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#ifndef WebAudioBus_h
26#define WebAudioBus_h
27
28#include "WebCommon.h"
29
30#if INSIDE_BLINK
31namespace WTF { template <typename T> class PassRefPtr; }
32#endif
33
34namespace blink {
35
36class AudioBus;
37class WebAudioBusPrivate;
38
39// A container for multi-channel linear PCM audio data.
40//
41// WARNING: It is not safe to pass a WebAudioBus across threads!!!
42//
43class BLINK_PLATFORM_EXPORT WebAudioBus {
44public:
45    WebAudioBus() : m_private(0) { }
46    ~WebAudioBus() { reset(); }
47
48    // initialize() allocates memory of the given length for the given number of channels.
49    void initialize(unsigned numberOfChannels, size_t length, double sampleRate);
50
51    // resizeSmaller() can only be called after initialize() with a new length <= the initialization length.
52    // The data stored in the bus will remain undisturbed.
53    void resizeSmaller(size_t newLength);
54
55    // reset() releases the memory allocated from initialize().
56    void reset();
57
58    unsigned numberOfChannels() const;
59    size_t length() const;
60    double sampleRate() const;
61
62    float* channelData(unsigned channelIndex);
63
64#if INSIDE_BLINK
65    WTF::PassRefPtr<AudioBus> release();
66#endif
67
68private:
69    // Disallow copy and assign.
70    WebAudioBus(const WebAudioBus&);
71    void operator=(const WebAudioBus&);
72
73    AudioBus* m_private;
74};
75
76} // namespace blink
77
78#endif // WebAudioBus_h
79