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/AudioNodeOutput.h"
30
31#include "modules/webaudio/AudioContext.h"
32#include "modules/webaudio/AudioNodeInput.h"
33#include "wtf/Threading.h"
34
35namespace blink {
36
37inline AudioNodeOutput::AudioNodeOutput(AudioNode* node, unsigned numberOfChannels)
38    : m_node(node)
39    , m_numberOfChannels(numberOfChannels)
40    , m_desiredNumberOfChannels(numberOfChannels)
41    , m_isInPlace(false)
42    , m_isEnabled(true)
43#if ENABLE_ASSERT
44    , m_didCallDispose(false)
45#endif
46    , m_renderingFanOutCount(0)
47    , m_renderingParamFanOutCount(0)
48{
49    ASSERT(numberOfChannels <= AudioContext::maxNumberOfChannels());
50
51    m_internalBus = AudioBus::create(numberOfChannels, AudioNode::ProcessingSizeInFrames);
52}
53
54AudioNodeOutput* AudioNodeOutput::create(AudioNode* node, unsigned numberOfChannels)
55{
56    return new AudioNodeOutput(node, numberOfChannels);
57}
58
59void AudioNodeOutput::trace(Visitor* visitor)
60{
61    visitor->trace(m_node);
62    visitor->trace(m_inputs);
63    visitor->trace(m_params);
64}
65
66void AudioNodeOutput::dispose()
67{
68#if ENABLE_ASSERT
69    m_didCallDispose = true;
70#endif
71    context()->removeMarkedAudioNodeOutput(this);
72}
73
74void AudioNodeOutput::setNumberOfChannels(unsigned numberOfChannels)
75{
76    ASSERT(numberOfChannels <= AudioContext::maxNumberOfChannels());
77    ASSERT(context()->isGraphOwner());
78
79    m_desiredNumberOfChannels = numberOfChannels;
80
81    if (context()->isAudioThread()) {
82        // If we're in the audio thread then we can take care of it right away (we should be at the very start or end of a rendering quantum).
83        updateNumberOfChannels();
84    } else {
85        ASSERT(!m_didCallDispose);
86        // Let the context take care of it in the audio thread in the pre and post render tasks.
87        context()->markAudioNodeOutputDirty(this);
88    }
89}
90
91void AudioNodeOutput::updateInternalBus()
92{
93    if (numberOfChannels() == m_internalBus->numberOfChannels())
94        return;
95
96    m_internalBus = AudioBus::create(numberOfChannels(), AudioNode::ProcessingSizeInFrames);
97}
98
99void AudioNodeOutput::updateRenderingState()
100{
101    updateNumberOfChannels();
102    m_renderingFanOutCount = fanOutCount();
103    m_renderingParamFanOutCount = paramFanOutCount();
104}
105
106void AudioNodeOutput::updateNumberOfChannels()
107{
108    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
109
110    if (m_numberOfChannels != m_desiredNumberOfChannels) {
111        m_numberOfChannels = m_desiredNumberOfChannels;
112        updateInternalBus();
113        propagateChannelCount();
114    }
115}
116
117void AudioNodeOutput::propagateChannelCount()
118{
119    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
120
121    if (isChannelCountKnown()) {
122        // Announce to any nodes we're connected to that we changed our channel count for its input.
123        for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i)
124            i->value->checkNumberOfChannelsForInput(i->key);
125    }
126}
127
128AudioBus* AudioNodeOutput::pull(AudioBus* inPlaceBus, size_t framesToProcess)
129{
130    ASSERT(context()->isAudioThread());
131    ASSERT(m_renderingFanOutCount > 0 || m_renderingParamFanOutCount > 0);
132
133    // Causes our AudioNode to process if it hasn't already for this render quantum.
134    // We try to do in-place processing (using inPlaceBus) if at all possible,
135    // but we can't process in-place if we're connected to more than one input (fan-out > 1).
136    // In this case pull() is called multiple times per rendering quantum, and the processIfNecessary() call below will
137    // cause our node to process() only the first time, caching the output in m_internalOutputBus for subsequent calls.
138
139    m_isInPlace = inPlaceBus && inPlaceBus->numberOfChannels() == numberOfChannels() && (m_renderingFanOutCount + m_renderingParamFanOutCount) == 1;
140
141    m_inPlaceBus = m_isInPlace ? inPlaceBus : 0;
142
143    node()->processIfNecessary(framesToProcess);
144    return bus();
145}
146
147AudioBus* AudioNodeOutput::bus() const
148{
149    ASSERT(const_cast<AudioNodeOutput*>(this)->context()->isAudioThread());
150    return m_isInPlace ? m_inPlaceBus.get() : m_internalBus.get();
151}
152
153unsigned AudioNodeOutput::fanOutCount()
154{
155    ASSERT(context()->isGraphOwner());
156    return m_inputs.size();
157}
158
159unsigned AudioNodeOutput::paramFanOutCount()
160{
161    ASSERT(context()->isGraphOwner());
162    return m_params.size();
163}
164
165unsigned AudioNodeOutput::renderingFanOutCount() const
166{
167    return m_renderingFanOutCount;
168}
169
170void AudioNodeOutput::addInput(AudioNodeInput& input)
171{
172    ASSERT(context()->isGraphOwner());
173    m_inputs.add(&input, &input.node());
174    input.node().makeConnection();
175}
176
177void AudioNodeOutput::removeInput(AudioNodeInput& input)
178{
179    ASSERT(context()->isGraphOwner());
180    input.node().breakConnection();
181    m_inputs.remove(&input);
182}
183
184void AudioNodeOutput::disconnectAllInputs()
185{
186    ASSERT(context()->isGraphOwner());
187
188    // AudioNodeInput::disconnect() changes m_inputs by calling removeInput().
189    while (!m_inputs.isEmpty())
190        m_inputs.begin()->key->disconnect(*this);
191}
192
193void AudioNodeOutput::addParam(AudioParam& param)
194{
195    ASSERT(context()->isGraphOwner());
196    m_params.add(&param);
197}
198
199void AudioNodeOutput::removeParam(AudioParam& param)
200{
201    ASSERT(context()->isGraphOwner());
202    m_params.remove(&param);
203}
204
205void AudioNodeOutput::disconnectAllParams()
206{
207    ASSERT(context()->isGraphOwner());
208
209    // AudioParam::disconnect() changes m_params by calling removeParam().
210    while (!m_params.isEmpty())
211        (*m_params.begin())->disconnect(*this);
212}
213
214void AudioNodeOutput::disconnectAll()
215{
216    disconnectAllInputs();
217    disconnectAllParams();
218}
219
220void AudioNodeOutput::disable()
221{
222    ASSERT(context()->isGraphOwner());
223
224    if (m_isEnabled) {
225        m_isEnabled = false;
226        for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i)
227            i->key->disable(*this);
228    }
229}
230
231void AudioNodeOutput::enable()
232{
233    ASSERT(context()->isGraphOwner());
234
235    if (!m_isEnabled) {
236        m_isEnabled = true;
237        for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i)
238            i->key->enable(*this);
239    }
240}
241
242} // namespace blink
243
244#endif // ENABLE(WEB_AUDIO)
245