| /* |
| * Copyright (C) 2010 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef AudioDestination_h |
| #define AudioDestination_h |
| |
| #include "platform/PlatformExport.h" |
| #include "wtf/OwnPtr.h" |
| #include "wtf/PassOwnPtr.h" |
| #include "wtf/text/WTFString.h" |
| |
| namespace WebCore { |
| |
| class AudioIOCallback; |
| |
| // AudioDestination is an abstraction for audio hardware I/O. |
| // The audio hardware periodically calls the AudioIOCallback render() method asking it to render/output the next render quantum of audio. |
| // It optionally will pass in local/live audio input when it calls render(). |
| |
| class PLATFORM_EXPORT AudioDestination { |
| public: |
| // Pass in (numberOfInputChannels > 0) if live/local audio input is desired. |
| // Port-specific device identification information for live/local input streams can be passed in the inputDeviceId. |
| static PassOwnPtr<AudioDestination> create(AudioIOCallback&, const String& inputDeviceId, unsigned numberOfInputChannels, unsigned numberOfOutputChannels, float sampleRate); |
| |
| virtual ~AudioDestination() { } |
| |
| virtual void start() = 0; |
| virtual void stop() = 0; |
| virtual bool isPlaying() = 0; |
| |
| // Sample-rate conversion may happen in AudioDestination to the hardware sample-rate |
| virtual float sampleRate() const = 0; |
| static float hardwareSampleRate(); |
| |
| // maxChannelCount() returns the total number of output channels of the audio hardware. |
| // A value of 0 indicates that the number of channels cannot be configured and |
| // that only stereo (2-channel) destinations can be created. |
| // The numberOfOutputChannels parameter of AudioDestination::create() is allowed to |
| // be a value: 1 <= numberOfOutputChannels <= maxChannelCount(), |
| // or if maxChannelCount() equals 0, then numberOfOutputChannels must be 2. |
| static unsigned long maxChannelCount(); |
| }; |
| |
| } // namespace WebCore |
| |
| #endif // AudioDestination_h |