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 "modules/webaudio/AudioBasicProcessorNode.h"
30
31#include "platform/audio/AudioBus.h"
32#include "platform/audio/AudioProcessor.h"
33#include "modules/webaudio/AudioContext.h"
34#include "modules/webaudio/AudioNodeInput.h"
35#include "modules/webaudio/AudioNodeOutput.h"
36
37namespace blink {
38
39AudioBasicProcessorNode::AudioBasicProcessorNode(AudioContext* context, float sampleRate)
40    : AudioNode(context, sampleRate)
41{
42    addInput();
43    addOutput(AudioNodeOutput::create(this, 1));
44
45    // The subclass must create m_processor.
46}
47
48AudioBasicProcessorNode::~AudioBasicProcessorNode()
49{
50    ASSERT(!isInitialized());
51}
52
53void AudioBasicProcessorNode::trace(Visitor* visitor)
54{
55    visitor->trace(m_processor);
56    AudioNode::trace(visitor);
57}
58
59void AudioBasicProcessorNode::dispose()
60{
61    uninitialize();
62    AudioNode::dispose();
63}
64
65void AudioBasicProcessorNode::initialize()
66{
67    if (isInitialized())
68        return;
69
70    ASSERT(processor());
71    processor()->initialize();
72
73    AudioNode::initialize();
74}
75
76void AudioBasicProcessorNode::uninitialize()
77{
78    if (!isInitialized())
79        return;
80
81    ASSERT(processor());
82    processor()->uninitialize();
83
84    AudioNode::uninitialize();
85}
86
87void AudioBasicProcessorNode::process(size_t framesToProcess)
88{
89    AudioBus* destinationBus = output(0)->bus();
90
91    if (!isInitialized() || !processor() || processor()->numberOfChannels() != numberOfChannels())
92        destinationBus->zero();
93    else {
94        AudioBus* sourceBus = input(0)->bus();
95
96        // FIXME: if we take "tail time" into account, then we can avoid calling processor()->process() once the tail dies down.
97        if (!input(0)->isConnected())
98            sourceBus->zero();
99
100        processor()->process(sourceBus, destinationBus, framesToProcess);
101    }
102}
103
104// Nice optimization in the very common case allowing for "in-place" processing
105void AudioBasicProcessorNode::pullInputs(size_t framesToProcess)
106{
107    // Render input stream - suggest to the input to render directly into output bus for in-place processing in process() if possible.
108    input(0)->pull(output(0)->bus(), framesToProcess);
109}
110
111// As soon as we know the channel count of our input, we can lazily initialize.
112// Sometimes this may be called more than once with different channel counts, in which case we must safely
113// uninitialize and then re-initialize with the new channel count.
114void AudioBasicProcessorNode::checkNumberOfChannelsForInput(AudioNodeInput* input)
115{
116    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
117
118    ASSERT(input == this->input(0));
119    if (input != this->input(0))
120        return;
121
122    ASSERT(processor());
123    if (!processor())
124        return;
125
126    unsigned numberOfChannels = input->numberOfChannels();
127
128    if (isInitialized() && numberOfChannels != output(0)->numberOfChannels()) {
129        // We're already initialized but the channel count has changed.
130        uninitialize();
131    }
132
133    if (!isInitialized()) {
134        // This will propagate the channel count to any nodes connected further down the chain...
135        output(0)->setNumberOfChannels(numberOfChannels);
136
137        // Re-initialize the processor with the new channel count.
138        processor()->setNumberOfChannels(numberOfChannels);
139        initialize();
140    }
141
142    AudioNode::checkNumberOfChannelsForInput(input);
143}
144
145unsigned AudioBasicProcessorNode::numberOfChannels()
146{
147    return output(0)->numberOfChannels();
148}
149
150double AudioBasicProcessorNode::tailTime() const
151{
152    return m_processor->tailTime();
153}
154
155double AudioBasicProcessorNode::latencyTime() const
156{
157    return m_processor->latencyTime();
158}
159
160} // namespace blink
161
162#endif // ENABLE(WEB_AUDIO)
163