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/ChannelSplitterNode.h"
30
31 #include "modules/webaudio/AudioContext.h"
32 #include "modules/webaudio/AudioNodeInput.h"
33 #include "modules/webaudio/AudioNodeOutput.h"
34
35 namespace WebCore {
36
create(AudioContext * context,float sampleRate,unsigned numberOfOutputs)37 PassRefPtr<ChannelSplitterNode> ChannelSplitterNode::create(AudioContext* context, float sampleRate, unsigned numberOfOutputs)
38 {
39 if (!numberOfOutputs || numberOfOutputs > AudioContext::maxNumberOfChannels())
40 return 0;
41
42 return adoptRef(new ChannelSplitterNode(context, sampleRate, numberOfOutputs));
43 }
44
ChannelSplitterNode(AudioContext * context,float sampleRate,unsigned numberOfOutputs)45 ChannelSplitterNode::ChannelSplitterNode(AudioContext* context, float sampleRate, unsigned numberOfOutputs)
46 : AudioNode(context, sampleRate)
47 {
48 ScriptWrappable::init(this);
49 addInput(adoptPtr(new AudioNodeInput(this)));
50
51 // Create a fixed number of outputs (able to handle the maximum number of channels fed to an input).
52 for (unsigned i = 0; i < numberOfOutputs; ++i)
53 addOutput(adoptPtr(new AudioNodeOutput(this, 1)));
54
55 setNodeType(NodeTypeChannelSplitter);
56 initialize();
57 }
58
process(size_t framesToProcess)59 void ChannelSplitterNode::process(size_t framesToProcess)
60 {
61 AudioBus* source = input(0)->bus();
62 ASSERT(source);
63 ASSERT_UNUSED(framesToProcess, framesToProcess == source->length());
64
65 unsigned numberOfSourceChannels = source->numberOfChannels();
66
67 for (unsigned i = 0; i < numberOfOutputs(); ++i) {
68 AudioBus* destination = output(i)->bus();
69 ASSERT(destination);
70
71 if (i < numberOfSourceChannels) {
72 // Split the channel out if it exists in the source.
73 // It would be nice to avoid the copy and simply pass along pointers, but this becomes extremely difficult with fanout and fanin.
74 destination->channel(0)->copyFrom(source->channel(i));
75 } else if (output(i)->renderingFanOutCount() > 0) {
76 // Only bother zeroing out the destination if it's connected to anything
77 destination->zero();
78 }
79 }
80 }
81
reset()82 void ChannelSplitterNode::reset()
83 {
84 }
85
86 } // namespace WebCore
87
88 #endif // ENABLE(WEB_AUDIO)
89