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, double sampleRate)
40    : AudioNode(context, sampleRate)
41{
42    addInput(adoptPtr(new AudioNodeInput(this)));
43    addOutput(adoptPtr(new AudioNodeOutput(this, 0)));
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    // The realtime thread can't block on this lock, so we call tryLock() instead.
75    if (m_processLock.tryLock()) {
76        if (!isInitialized() || !processor())
77            destinationBus->zero();
78        else {
79            AudioBus* sourceBus = input(0)->bus();
80
81            // FIXME: if we take "tail time" into account, then we can avoid calling processor()->process() once the tail dies down.
82            if (!input(0)->isConnected())
83                sourceBus->zero();
84
85            processor()->process(sourceBus, destinationBus, framesToProcess);
86        }
87
88        m_processLock.unlock();
89    } else {
90        // Too bad - the tryLock() failed.  We must be in the middle of re-connecting and were already outputting silence anyway...
91        destinationBus->zero();
92    }
93}
94
95// Nice optimization in the very common case allowing for "in-place" processing
96void AudioBasicProcessorNode::pullInputs(size_t framesToProcess)
97{
98    // Render input stream - suggest to the input to render directly into output bus for in-place processing in process() if possible.
99    input(0)->pull(output(0)->bus(), framesToProcess);
100}
101
102void AudioBasicProcessorNode::reset()
103{
104    if (processor())
105        processor()->reset();
106}
107
108// As soon as we know the channel count of our input, we can lazily initialize.
109// Sometimes this may be called more than once with different channel counts, in which case we must safely
110// uninitialize and then re-initialize with the new channel count.
111void AudioBasicProcessorNode::checkNumberOfChannelsForInput(AudioNodeInput* input)
112{
113    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
114
115    ASSERT(input == this->input(0));
116    if (input != this->input(0))
117        return;
118
119    ASSERT(processor());
120    if (!processor())
121        return;
122
123    unsigned numberOfChannels = input->numberOfChannels();
124
125    if (isInitialized() && numberOfChannels != output(0)->numberOfChannels()) {
126        // We're already initialized but the channel count has changed.
127        // We need to be careful since we may be actively processing right now, so synchronize with process().
128        MutexLocker locker(m_processLock);
129        uninitialize();
130    }
131
132    if (!isInitialized()) {
133        // This will propagate the channel count to any nodes connected further down the chain...
134        output(0)->setNumberOfChannels(numberOfChannels);
135
136        // Re-initialize the processor with the new channel count.
137        processor()->setNumberOfChannels(numberOfChannels);
138        initialize();
139    }
140}
141
142unsigned AudioBasicProcessorNode::numberOfChannels()
143{
144    return output(0)->numberOfChannels();
145}
146
147} // namespace WebCore
148
149#endif // ENABLE(WEB_AUDIO)
150