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 "RealtimeAnalyserNode.h"
30
31#include "AudioNodeInput.h"
32#include "AudioNodeOutput.h"
33
34namespace WebCore {
35
36RealtimeAnalyserNode::RealtimeAnalyserNode(AudioContext* context, double sampleRate)
37    : AudioNode(context, sampleRate)
38{
39    addInput(adoptPtr(new AudioNodeInput(this)));
40    addOutput(adoptPtr(new AudioNodeOutput(this, 2)));
41
42    setType(NodeTypeAnalyser);
43
44    initialize();
45}
46
47RealtimeAnalyserNode::~RealtimeAnalyserNode()
48{
49    uninitialize();
50}
51
52void RealtimeAnalyserNode::process(size_t framesToProcess)
53{
54    AudioBus* outputBus = output(0)->bus();
55
56    if (!isInitialized() || !input(0)->isConnected()) {
57        outputBus->zero();
58        return;
59    }
60
61    AudioBus* inputBus = input(0)->bus();
62
63    // Give the analyser the audio which is passing through this AudioNode.
64    m_analyser.writeInput(inputBus, framesToProcess);
65
66    // For in-place processing, our override of pullInputs() will just pass the audio data through unchanged if the channel count matches from input to output
67    // (resulting in inputBus == outputBus).  Otherwise, do an up-mix to stereo.
68    if (inputBus != outputBus)
69        outputBus->copyFrom(*inputBus);
70}
71
72// We override pullInputs() as an optimization allowing this node to take advantage of in-place processing,
73// where the input is simply passed through unprocessed to the output.
74// Note: this only applies if the input and output channel counts match.
75void RealtimeAnalyserNode::pullInputs(size_t framesToProcess)
76{
77    // Render input stream - try to render directly into output bus for pass-through processing where process() doesn't need to do anything...
78    input(0)->pull(output(0)->bus(), framesToProcess);
79}
80
81void RealtimeAnalyserNode::reset()
82{
83    m_analyser.reset();
84}
85
86} // namespace WebCore
87
88#endif // ENABLE(WEB_AUDIO)
89