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 AudioDestinationNode_h 26 #define AudioDestinationNode_h 27 28 #include "platform/audio/AudioBus.h" 29 #include "platform/audio/AudioIOCallback.h" 30 #include "platform/audio/AudioSourceProvider.h" 31 #include "modules/webaudio/AudioBuffer.h" 32 #include "modules/webaudio/AudioNode.h" 33 34 namespace WebCore { 35 36 class AudioBus; 37 class AudioContext; 38 39 class AudioDestinationNode : public AudioNode, public AudioIOCallback { 40 public: 41 AudioDestinationNode(AudioContext*, float sampleRate); 42 virtual ~AudioDestinationNode(); 43 44 // AudioNode process(size_t)45 virtual void process(size_t) OVERRIDE FINAL { } // we're pulled by hardware so this is never called 46 47 // The audio hardware calls render() to get the next render quantum of audio into destinationBus. 48 // It will optionally give us local/live audio input in sourceBus (if it's not 0). 49 virtual void render(AudioBus* sourceBus, AudioBus* destinationBus, size_t numberOfFrames) OVERRIDE FINAL; 50 currentSampleFrame()51 size_t currentSampleFrame() const { return m_currentSampleFrame; } currentTime()52 double currentTime() const { return currentSampleFrame() / static_cast<double>(sampleRate()); } 53 maxChannelCount()54 virtual unsigned long maxChannelCount() const { return 0; } 55 56 virtual void startRendering() = 0; 57 58 protected: 59 // LocalAudioInputProvider allows us to expose an AudioSourceProvider for local/live audio input. 60 // If there is local/live audio input, we call set() with the audio input data every render quantum. 61 class LocalAudioInputProvider FINAL : public AudioSourceProvider { 62 public: LocalAudioInputProvider()63 LocalAudioInputProvider() 64 : m_sourceBus(AudioBus::create(2, AudioNode::ProcessingSizeInFrames)) // FIXME: handle non-stereo local input. 65 { 66 } 67 set(AudioBus * bus)68 void set(AudioBus* bus) 69 { 70 if (bus) 71 m_sourceBus->copyFrom(*bus); 72 } 73 74 // AudioSourceProvider. provideInput(AudioBus * destinationBus,size_t numberOfFrames)75 virtual void provideInput(AudioBus* destinationBus, size_t numberOfFrames) OVERRIDE 76 { 77 bool isGood = destinationBus && destinationBus->length() == numberOfFrames && m_sourceBus->length() == numberOfFrames; 78 ASSERT(isGood); 79 if (isGood) 80 destinationBus->copyFrom(*m_sourceBus); 81 } 82 83 private: 84 RefPtr<AudioBus> m_sourceBus; 85 }; 86 tailTime()87 virtual double tailTime() const OVERRIDE FINAL { return 0; } latencyTime()88 virtual double latencyTime() const OVERRIDE FINAL { return 0; } 89 90 // Counts the number of sample-frames processed by the destination. 91 size_t m_currentSampleFrame; 92 93 LocalAudioInputProvider m_localAudioInputProvider; 94 }; 95 96 } // namespace WebCore 97 98 #endif // AudioDestinationNode_h 99