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/AudioNodeInput.h"
30
31#include "modules/webaudio/AudioContext.h"
32#include "modules/webaudio/AudioNodeOutput.h"
33#include <algorithm>
34
35namespace blink {
36
37inline AudioNodeInput::AudioNodeInput(AudioNode& node)
38    : AudioSummingJunction(node.context())
39    , m_node(node)
40{
41    // Set to mono by default.
42    m_internalSummingBus = AudioBus::create(1, AudioNode::ProcessingSizeInFrames);
43}
44
45AudioNodeInput* AudioNodeInput::create(AudioNode& node)
46{
47    return new AudioNodeInput(node);
48}
49
50void AudioNodeInput::trace(Visitor* visitor)
51{
52    visitor->trace(m_node);
53    AudioSummingJunction::trace(visitor);
54}
55
56void AudioNodeInput::connect(AudioNodeOutput& output)
57{
58    ASSERT(context()->isGraphOwner());
59
60    // Check if we're already connected to this output.
61    if (m_outputs.contains(&output))
62        return;
63
64    output.addInput(*this);
65    m_outputs.add(&output);
66    changedOutputs();
67}
68
69void AudioNodeInput::disconnect(AudioNodeOutput& output)
70{
71    ASSERT(context()->isGraphOwner());
72
73    // First try to disconnect from "active" connections.
74    if (m_outputs.contains(&output)) {
75        m_outputs.remove(&output);
76        changedOutputs();
77        output.removeInput(*this);
78        // Note: it's important to return immediately after removeInput() calls
79        // since the node may be deleted.
80        return;
81    }
82
83    // Otherwise, try to disconnect from disabled connections.
84    if (m_disabledOutputs.contains(&output)) {
85        m_disabledOutputs.remove(&output);
86        output.removeInput(*this);
87        // Note: it's important to return immediately after all removeInput() calls
88        // since the node may be deleted.
89        return;
90    }
91
92    ASSERT_NOT_REACHED();
93}
94
95void AudioNodeInput::disable(AudioNodeOutput& output)
96{
97    ASSERT(context()->isGraphOwner());
98    ASSERT(m_outputs.contains(&output));
99
100    m_disabledOutputs.add(&output);
101    m_outputs.remove(&output);
102    changedOutputs();
103
104    // Propagate disabled state to outputs.
105    node().disableOutputsIfNecessary();
106}
107
108void AudioNodeInput::enable(AudioNodeOutput& output)
109{
110    ASSERT(context()->isGraphOwner());
111    ASSERT(m_disabledOutputs.contains(&output));
112
113    // Move output from disabled list to active list.
114    m_outputs.add(&output);
115    m_disabledOutputs.remove(&output);
116    changedOutputs();
117
118    // Propagate enabled state to outputs.
119    node().enableOutputsIfNecessary();
120}
121
122void AudioNodeInput::didUpdate()
123{
124    node().checkNumberOfChannelsForInput(this);
125}
126
127void AudioNodeInput::updateInternalBus()
128{
129    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
130
131    unsigned numberOfInputChannels = numberOfChannels();
132
133    if (numberOfInputChannels == m_internalSummingBus->numberOfChannels())
134        return;
135
136    m_internalSummingBus = AudioBus::create(numberOfInputChannels, AudioNode::ProcessingSizeInFrames);
137}
138
139unsigned AudioNodeInput::numberOfChannels() const
140{
141    AudioNode::ChannelCountMode mode = node().internalChannelCountMode();
142    if (mode == AudioNode::Explicit)
143        return node().channelCount();
144
145    // Find the number of channels of the connection with the largest number of channels.
146    unsigned maxChannels = 1; // one channel is the minimum allowed
147
148    for (HashSet<AudioNodeOutput*>::iterator i = m_outputs.begin(); i != m_outputs.end(); ++i) {
149        AudioNodeOutput* output = *i;
150        // Use output()->numberOfChannels() instead of output->bus()->numberOfChannels(),
151        // because the calling of AudioNodeOutput::bus() is not safe here.
152        maxChannels = std::max(maxChannels, output->numberOfChannels());
153    }
154
155    if (mode == AudioNode::ClampedMax)
156        maxChannels = std::min(maxChannels, static_cast<unsigned>(node().channelCount()));
157
158    return maxChannels;
159}
160
161AudioBus* AudioNodeInput::bus()
162{
163    ASSERT(context()->isAudioThread());
164
165    // Handle single connection specially to allow for in-place processing.
166    if (numberOfRenderingConnections() == 1 && node().internalChannelCountMode() == AudioNode::Max)
167        return renderingOutput(0)->bus();
168
169    // Multiple connections case or complex ChannelCountMode (or no connections).
170    return internalSummingBus();
171}
172
173AudioBus* AudioNodeInput::internalSummingBus()
174{
175    ASSERT(context()->isAudioThread());
176
177    return m_internalSummingBus.get();
178}
179
180void AudioNodeInput::sumAllConnections(AudioBus* summingBus, size_t framesToProcess)
181{
182    ASSERT(context()->isAudioThread());
183
184    // We shouldn't be calling this method if there's only one connection, since it's less efficient.
185    ASSERT(numberOfRenderingConnections() > 1 || node().internalChannelCountMode() != AudioNode::Max);
186
187    ASSERT(summingBus);
188    if (!summingBus)
189        return;
190
191    summingBus->zero();
192
193    AudioBus::ChannelInterpretation interpretation = node().internalChannelInterpretation();
194
195    for (unsigned i = 0; i < numberOfRenderingConnections(); ++i) {
196        AudioNodeOutput* output = renderingOutput(i);
197        ASSERT(output);
198
199        // Render audio from this output.
200        AudioBus* connectionBus = output->pull(0, framesToProcess);
201
202        // Sum, with unity-gain.
203        summingBus->sumFrom(*connectionBus, interpretation);
204    }
205}
206
207AudioBus* AudioNodeInput::pull(AudioBus* inPlaceBus, size_t framesToProcess)
208{
209    ASSERT(context()->isAudioThread());
210
211    // Handle single connection case.
212    if (numberOfRenderingConnections() == 1 && node().internalChannelCountMode() == AudioNode::Max) {
213        // The output will optimize processing using inPlaceBus if it's able.
214        AudioNodeOutput* output = this->renderingOutput(0);
215        return output->pull(inPlaceBus, framesToProcess);
216    }
217
218    AudioBus* internalSummingBus = this->internalSummingBus();
219
220    if (!numberOfRenderingConnections()) {
221        // At least, generate silence if we're not connected to anything.
222        // FIXME: if we wanted to get fancy, we could propagate a 'silent hint' here to optimize the downstream graph processing.
223        internalSummingBus->zero();
224        return internalSummingBus;
225    }
226
227    // Handle multiple connections case.
228    sumAllConnections(internalSummingBus, framesToProcess);
229
230    return internalSummingBus;
231}
232
233} // namespace blink
234
235#endif // ENABLE(WEB_AUDIO)
236