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/AudioDestinationNode.h"
30
31 #include "platform/audio/AudioUtilities.h"
32 #include "platform/audio/DenormalDisabler.h"
33 #include "modules/webaudio/AudioContext.h"
34 #include "modules/webaudio/AudioNodeInput.h"
35 #include "modules/webaudio/AudioNodeOutput.h"
36
37 namespace blink {
38
AudioDestinationNode(AudioContext * context,float sampleRate)39 AudioDestinationNode::AudioDestinationNode(AudioContext* context, float sampleRate)
40 : AudioNode(context, sampleRate)
41 , m_currentSampleFrame(0)
42 {
43 addInput();
44
45 setNodeType(NodeTypeDestination);
46 }
47
~AudioDestinationNode()48 AudioDestinationNode::~AudioDestinationNode()
49 {
50 ASSERT(!isInitialized());
51 }
52
dispose()53 void AudioDestinationNode::dispose()
54 {
55 uninitialize();
56 AudioNode::dispose();
57 }
58
render(AudioBus * sourceBus,AudioBus * destinationBus,size_t numberOfFrames)59 void AudioDestinationNode::render(AudioBus* sourceBus, AudioBus* destinationBus, size_t numberOfFrames)
60 {
61 // We don't want denormals slowing down any of the audio processing
62 // since they can very seriously hurt performance.
63 // This will take care of all AudioNodes because they all process within this scope.
64 DenormalDisabler denormalDisabler;
65
66 context()->setAudioThread(currentThread());
67
68 if (!context()->isInitialized()) {
69 destinationBus->zero();
70 return;
71 }
72
73 // Let the context take care of any business at the start of each render quantum.
74 context()->handlePreRenderTasks();
75
76 // Prepare the local audio input provider for this render quantum.
77 if (sourceBus)
78 m_localAudioInputProvider.set(sourceBus);
79
80 // This will cause the node(s) connected to us to process, which in turn will pull on their input(s),
81 // all the way backwards through the rendering graph.
82 AudioBus* renderedBus = input(0)->pull(destinationBus, numberOfFrames);
83
84 if (!renderedBus)
85 destinationBus->zero();
86 else if (renderedBus != destinationBus) {
87 // in-place processing was not possible - so copy
88 destinationBus->copyFrom(*renderedBus);
89 }
90
91 // Process nodes which need a little extra help because they are not connected to anything, but still need to process.
92 context()->processAutomaticPullNodes(numberOfFrames);
93
94 // Let the context take care of any business at the end of each render quantum.
95 context()->handlePostRenderTasks();
96
97 // Advance current sample-frame.
98 m_currentSampleFrame += numberOfFrames;
99 }
100
101 } // namespace blink
102
103 #endif // ENABLE(WEB_AUDIO)
104