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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef AudioBuffer_h
30#define AudioBuffer_h
31
32#include "Float32Array.h"
33#include <wtf/PassRefPtr.h>
34#include <wtf/RefCounted.h>
35#include <wtf/RefPtr.h>
36#include <wtf/Vector.h>
37
38namespace WebCore {
39
40class AudioBus;
41
42class AudioBuffer : public RefCounted<AudioBuffer> {
43public:
44    static PassRefPtr<AudioBuffer> create(unsigned numberOfChannels, size_t numberOfFrames, double sampleRate);
45
46    // Returns 0 if data is not a valid audio file.
47    static PassRefPtr<AudioBuffer> createFromAudioFileData(const void* data, size_t dataSize, bool mixToMono, double sampleRate);
48
49    // Format
50    size_t length() const { return m_length; }
51    double duration() const { return length() / sampleRate(); }
52    double sampleRate() const { return m_sampleRate; }
53
54    // Channel data access
55    unsigned numberOfChannels() const { return m_channels.size(); }
56    Float32Array* getChannelData(unsigned channelIndex);
57    void zero();
58
59    // Scalar gain
60    double gain() const { return m_gain; }
61    void setGain(double gain) { m_gain = gain; }
62
63    // Because an AudioBuffer has a JavaScript wrapper, which will be garbage collected, it may take awhile for this object to be deleted.
64    // releaseMemory() can be called when the AudioContext goes away, so we can release the memory earlier than when the garbage collection happens.
65    // Careful! Only call this when the page unloads, after the AudioContext is no longer processing.
66    void releaseMemory();
67
68protected:
69    AudioBuffer(unsigned numberOfChannels, size_t numberOfFrames, double sampleRate);
70    AudioBuffer(AudioBus* bus);
71
72    double m_gain; // scalar gain
73    double m_sampleRate;
74    size_t m_length;
75
76    Vector<RefPtr<Float32Array> > m_channels;
77};
78
79} // namespace WebCore
80
81#endif // AudioBuffer_h
82