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 "AudioBasicProcessorNode.h"
30
31#include "AudioBus.h"
32#include "AudioContext.h"
33#include "AudioNodeInput.h"
34#include "AudioNodeOutput.h"
35#include "AudioProcessor.h"
36
37namespace WebCore {
38
39AudioBasicProcessorNode::AudioBasicProcessorNode(AudioContext* context, float sampleRate)
40    : AudioNode(context, sampleRate)
41{
42    addInput(std::make_unique<AudioNodeInput>(this));
43    addOutput(std::make_unique<AudioNodeOutput>(this, 1));
44
45    // The subclass must create m_processor.
46}
47
48void AudioBasicProcessorNode::initialize()
49{
50    if (isInitialized())
51        return;
52
53    ASSERT(processor());
54    processor()->initialize();
55
56    AudioNode::initialize();
57}
58
59void AudioBasicProcessorNode::uninitialize()
60{
61    if (!isInitialized())
62        return;
63
64    ASSERT(processor());
65    processor()->uninitialize();
66
67    AudioNode::uninitialize();
68}
69
70void AudioBasicProcessorNode::process(size_t framesToProcess)
71{
72    AudioBus* destinationBus = output(0)->bus();
73
74    if (!isInitialized() || !processor() || processor()->numberOfChannels() != numberOfChannels())
75        destinationBus->zero();
76    else {
77        AudioBus* sourceBus = input(0)->bus();
78
79        // FIXME: if we take "tail time" into account, then we can avoid calling processor()->process() once the tail dies down.
80        if (!input(0)->isConnected())
81            sourceBus->zero();
82
83        processor()->process(sourceBus, destinationBus, framesToProcess);
84    }
85}
86
87// Nice optimization in the very common case allowing for "in-place" processing
88void AudioBasicProcessorNode::pullInputs(size_t framesToProcess)
89{
90    // Render input stream - suggest to the input to render directly into output bus for in-place processing in process() if possible.
91    input(0)->pull(output(0)->bus(), framesToProcess);
92}
93
94void AudioBasicProcessorNode::reset()
95{
96    if (processor())
97        processor()->reset();
98}
99
100// As soon as we know the channel count of our input, we can lazily initialize.
101// Sometimes this may be called more than once with different channel counts, in which case we must safely
102// uninitialize and then re-initialize with the new channel count.
103void AudioBasicProcessorNode::checkNumberOfChannelsForInput(AudioNodeInput* input)
104{
105    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
106
107    ASSERT(input == this->input(0));
108    if (input != this->input(0))
109        return;
110
111    ASSERT(processor());
112    if (!processor())
113        return;
114
115    unsigned numberOfChannels = input->numberOfChannels();
116
117    if (isInitialized() && numberOfChannels != output(0)->numberOfChannels()) {
118        // We're already initialized but the channel count has changed.
119        uninitialize();
120    }
121
122    if (!isInitialized()) {
123        // This will propagate the channel count to any nodes connected further down the chain...
124        output(0)->setNumberOfChannels(numberOfChannels);
125
126        // Re-initialize the processor with the new channel count.
127        processor()->setNumberOfChannels(numberOfChannels);
128        initialize();
129    }
130
131    AudioNode::checkNumberOfChannelsForInput(input);
132}
133
134unsigned AudioBasicProcessorNode::numberOfChannels()
135{
136    return output(0)->numberOfChannels();
137}
138
139double AudioBasicProcessorNode::tailTime() const
140{
141    return m_processor->tailTime();
142}
143
144double AudioBasicProcessorNode::latencyTime() const
145{
146    return m_processor->latencyTime();
147}
148
149} // namespace WebCore
150
151#endif // ENABLE(WEB_AUDIO)
152