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 AudioDestination_h
30#define AudioDestination_h
31
32#include "platform/audio/AudioBus.h"
33#include "platform/audio/AudioIOCallback.h"
34#include "platform/audio/AudioSourceProvider.h"
35#include "public/platform/WebAudioDevice.h"
36#include "public/platform/WebVector.h"
37#include "wtf/Noncopyable.h"
38#include "wtf/text/WTFString.h"
39
40namespace blink {
41
42class AudioFIFO;
43class AudioPullFIFO;
44
45// An AudioDestination using Chromium's audio system
46
47class PLATFORM_EXPORT AudioDestination : public WebAudioDevice::RenderCallback, public AudioSourceProvider {
48    WTF_MAKE_NONCOPYABLE(AudioDestination);
49public:
50    AudioDestination(AudioIOCallback&, const String& inputDeviceId, unsigned numberOfInputChannels, unsigned numberOfOutputChannels, float sampleRate);
51    virtual ~AudioDestination();
52
53    // Pass in (numberOfInputChannels > 0) if live/local audio input is desired.
54    // Port-specific device identification information for live/local input streams can be passed in the inputDeviceId.
55    static PassOwnPtr<AudioDestination> create(AudioIOCallback&, const String& inputDeviceId, unsigned numberOfInputChannels, unsigned numberOfOutputChannels, float sampleRate);
56
57    virtual void start();
58    virtual void stop();
59    bool isPlaying() { return m_isPlaying; }
60
61    float sampleRate() const { return m_sampleRate; }
62
63    // WebAudioDevice::RenderCallback
64    virtual void render(const WebVector<float*>& sourceData, const WebVector<float*>& audioData, size_t numberOfFrames) OVERRIDE;
65
66    // AudioSourceProvider
67    virtual void provideInput(AudioBus*, size_t framesToProcess) OVERRIDE;
68
69    static float hardwareSampleRate();
70
71    // maxChannelCount() returns the total number of output channels of the audio hardware.
72    // A value of 0 indicates that the number of channels cannot be configured and
73    // that only stereo (2-channel) destinations can be created.
74    // The numberOfOutputChannels parameter of AudioDestination::create() is allowed to
75    // be a value: 1 <= numberOfOutputChannels <= maxChannelCount(),
76    // or if maxChannelCount() equals 0, then numberOfOutputChannels must be 2.
77    static unsigned long maxChannelCount();
78
79private:
80    AudioIOCallback& m_callback;
81    unsigned m_numberOfOutputChannels;
82    RefPtr<AudioBus> m_inputBus;
83    RefPtr<AudioBus> m_renderBus;
84    float m_sampleRate;
85    bool m_isPlaying;
86    OwnPtr<WebAudioDevice> m_audioDevice;
87    size_t m_callbackBufferSize;
88
89    OwnPtr<AudioFIFO> m_inputFifo;
90    OwnPtr<AudioPullFIFO> m_fifo;
91};
92
93} // namespace blink
94
95#endif // AudioDestination_h
96