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 "AudioNodeInput.h"
30
31#include "AudioContext.h"
32#include "AudioNode.h"
33#include "AudioNodeOutput.h"
34#include <algorithm>
35
36namespace WebCore {
37
38AudioNodeInput::AudioNodeInput(AudioNode* node)
39 : AudioSummingJunction(node->context())
40 , m_node(node)
41{
42 // Set to mono by default.
43 m_internalSummingBus = AudioBus::create(1, AudioNode::ProcessingSizeInFrames);
44}
45
46void AudioNodeInput::connect(AudioNodeOutput* output)
47{
48 ASSERT(context().isGraphOwner());
49
50 ASSERT(output && node());
51 if (!output || !node())
52 return;
53
54 // Check if we're already connected to this output.
55 if (!m_outputs.add(output).isNewEntry)
56 return;
57
58 output->addInput(this);
59 changedOutputs();
60
61 // Sombody has just connected to us, so count it as a reference.
62 node()->ref(AudioNode::RefTypeConnection);
63}
64
65void AudioNodeInput::disconnect(AudioNodeOutput* output)
66{
67 ASSERT(context().isGraphOwner());
68
69 ASSERT(output && node());
70 if (!output || !node())
71 return;
72
73 // First try to disconnect from "active" connections.
74 if (m_outputs.remove(output)) {
75 changedOutputs();
76 output->removeInput(this);
77 node()->deref(AudioNode::RefTypeConnection); // Note: it's important to return immediately after all deref() calls since the node may be deleted.
78 return;
79 }
80
81 // Otherwise, try to disconnect from disabled connections.
82 if (m_disabledOutputs.remove(output)) {
83 output->removeInput(this);
84 node()->deref(AudioNode::RefTypeConnection); // Note: it's important to return immediately after all deref() calls since the node may be deleted.
85 return;
86 }
87
88 ASSERT_NOT_REACHED();
89}
90
91void AudioNodeInput::disable(AudioNodeOutput* output)
92{
93 ASSERT(context().isGraphOwner());
94
95 ASSERT(output && node());
96 if (!output || !node())
97 return;
98
99 ASSERT(m_outputs.contains(output));
100
101 m_disabledOutputs.add(output);
102 m_outputs.remove(output);
103 changedOutputs();
104
105 // Propagate disabled state to outputs.
106 node()->disableOutputsIfNecessary();
107}
108
109void AudioNodeInput::enable(AudioNodeOutput* output)
110{
111 ASSERT(context().isGraphOwner());
112
113 ASSERT(output && node());
114 if (!output || !node())
115 return;
116
117 ASSERT(m_disabledOutputs.contains(output));
118
119 // Move output from disabled list to active list.
120 m_outputs.add(output);
121 m_disabledOutputs.remove(output);
122 changedOutputs();
123
124 // Propagate enabled state to outputs.
125 node()->enableOutputsIfNecessary();
126}
127
128void AudioNodeInput::didUpdate()
129{
130 node()->checkNumberOfChannelsForInput(this);
131}
132
133void AudioNodeInput::updateInternalBus()
134{
135 ASSERT(context().isAudioThread() && context().isGraphOwner());
136
137 unsigned numberOfInputChannels = numberOfChannels();
138
139 if (numberOfInputChannels == m_internalSummingBus->numberOfChannels())
140 return;
141
142 m_internalSummingBus = AudioBus::create(numberOfInputChannels, AudioNode::ProcessingSizeInFrames);
143}
144
145unsigned AudioNodeInput::numberOfChannels() const
146{
147 AudioNode::ChannelCountMode mode = node()->internalChannelCountMode();
148 if (mode == AudioNode::Explicit)
149 return node()->channelCount();
150
151 // Find the number of channels of the connection with the largest number of channels.
152 unsigned maxChannels = 1; // one channel is the minimum allowed
153
154 for (auto& output : m_outputs) {
155 // Use output()->numberOfChannels() instead of output->bus()->numberOfChannels(),
156 // because the calling of AudioNodeOutput::bus() is not safe here.
157 maxChannels = std::max(maxChannels, output->numberOfChannels());
158 }
159
160 if (mode == AudioNode::ClampedMax)
161 maxChannels = std::min(maxChannels, static_cast<unsigned>(node()->channelCount()));
162
163 return maxChannels;
164}
165
166AudioBus* AudioNodeInput::bus()
167{
168 ASSERT(context().isAudioThread());
169
170 // Handle single connection specially to allow for in-place processing.
171 if (numberOfRenderingConnections() == 1 && node()->internalChannelCountMode() == AudioNode::Max)
172 return renderingOutput(0)->bus();
173
174 // Multiple connections case or complex ChannelCountMode (or no connections).
175 return internalSummingBus();
176}
177
178AudioBus* AudioNodeInput::internalSummingBus()
179{
180 ASSERT(context().isAudioThread());
181
182 return m_internalSummingBus.get();
183}
184
185void AudioNodeInput::sumAllConnections(AudioBus* summingBus, size_t framesToProcess)
186{
187 ASSERT(context().isAudioThread());
188
189 // We shouldn't be calling this method if there's only one connection, since it's less efficient.
190 ASSERT(numberOfRenderingConnections() > 1 || node()->internalChannelCountMode() != AudioNode::Max);
191
192 ASSERT(summingBus);
193 if (!summingBus)
194 return;
195
196 summingBus->zero();
197
198 AudioBus::ChannelInterpretation interpretation = node()->internalChannelInterpretation();
199
200 for (auto& output : m_renderingOutputs) {
201 ASSERT(output);
202
203 // Render audio from this output.
204 AudioBus* connectionBus = output->pull(0, framesToProcess);
205
206 // Sum, with unity-gain.
207 summingBus->sumFrom(*connectionBus, interpretation);
208 }
209}
210
211AudioBus* AudioNodeInput::pull(AudioBus* inPlaceBus, size_t framesToProcess)
212{
213 ASSERT(context().isAudioThread());
214
215 // Handle single connection case.
216 if (numberOfRenderingConnections() == 1 && node()->internalChannelCountMode() == AudioNode::Max) {
217 // The output will optimize processing using inPlaceBus if it's able.
218 AudioNodeOutput* output = this->renderingOutput(0);
219 return output->pull(inPlaceBus, framesToProcess);
220 }
221
222 AudioBus* internalSummingBus = this->internalSummingBus();
223
224 if (!numberOfRenderingConnections()) {
225 // At least, generate silence if we're not connected to anything.
226 // FIXME: if we wanted to get fancy, we could propagate a 'silent hint' here to optimize the downstream graph processing.
227 internalSummingBus->zero();
228 return internalSummingBus;
229 }
230
231 // Handle multiple connections case.
232 sumAllConnections(internalSummingBus, framesToProcess);
233
234 return internalSummingBus;
235}
236
237} // namespace WebCore
238
239#endif // ENABLE(WEB_AUDIO)
240