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#include "config.h" 26 27#if ENABLE(WEB_AUDIO) 28 29#include "RealtimeAnalyserNode.h" 30 31#include "AudioNodeInput.h" 32#include "AudioNodeOutput.h" 33 34namespace WebCore { 35 36RealtimeAnalyserNode::RealtimeAnalyserNode(AudioContext* context, double sampleRate) 37 : AudioNode(context, sampleRate) 38{ 39 addInput(adoptPtr(new AudioNodeInput(this))); 40 addOutput(adoptPtr(new AudioNodeOutput(this, 2))); 41 42 setType(NodeTypeAnalyser); 43 44 initialize(); 45} 46 47RealtimeAnalyserNode::~RealtimeAnalyserNode() 48{ 49 uninitialize(); 50} 51 52void RealtimeAnalyserNode::process(size_t framesToProcess) 53{ 54 AudioBus* outputBus = output(0)->bus(); 55 56 if (!isInitialized() || !input(0)->isConnected()) { 57 outputBus->zero(); 58 return; 59 } 60 61 AudioBus* inputBus = input(0)->bus(); 62 63 // Give the analyser the audio which is passing through this AudioNode. 64 m_analyser.writeInput(inputBus, framesToProcess); 65 66 // For in-place processing, our override of pullInputs() will just pass the audio data through unchanged if the channel count matches from input to output 67 // (resulting in inputBus == outputBus). Otherwise, do an up-mix to stereo. 68 if (inputBus != outputBus) 69 outputBus->copyFrom(*inputBus); 70} 71 72// We override pullInputs() as an optimization allowing this node to take advantage of in-place processing, 73// where the input is simply passed through unprocessed to the output. 74// Note: this only applies if the input and output channel counts match. 75void RealtimeAnalyserNode::pullInputs(size_t framesToProcess) 76{ 77 // Render input stream - try to render directly into output bus for pass-through processing where process() doesn't need to do anything... 78 input(0)->pull(output(0)->bus(), framesToProcess); 79} 80 81void RealtimeAnalyserNode::reset() 82{ 83 m_analyser.reset(); 84} 85 86} // namespace WebCore 87 88#endif // ENABLE(WEB_AUDIO) 89