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: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY |
14 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
16 | * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
17 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
18 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
19 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
20 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
22 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
23 | */ |
24 | |
25 | #include "config.h" |
26 | |
27 | #if ENABLE(WEB_AUDIO) |
28 | |
29 | #include "GainNode.h" |
30 | |
31 | #include "AudioBus.h" |
32 | #include "AudioNodeInput.h" |
33 | #include "AudioNodeOutput.h" |
34 | #include <wtf/IsoMallocInlines.h> |
35 | |
36 | namespace WebCore { |
37 | |
38 | WTF_MAKE_ISO_ALLOCATED_IMPL(GainNode); |
39 | |
40 | GainNode::GainNode(AudioContext& context, float sampleRate) |
41 | : AudioNode(context, sampleRate) |
42 | , m_lastGain(1.0) |
43 | , m_sampleAccurateGainValues(AudioNode::ProcessingSizeInFrames) // FIXME: can probably share temp buffer in context |
44 | { |
45 | setNodeType(NodeTypeGain); |
46 | |
47 | m_gain = AudioParam::create(context, "gain" , 1.0, 0.0, 1.0); |
48 | |
49 | addInput(std::make_unique<AudioNodeInput>(this)); |
50 | addOutput(std::make_unique<AudioNodeOutput>(this, 1)); |
51 | |
52 | initialize(); |
53 | } |
54 | |
55 | void GainNode::process(size_t framesToProcess) |
56 | { |
57 | // FIXME: for some cases there is a nice optimization to avoid processing here, and let the gain change |
58 | // happen in the summing junction input of the AudioNode we're connected to. |
59 | // Then we can avoid all of the following: |
60 | |
61 | AudioBus* outputBus = output(0)->bus(); |
62 | ASSERT(outputBus); |
63 | |
64 | if (!isInitialized() || !input(0)->isConnected()) |
65 | outputBus->zero(); |
66 | else { |
67 | AudioBus* inputBus = input(0)->bus(); |
68 | |
69 | if (gain()->hasSampleAccurateValues()) { |
70 | // Apply sample-accurate gain scaling for precise envelopes, grain windows, etc. |
71 | ASSERT(framesToProcess <= m_sampleAccurateGainValues.size()); |
72 | if (framesToProcess <= m_sampleAccurateGainValues.size()) { |
73 | float* gainValues = m_sampleAccurateGainValues.data(); |
74 | gain()->calculateSampleAccurateValues(gainValues, framesToProcess); |
75 | outputBus->copyWithSampleAccurateGainValuesFrom(*inputBus, gainValues, framesToProcess); |
76 | } |
77 | } else { |
78 | // Apply the gain with de-zippering into the output bus. |
79 | if (!m_lastGain && m_lastGain == m_gain->value()) { |
80 | // If the gain is 0 (and we've converged on dezippering), just zero the bus and set |
81 | // the silence hint. |
82 | outputBus->zero(); |
83 | } else |
84 | outputBus->copyWithGainFrom(*inputBus, &m_lastGain, gain()->value()); |
85 | } |
86 | } |
87 | } |
88 | |
89 | void GainNode::reset() |
90 | { |
91 | // Snap directly to desired gain. |
92 | m_lastGain = gain()->value(); |
93 | } |
94 | |
95 | // FIXME: this can go away when we do mixing with gain directly in summing junction of AudioNodeInput |
96 | // |
97 | // As soon as we know the channel count of our input, we can lazily initialize. |
98 | // Sometimes this may be called more than once with different channel counts, in which case we must safely |
99 | // uninitialize and then re-initialize with the new channel count. |
100 | void GainNode::checkNumberOfChannelsForInput(AudioNodeInput* input) |
101 | { |
102 | ASSERT(context().isAudioThread() && context().isGraphOwner()); |
103 | |
104 | ASSERT(input && input == this->input(0)); |
105 | if (input != this->input(0)) |
106 | return; |
107 | |
108 | unsigned numberOfChannels = input->numberOfChannels(); |
109 | |
110 | if (isInitialized() && numberOfChannels != output(0)->numberOfChannels()) { |
111 | // We're already initialized but the channel count has changed. |
112 | uninitialize(); |
113 | } |
114 | |
115 | if (!isInitialized()) { |
116 | // This will propagate the channel count to any nodes connected further downstream in the graph. |
117 | output(0)->setNumberOfChannels(numberOfChannels); |
118 | initialize(); |
119 | } |
120 | |
121 | AudioNode::checkNumberOfChannelsForInput(input); |
122 | } |
123 | |
124 | } // namespace WebCore |
125 | |
126 | #endif // ENABLE(WEB_AUDIO) |
127 | |