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
35using namespace std;
36
37namespace WebCore {
38
39AudioNodeInput::AudioNodeInput(AudioNode* node)
40    : AudioSummingJunction(node->context())
41    , m_node(node)
42{
43    // Set to mono by default.
44    m_internalSummingBus = AudioBus::create(1, AudioNode::ProcessingSizeInFrames);
45}
46
47void AudioNodeInput::connect(AudioNodeOutput* output)
48{
49    ASSERT(context()->isGraphOwner());
50
51    ASSERT(output && node());
52    if (!output || !node())
53        return;
54
55    // Check if we're already connected to this output.
56    if (m_outputs.contains(output))
57        return;
58
59    output->addInput(this);
60    m_outputs.add(output);
61    changedOutputs();
62
63    // Sombody has just connected to us, so count it as a reference.
64    node()->ref(AudioNode::RefTypeConnection);
65}
66
67void AudioNodeInput::disconnect(AudioNodeOutput* output)
68{
69    ASSERT(context()->isGraphOwner());
70
71    ASSERT(output && node());
72    if (!output || !node())
73        return;
74
75    // First try to disconnect from "active" connections.
76    if (m_outputs.contains(output)) {
77        m_outputs.remove(output);
78        changedOutputs();
79        output->removeInput(this);
80        node()->deref(AudioNode::RefTypeConnection); // Note: it's important to return immediately after all deref() calls since the node may be deleted.
81        return;
82    }
83
84    // Otherwise, try to disconnect from disabled connections.
85    if (m_disabledOutputs.contains(output)) {
86        m_disabledOutputs.remove(output);
87        output->removeInput(this);
88        node()->deref(AudioNode::RefTypeConnection); // Note: it's important to return immediately after all deref() calls 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
99    ASSERT(output && node());
100    if (!output || !node())
101        return;
102
103    ASSERT(m_outputs.contains(output));
104
105    m_disabledOutputs.add(output);
106    m_outputs.remove(output);
107    changedOutputs();
108
109    // Propagate disabled state to outputs.
110    node()->disableOutputsIfNecessary();
111}
112
113void AudioNodeInput::enable(AudioNodeOutput* output)
114{
115    ASSERT(context()->isGraphOwner());
116
117    ASSERT(output && node());
118    if (!output || !node())
119        return;
120
121    ASSERT(m_disabledOutputs.contains(output));
122
123    // Move output from disabled list to active list.
124    m_outputs.add(output);
125    m_disabledOutputs.remove(output);
126    changedOutputs();
127
128    // Propagate enabled state to outputs.
129    node()->enableOutputsIfNecessary();
130}
131
132void AudioNodeInput::didUpdate()
133{
134    node()->checkNumberOfChannelsForInput(this);
135}
136
137void AudioNodeInput::updateInternalBus()
138{
139    ASSERT(context()->isAudioThread() && context()->isGraphOwner());
140
141    unsigned numberOfInputChannels = numberOfChannels();
142
143    if (numberOfInputChannels == m_internalSummingBus->numberOfChannels())
144        return;
145
146    m_internalSummingBus = AudioBus::create(numberOfInputChannels, AudioNode::ProcessingSizeInFrames);
147}
148
149unsigned AudioNodeInput::numberOfChannels() const
150{
151    AudioNode::ChannelCountMode mode = node()->internalChannelCountMode();
152    if (mode == AudioNode::Explicit)
153        return node()->channelCount();
154
155    // Find the number of channels of the connection with the largest number of channels.
156    unsigned maxChannels = 1; // one channel is the minimum allowed
157
158    for (HashSet<AudioNodeOutput*>::iterator i = m_outputs.begin(); i != m_outputs.end(); ++i) {
159        AudioNodeOutput* output = *i;
160        // Use output()->numberOfChannels() instead of output->bus()->numberOfChannels(),
161        // because the calling of AudioNodeOutput::bus() is not safe here.
162        maxChannels = max(maxChannels, output->numberOfChannels());
163    }
164
165    if (mode == AudioNode::ClampedMax)
166        maxChannels = min(maxChannels, static_cast<unsigned>(node()->channelCount()));
167
168    return maxChannels;
169}
170
171AudioBus* AudioNodeInput::bus()
172{
173    ASSERT(context()->isAudioThread());
174
175    // Handle single connection specially to allow for in-place processing.
176    if (numberOfRenderingConnections() == 1 && node()->internalChannelCountMode() == AudioNode::Max)
177        return renderingOutput(0)->bus();
178
179    // Multiple connections case or complex ChannelCountMode (or no connections).
180    return internalSummingBus();
181}
182
183AudioBus* AudioNodeInput::internalSummingBus()
184{
185    ASSERT(context()->isAudioThread());
186
187    return m_internalSummingBus.get();
188}
189
190void AudioNodeInput::sumAllConnections(AudioBus* summingBus, size_t framesToProcess)
191{
192    ASSERT(context()->isAudioThread());
193
194    // We shouldn't be calling this method if there's only one connection, since it's less efficient.
195    ASSERT(numberOfRenderingConnections() > 1 || node()->internalChannelCountMode() != AudioNode::Max);
196
197    ASSERT(summingBus);
198    if (!summingBus)
199        return;
200
201    summingBus->zero();
202
203    AudioBus::ChannelInterpretation interpretation = node()->internalChannelInterpretation();
204
205    for (unsigned i = 0; i < numberOfRenderingConnections(); ++i) {
206        AudioNodeOutput* output = renderingOutput(i);
207        ASSERT(output);
208
209        // Render audio from this output.
210        AudioBus* connectionBus = output->pull(0, framesToProcess);
211
212        // Sum, with unity-gain.
213        summingBus->sumFrom(*connectionBus, interpretation);
214    }
215}
216
217AudioBus* AudioNodeInput::pull(AudioBus* inPlaceBus, size_t framesToProcess)
218{
219    ASSERT(context()->isAudioThread());
220
221    // Handle single connection case.
222    if (numberOfRenderingConnections() == 1 && node()->internalChannelCountMode() == AudioNode::Max) {
223        // The output will optimize processing using inPlaceBus if it's able.
224        AudioNodeOutput* output = this->renderingOutput(0);
225        return output->pull(inPlaceBus, framesToProcess);
226    }
227
228    AudioBus* internalSummingBus = this->internalSummingBus();
229
230    if (!numberOfRenderingConnections()) {
231        // At least, generate silence if we're not connected to anything.
232        // FIXME: if we wanted to get fancy, we could propagate a 'silent hint' here to optimize the downstream graph processing.
233        internalSummingBus->zero();
234        return internalSummingBus;
235    }
236
237    // Handle multiple connections case.
238    sumAllConnections(internalSummingBus, framesToProcess);
239
240    return internalSummingBus;
241}
242
243} // namespace WebCore
244
245#endif // ENABLE(WEB_AUDIO)
246