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 "AudioDestinationNode.h"
30
31 #include "AudioBus.h"
32 #include "AudioContext.h"
33 #include "AudioNodeInput.h"
34 #include "AudioNodeOutput.h"
35
36 namespace WebCore {
37
AudioDestinationNode(AudioContext * context,double sampleRate)38 AudioDestinationNode::AudioDestinationNode(AudioContext* context, double sampleRate)
39 : AudioNode(context, sampleRate)
40 , m_currentTime(0.0)
41 {
42 addInput(adoptPtr(new AudioNodeInput(this)));
43
44 setType(NodeTypeDestination);
45 }
46
~AudioDestinationNode()47 AudioDestinationNode::~AudioDestinationNode()
48 {
49 uninitialize();
50 }
51
52 // The audio hardware calls us back here to gets its input stream.
provideInput(AudioBus * destinationBus,size_t numberOfFrames)53 void AudioDestinationNode::provideInput(AudioBus* destinationBus, size_t numberOfFrames)
54 {
55 context()->setAudioThread(currentThread());
56
57 if (!context()->isRunnable()) {
58 destinationBus->zero();
59 return;
60 }
61
62 // Let the context take care of any business at the start of each render quantum.
63 context()->handlePreRenderTasks();
64
65 // This will cause the node(s) connected to us to process, which in turn will pull on their input(s),
66 // all the way backwards through the rendering graph.
67 AudioBus* renderedBus = input(0)->pull(destinationBus, numberOfFrames);
68
69 if (!renderedBus)
70 destinationBus->zero();
71 else if (renderedBus != destinationBus) {
72 // in-place processing was not possible - so copy
73 destinationBus->copyFrom(*renderedBus);
74 }
75
76 // Let the context take care of any business at the end of each render quantum.
77 context()->handlePostRenderTasks();
78
79 // Advance current time.
80 m_currentTime += numberOfFrames / sampleRate();
81 }
82
83 } // namespace WebCore
84
85 #endif // ENABLE(WEB_AUDIO)
86