30 #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_REVERB_H_
31 
32 #include <memory>
33 
34 #include "base/macros.h"
35 #include "third_party/blink/renderer/platform/audio/reverb_convolver.h"
36 #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
37 #include "third_party/blink/renderer/platform/wtf/vector.h"
38 
39 namespace blink {
40 
41 class AudioBus;
42 
43 // Multi-channel convolution reverb with channel matrixing - one or more
44 // ReverbConvolver objects are used internally.
45 
46 class PLATFORM_EXPORT Reverb {
47   USING_FAST_MALLOC(Reverb);
48 
49  public:
50   enum { kMaxFrameSize = 256 };
51 
52   // renderSliceSize is a rendering hint, so the FFTs can be optimized to not
53   // all occur at the same time (very bad when rendering on a real-time thread).
54   Reverb(AudioBus* impulse_response_buffer,
55          size_t render_slice_size,
56          size_t max_fft_size,
57          bool use_background_threads,
58          bool normalize);
59 
60   void Process(const AudioBus* source_bus,
61                AudioBus* destination_bus,
62                uint32_t frames_to_process);
63   void Reset();
64 
ImpulseResponseLength()65   size_t ImpulseResponseLength() const { return impulse_response_length_; }
66   size_t LatencyFrames() const;
67 
68  private:
69   void Initialize(AudioBus* impulse_response_buffer,
70                   size_t render_slice_size,
71                   size_t max_fft_size,
72                   bool use_background_threads,
73                   float scale);
74 
75   size_t impulse_response_length_;
76   // The actual number of channels in the response.  This can be less
77   // than the number of ReverbConvolver's in |m_convolvers|.
78   unsigned number_of_response_channels_;
79 
80   Vector<std::unique_ptr<ReverbConvolver>> convolvers_;
81 
82   // For "True" stereo processing
83   scoped_refptr<AudioBus> temp_buffer_;
84 
85   DISALLOW_COPY_AND_ASSIGN(Reverb);
86 };
87 
88 }  // namespace blink
89 
90 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_REVERB_H_
91